All posts by Andy

Your Guide to DPF Cleaners and DPF Cleaning

May 14, 2015 Andy 116 Comments

DPF Cleaners and DPF Cleaning – The Definitive Guide

This is the second iteration of this article. It has been updated to reflect the common problems encountered when tackling what are understood to be DPF blockages.

In this article, we will address the following questions:

What is a DPF?
Why do DPFs clog up?
Misdiagnosis and related common faults.
Reasons why a DPF cleaner may not work for you?
The correct logical steps to diagnose and fix a DPF blockage.

What is a DPF?

A DPF or Diesel Particulate Filter is a device integral to the operation of the exhaust emission control system. It captures particulate matter and hydrocarbons and stores them. Every so often, a regeneration process occurs where these deposits and particulates are burned off, converted to CO2, and vented out the exhaust.

Why do DPFs clog up? There are several contributing factors.

The first is the quality of the fuel. The second is the quality of the engine oil, and the third is the driving style and journey type. Diesel engines are not designed for short journeys or stop-start driving; such conditions create excess particulate matter in the emission control components. That means the DPF and other parts such as the EGR and catalytic convertor have more particulate waste to deal with.

The issue arises when the engine produces more particulate matter than the DPF can handle. Various symptoms may become evident such as engine hesitation or power loss. Eventually, an engine warning light informs you there’s an issue with the system, and if not resolved, the vehicle is put into a “limp home” mode, with reduced power.

If the system is clogged excessively, it is common for the ECU to prevent further regeneration. This is very lucrative for some dealerships and garages because, in their view, you have to replace the DPF, which can run four figures in cost. I can tell you categorically that the DPF can be cleaned unless it has failed catastrophically, even if it’s 100% saturated and the vehicle will barely run at idle. It can also be cleaned even if the ECU will no longer force a regeneration cycle with the help of diagnostic software. Furthermore, modern cleaning techniques and technology mean that the DPF does not have to be removed to be thoroughly cleaned but more on that later.

It is important to note that particulate matter that accumulates in the DPF is NOT just from the fuel and the combustion process. It’s usually a combination of those elements and engine oil. Oil can be blown through the crankcase breather system, but more commonly (on a diesel engine), it bypasses the piston rings and is poorly combusted. Those particulates then accumulate in the DPF. This is the reason you have mid-SAP and low-SAP oils. The theory is that such oils have lower ash content, which gives the DPF an easier life. In some cases, high ash content can damage the DPF because it cannot combust those types of particulates. Our experience differs from this as higher ash oils can prevent oil from being bypassed in the first place. However, that is a different subject for another day.

Resolving a Blocked DPF

Firstly, one of the most common mistakes is misdiagnosis. An emission control warning light or even a DPF warning light does NOT ALWAYS mean the DPF is blocked. This is much more common than you think, so do not assume the DPF must be blocked if your vehicle produces a DPF warning light.

For Example:

Emission warning lights are generally shared across the entire emission control system, so an EGR (exhaust gas recirculation) valve fault or similar can be the root cause of what first appears to be a DPF issue.
One of the most common faults is that the Pressure Differential Sensor that calculates the saturation level and reports an over-saturation condition to the ECU could be faulty. In other words, the DPF is fine, but the sensor reports excess carbon and prevents a regeneration cycle. These sensors should be one of the first things checked, but they are often ignored. The result is an unhappy customer as the cleaning product or process “didn’t work.” It probably did, but the sensor is just reporting otherwise.
The ECU has identified the pressure sensor as faulty, which needs to be replaced rather than the DPF cleaned.

Secondly, and more important than the first, there MUST be an underlying reason for a DPF blockage if, in fact, it is actually blocked. The underlying causes should be established and, where possible, addressed accordingly.

For Example:

Fuel system deposits resulting in inefficient combustion can produce more carbonaceous matter than the DPF can manage. This can also apply to oil of low quality or incorrect specification. Is the engine consuming oil?
Driving style and journey types. Certain conditions must be met to enable the DPF to regenerate and manage the carbon build-up. Continuous low RPMs, stop/start driving, and short journeys that do not permit the engine and DPF to reach full operating temperature will eventually take their toll.
Other underlying faults, such as an injector or EGR issue, could prevent the DPF from regenerating. The ECU recognizes an underlying fault and “locks out” or prevents DPF regeneration cycles.
As mentioned above, the pressure differential sensor is faulty, misreading the level of backpressure between the front and rear of the DPF. The saturation level is only 10%, yet the sensor calculates 50% = game over until the sensor is replaced.

Therefore, as best as you can, it is essential to establish if there is a DPF blockage and if there is, or there is a high probability that there is, to identify the root cause(s). If not, you will be fighting a losing battle.

This is why fuel-based DPF cleaners and professional DPF cleaning are so hit and miss. Many users fail to diagnose and/or address the root cause correctly.

If a fuel-based DPF cleaner did not “work” then there is a good chance that the actual fault is not directly DPF related or that an underlying problem is forcing you into a lose-lose position. It is not always as straightforward as many make out, but I will make it as easy as possible.

Logical Steps to Resolving Suspected DPF Issues

STEPS	ACTION	APPROX. COSTS
1. Simple	If you suspect the DPF is blocked, then before you spend a penny on diagnostics or treatments, do this: Get the vehicle up to the full operating temperature, drive down the road and drop a couple of gears to get the engine revs above 3-3.5k. In other words, try to force a DPF regen.	Free other than the cost of fuel
2. Basics	If the above fails, you need to choose to use a fuel-based cleaner and/or investigate further. If using a cleaner, then combine it with step 1. It is a reasonable low-cost process of elimination. I would recommend a high-strength fuel system and engine cleaner first before using a dedicated DPF Cleaner OR use a fuel cleaner with a combined DPF cleaning function. A basic OBD / CAN BUS code reader can be purchased for as little as £10-£20. I recommend everyone keeps one in their car. If warning lights are visible, then the ECU will have stored codes, and rather than blindly guessing, you are well on your way to correctly diagnosing the issue or any underlying problems. If the codes indicate a DPF saturation issue, then this may be enough to justify using a high-quality fuel cleaner and/or dedicated DPF cleaner. The rationale for using a fuel cleaner first is that it will ensure the fuel system is clean (a common underlying fault) while also helping to clean the DPF by restoring combustion efficiency. Many fuel system cleaners and carbon removers also include catalyst technology that will actively remove carbon from the DPF anyway. Please don’t hesitate to contact us if you need help interpreting error codes or advice on the correct product choice.	High-Quality Fuel Cleaner – £20Code Reader – £10+Dedicated DPF Cleaner or combined Fuel and DPF Cleaner- £20+
3. Professional Diagnosis – Basic	If you don’t have a code reader, then a diesel specialist will be able to read the codes for you, leaving you with the choice to attempt the fuel cleaner-based route should the codes point to a genuine DPF blockage issue. If the Technician has the correct diagnostics tool, they should be able to attempt to force a regeneration cycle either on its own or aided by an in-tank DPF cleaner.	Basic Code Reading – £20+Forced Regen – £30+
4. Professional Diagnosis – FULL	A full diagnosis should include a full error code check and a test of the pressure differential sensor and other emissions control components that can create an apparent DPF issue. Basically, you want to confirm if the DPF is genuinely blocked, and if so, why? Or the technician needs to identify the underlying fault(s) creating the warning lights. If it looks like a DPF blockage, the first step is for the technician to attempt to force a regen cycle via the diagnostics tool. This is by far the cheapest fix before professional cleaning or worse, DPF removal.	Complete Diagnosis – £60+Plus any remedial treatment/repair costs.
5. Professional DPF Clean	If other underlying faults have been ruled out, a DPF blockage correctly diagnosed, and a fuel system cleaner plus DPF cleaner hasn’t worked. A professional clean would be the next logical step. Our recommendation would be a professional DPF Cleaning Kit. These are professional use products, so you will need to find a participating garage. This is a non-invasive process and is fully guaranteed. The garage will require the correct equipment to reset the DPF and, where necessary, force regeneration once cleaned.	Professional DPF Clean £200+

Further information:

In many cases, using a professional fuel system and carbon cleaner to ensure that the fuel system and injectors operate without deposits can be more important than using a dedicated DPF cleaner. Not only will a fuel system cleaner help clean the DPF anyway, but it will eliminate one of the most common contributory factors (dirty injectors) that, if not resolved, will allow the DPF to clog up again soon after. For this, we recommend the new Oilsyn Diesel Dr and DPF & Turbo or Archoil AR6400-D MAX.

You can use a generic cleaner that relies on the natural scavenging and cleaning mechanism (as described in the EGR cleaning article), or you can utilize one of the higher-end cleaners that use molecules activated during the combustion process (catalysts). These molecules bond with the hydrocarbons in the DPF and reduce the threshold temperature at which they can burn. By far, the best we have tested is the Oilsyn DPF & Turbo Dr. It contains chemistry comprising of carbon-removing molecules that are activated during the combustion process rather than destroyed like most fuel additives. This type of DPF cleaner combined with a spirited drive (or dropping down a gear) to create more heat will help to clean the DPF much more thoroughly. In genuine DPF blockage cases, these cleaners have some of the highest success rates of any DPF cleaning additives we have tested, reducing the saturation percentage, removing the engine warning light, and enabling passive regeneration.

It’s important to point out that heat is vital when removing carbon. So, using such a cleaner for short journeys will inhibit results. You have to combine them with a longer run and a driving style that permits the temperature within the DPF and the system in general to increase.

Suppose passive regeneration is not restored and the cleaner is not working. In that case, the DPF is oversaturated to the point that the ECU will not permit a regeneration cycle, the issue has been misdiagnosed, or another factor is restricting DPF regeneration. DPF regen could be locked out by the ECU rendering the system inoperable. It is also possible to have a vehicle so saturated that the back pressure is restricted so much that it will barely idle. For this, the DPF needs to be cleaned directly by a professional.

Professional Cleaning

It usually consists of a 2 step cleaning process that must be administered by a professional. The first of this series is sprayed directly in the DPF through the pressure sensor hose. The chemical bonds with the carbon to dissolve it and prepares for the next stage.

The second step involves holding high revs to burn off the carbon for a few minutes, followed by a flushing solution administered through the same hose. This removes any residual cleaning agents and deposits.

We recommend finding a garage local to you for this type of clean.

Maintaining a Clean DPF

Once the DPF is clean, it’s equally important to ensure that the particulates remain at a manageable level. I’ve already mentioned the importance of a professional fuel system cleaner to restore efficiency in the fuel injectors. I’d also recommend an ongoing fuel additive with a fuel catalyst or combustion modification technology, such as Oilsyn Diesel Power DNA or Archoil AR6900-D MAX. They will lower the number of hydrocarbons created in the first place. They reduce the threshold temperature at which the fuel is burned even when the engine is cold. So, even from the moment you start the engine, you’ll be producing fewer hydrocarbons. This is critical if your vehicle is just used for local trips (shopping runs, school runs, etc.). It gives the DPF a much easier life and will reduce its tendency to become oversaturated in the future. We have many reports from consumers and fleet owners that their vehicles regenerate much less when using Diesel Power DNA. The key is to keep the carbon production at a manageable level for the emission control system, and such additives achieve this.

Excessive Oil contamination

If the engine consumes oil, then unburnt oil can contaminate the DPF. During the next oil change, use a professional engine oil flush to restore lost compression, such as Oilsyn ReleaseTech Power Flush. As deposits build up on the piston rings, they push the rings away from the bore, thus allowing oil to bypass the rings and enter the combustion area. Once that happens, the DPF has to cope with an influx of particulates and more buildup.

Then use a high-quality oil and/or oil additive to retain correct compression and prevent any future deposit build-up. For this, we recommend any genuine synthetic oils (group IV or better) and/or Oilsyn Velosyn or Archoil AR9200 V2. This will keep the piston rings and bores clean and reduce the amount of oil entering the intake. Combine this with a fuel additive, and there’s no reason the DPF cannot outlive the vehicle itself without the need to use dedicated DPF cleaning procedures (invasive or otherwise).

I hope that helps. If you require any assistance, please don’t hesitate to contact us.

1295

Engine Tuning & Mapping

ECU Remapping and the Inadequate Preparation

April 30, 2015 Andy 2 Comments

There is now a multitude of companies that will remap the ECU on your vehicle. In most cases, this entails plugging a computer into the diagnostics port on your vehicle that directly communicates with the ECU. A technician reads the existing file on the ECU and overrides it with a new file. The new file has on it adjusted parameters that alter several characteristics of the engine. These include the amount of turbo boost pressure (if applicable), the fueling and ignition timing (if on a gasoline vehicle), and other such parameters.

After remapping a diesel engine, the exhaust’s smoke increases, particularly on heavy acceleration. Where you once had a small amount of smoke from your exhaust, you now have a problem with a severe amount of smoke. Any underlying running issues can be exacerbated with an engine remap. One thing that surprises me tremendously is that many companies do not carry out a health check. Many remap servicers are mobile; they do not have the necessary tools, equipment, or expertise to precheck the vehicle. As far as I have researched, barely any of them ensure that the fuel system is running correctly and that there isn’t an excess of carbon buildup.

If you push the engine by asking it to work harder and produce more power, you must ensure that you have the best platform to remap and gain that additional performance. To guarantee this, the first thing we advise is to carry out a health check. Make sure there are no error codes. Then combine the remap with a professional fuel system cleaner and carbon remover. The fuel system must be running efficiently before you remap your vehicle. On a petrol engine, it is essential that the ignition components, the ignition system, and the fuel system are performing optimally to maximize the benefits gained from a remap.

Wherever you go to have your vehicle remapped or chipped, ensure the service includes the necessary checks. Also, ensure you use a high-quality fuel system cleaner, particularly if your exhaust has any excess smoke. If you have extra smoke, I strongly advise resolving or checking the issue before performing a remap as it is likely to make it worse.

1647

Engine Tuning & Mapping

Why are ECU / Engine Remaps and Tuning Boxes so Effective?

April 30, 2015 Andy 10 Comments

When one purchases a vehicle, they likely expect engine ECUs to be optimally mapped prior to sale. While they are typically very well mapped, it is subjective whether or not it is done optimally.

In this article, I will look at engine/ECU remapping and chipping and the use of tuning boxes. I will explain why remapping works and, in most cases, why it is safe.

With most manufacturing, compromises have to be made. ECU maps are no different. Yes, manufacturers invest a great deal of time in engine tuning and testing in the harshest climates. However, tuning criteria are designed around extremes that do not necessarily fit the requirements of the average customer or where the vehicle will be used.

Manufacturers must adhere to and comply with various legislative constraints surrounding emissions and other parameters set by the different governing bodies. As a result, this may affect the quality of factory ECU maps regarding available performance and/or MPG.

Many manufacturers produce vehicles in their range that, to some degree, compete with each other and, in some cases, even share the same engine. For example, a VW Golf may share the same engine as a VW Polo or a Porsche Boxter competing with the Porsche 911. The point is that it would be marketing suicide for a Porsche 911 to be considered slower than its younger brother. As a result, some engines are intentionally detuned or, let’s say, not tuned to their full potential.

Furthermore, manufacturers are obligated to tune vehicles for wildly varying conditions, i.e., -40 to +130 degrees or very high altitudes where the air is much thinner. This is one of the reasons why engines run rich from the factory. It accommodates dramatic climatic conditions that the average driver will never see. Even with the latest technology in fuel and ignition control, compromises on engine tune still have to be made just in case the vehicle is used in such conditions.

Vehicles need to survive the factory warranty period without fault. For example, it’s not uncommon to find an engine that is detuned for torque output to ensure that the drivetrain doesn’t fail. This begs the question: Why would anyone want to remap/chip their vehicle if there is an increased risk of a component failure?

Well, here is the point I am trying to make here. Car manufacturers must tune vehicles to cater to mechanically unsympathetic customers! This is very important. Drivetrains or engines (as an example) can fail when they are abused or raced from cold. It is this type of customer and not your average enthusiast that manufacturers are trying to protect themselves against, at least within the factory warranty period.

Furthermore, fuel quality is not guaranteed. Customers embracing remaps are more inclined to use higher-quality branded fuels and/or fuel conditioners, unlike the average user. Manufacturers have little control over this, so engines are tuned accordingly and with a little to spare regarding turbo pressure, air/fuel ratio, ignition timing, etc.

A combination of the above is why we see so many forced induction engines running rich from the factory. This and all of the above give reputable tuners the opportunity to liberate additional performance safely and improve MPG from engines under certain conditions.

If in doubt, stick with reputable tuners and tuning box manufacturers, as this helps ensure you receive a well-developed tune.

Also, bear in mind that even though normally aspirated engines can be remapped, the gains are minimal when compared to forced induction engines. It would also be prudent to notify your car insurance provider.

UPDATE: We were asked how ECU remaps, or Tuning Boxes can improve MPG?

With naturally aspirated petrol engines, mpg gains are marginal at best. Minor adjustments can be made to ignition timing and air/fuel ratios, but both power and mpg gains are minimal. This is the case with virtually all non-forced induction engines.

With turbo or supercharged petrol engines, power gains are usually very good with tangible but small MPG gains. MPG gains are two-fold on forced induction petrol engines. Many turbocharged engines run very rich from the factory under acceleration (open loop lambda). By carefully leaning out the air/fuel mixture under open loop conditions, fuel consumption can be reduced. This is more difficult with more modern engines that utilise wideband lambda technology. That said, most gains (if any) are achieved by improving the spread of torque across the rev range or, in particular, lowering it. If more torque is available lower in the rev range, less throttle is required to achieve the same level of accelerative effort. Of course, more fuel may be required to achieve the additional torque but lowering engine RPM more than compensates for this. And this is where diesel engines excel…

Turbo diesel engines – excellent power (torque) gains and potential mpg gains. Most mpg gains are achieved in turbo diesel engines by using the principle described above – making more torque available lower in the rev range. If you used to use 40% throttle but now only have to use 35% throttle to achieve the same accelerative effort, then you will most likely save fuel once the novelty of the extra power has worn off!

I hope that helps.

1857

Fuel Addtives

Using Fuel Additives at Higher Dosages – Overdosing

March 13, 2015 Andy 14 Comments

I am regularly asked whether fuel additives can be added at a higher dose or added to less fuel to make a more potent concentrate and whether this is more beneficial.

The answer in most cases is no. This is because detergents, cetane improvers, dispersants, lubricants, etc., are designed to work with a specific amount of fuel. This ensures that any deposits are removed and dispersed in a controlled manner and aren’t purged through the system too quickly. It also reduces the risk of overloading the fuel with too much cetane improver or other functions that risk negating the benefits they set out to achieve.

For example, amine and Polyetheramine-based fuel cleaners work much better when used with the correct amount of fuel and gradually allow the chemistry to remove deposits in a controlled way. If you add a cleaner designed for sixty litres of fuel to ten litres of fuel, you run the risk of removing deposits too quickly and lose the benefit of the extended duration that sixty litres will provide.

Another reason for this is that fuel cleaners are designed to work with fuel flow where the actual act of removing deposits requires the fuel to be in motion. Deposits are removed layer by layer as the fuel moves through the system. The stronger the concentrate – and the less fuel that is treated – the lesser the amount of total motion that occurs. Amines dissolve and disperse deposits and prevent them from accumulating in the fuel system.

Therefore, do not be tempted to treat with a much higher concentration except when professionally instructed to do so and when, for example, a heavily-contaminated fuel injector requires urgent attention. In this instance, some cleaners can be safely added directly to the fuel rail or fuel filter. However, this procedure should be carried out by a professional and is not relevant to in-the-tank fuel cleaners.

Another question we are regularly asked is why some additives require a large amount of product, whereas others require such a small amount.

Higher-strength cleaners contain more chemistry and are designed to deliver the maximum amount of cleaning power and functions in a single bottle. Treat rates typically vary from 100:1 to 200:1. Regular use fuel conditioners are designed to deliver a modest amount of cleaning power and functions and are safe for continuous use. Treat rates vary from 500:1 to 10,000:1

Also, note that different chemistries work in different ways. High-strength cleaners, in particular, generally require a much larger volume of chemistry, pibsa, amine, polyetheramine, etc. Such cleaning power requires volume.

With a regular use 1,000:1 fuel conditioner, noticeable improvements might take a few tanks, whereas a higher strength single-tank cleaner will work within a single tank of fuel. The challenge is to deliver as many benefits as possible with the smallest amount of product.

1480

Engine Oils

Garages & Repair Centers Using Cheap Oil

March 13, 2015 Andy 3 Comments

There is a “cheap oil” endemic, and I am concerned for the consumer.

As suppliers of various lubricants, one of our tasks is to demonstrate to automatic transmission and gearbox rebuild specialists the benefits of using OE (original equipment) oils or at least lubricants that meet the required manufacturer’s specifications. This is much more difficult than you might think.

I am concerned about the percentage of repair shops that choose to use low-quality, or in many cases, the cheapest oils available. A customer can easily spend £1500, £3000, or even £5000+ on more complex automatic gearbox overhauls, and yet, the garage performing the work will use oil that costs them around £1.50 to £2.00 per liter. And their response when they are asked why they choose such cheap oil? Their answer is generally this: “As long as it lasts the twelve-month warranty period, it is fine.”

This raises an interesting concern, not just in the transmission rebuilding market but also with engine oil changes. I believe that as a consumer, you are perfectly within your rights to question and challenge the oil being installed in your vehicle, whether it’s the transmission fluid, engine oil, or any other fluid.

In virtually all cases, franchised dealers will use OE oils. That’s what your money is paying for and how they justify their excessive prices. While not always the best value or the highest quality, at least you receive an accepted and approved level of quality.

Our greatest concern is with some independent garages and repair centers. Too many garages still insist on “cheapest” and, in some cases oils that simply do not meet the specifications for your vehicle. For example, they use mid or high SAPS (sulfated ash, phosphorus, sulfur, etc.) oil with engines that are only designed to run on low SAPS oils. This is concerning because of the potential harm to the emission control components, such as the DPFs (Diesel Particulate Filter) and so on. There have even been instances of an oil distributor selling recycled oil to their dealers, only for the dealers to discover that the engines were starting to burn and consume more oil! The base stock and additive pack were not good enough, and the oil deteriorated very quickly to the degree that the oil bypassed the piston rings and the engines began to consume it.

If you are paying for a service, repair work, or a complete overhaul of the transmission or engine in your vehicle, you are quite in your right to enquire about the fluids being used and request high-quality ones. When paying substantial money for a repair, it makes sense to use OE quality as an absolute minimum. If your vehicle is modified and the engine produces more horsepower, then it is advisable to use oils that exceed the manufacturer’s specifications or at least change them more regularly.

1024

Carbon Cleaning

Fuel & Carbon Cleaners – What Happens to the Carbon?

March 10, 2015 Andy 7 Comments

Frequently we are asked about fuel-based carbon cleaners. Specifically, what happens to carbon deposits that are removed through the use of fuel cleaners, and can these cleaners damage an engine?

Let’s begin by discussing the first part of that question.

Within the fuel system, you’ll seldom find carbon itself. You will likely discover sludge, gum, varnish, debris, and similar deposits. The fuel filter captures the larger deposits. These and other deposits that have found their way through the fuel system usually are dissolved and dispersed in a controlled and manageable way using dispersal-based detergents. That’s why it is important to use additives at the recommended dosage so that deposit removal is completed in a controlled manner. High-strength fuel system cleaners that carry out this process typically contain a lubricant to ensure the entire system is lubricated during the cleaning procedure. This too, minimizes the risk of any issues.

Most actual carbon formation occurs in the combustion chamber and post-combustion areas. This includes the turbo’s hot side, intake, inlet valves, EGR, catalytic convertor, DPF, and the remainder of the exhaust tract. The reason why carbon remains is that there is insufficient heat to burn it off. Chemically, a liquid hydrocarbon fuel – such as gasoline or diesel – is very similar to the solidified fuel (carbon) it creates. The difference is that a higher temperature must be reached to ignite and burn solid carbons because the flash point has changed.

High-quality fuel detergents, combined with fuel catalyst technology, reduce the threshold temperature at which the carbons can burn, enabling natural engine processes and inherent heat to gradually “burn off” the deposits. This is undoubtedly the case for combustion chamber deposits.

Sometimes there also is a degree of active cleaning from any cleaning chemistry that can survive the combustion process and thus is still active post combustion. However, as described above, most carbon is removed by reducing the temperature at which it can burn.

It is important to note that there also is a natural cleaning mechanism. When the combustion process is of sufficient quality – generally through an efficient fuel system (no injector deposits), good fuel quality (more often than not, only achieved with fuel conditioners), and an engine that is up to full operating temperature – engines are designed to self-manage carbon build-up. The clean(ish) gases will naturally remove carbons to maintain a respectable level.

The issue arises when this equilibrium is broken, and more carbons are deposited than can be naturally removed. This could be due to a flawed engine design, poor fuel quality, fuel system deposits, driving style, failure to let the engine reach the proper temperature, etc., or a combination of these.

This is why catalyst technology is so vital in carbon cleaning and for keeping a system clean. When a catalyst is added to the fuel, it improves the combustion quality to such a degree that it reduces the amount of hydrocarbons created, particularly when the engine is cold. These cleaner gases then work together with the active work the catalyst is doing to reduce the temperature at which these deposits can burn and be removed.

Essentially, a high-end fuel cleaner and carbon remover provide an environment where the combustion quality is much better, and the exhaust gasses are much cleaner. The cleaner exhaust gasses will naturally scavenge and remove carbons from the combustion and the post-combustion areas. The caveat is that this process requires heat. The catalyst will reduce the temperature at which the carbons can be removed and burned off, but it also needs heat.

This is why it is tough for such chemistries to clean the EGR system. The problem is that an EGR and intake are designed to cool recirculating exhaust gasses. Doing so reduces the efficacy of any post-combustion cleaner or chemistry. Unfortunately, this also applies to the rear of the intake valves of direct poor injection engines. Those two areas are challenging to clean because the gasses going through are cooled.

Also, it is difficult to remove existing deposits in these areas. However, by using a high-quality conditioner with the fuel catalyst in both diesel and petrol applications, you’ll at least give the engine and emission control components a much easier life. This is because the engine and emissions systems will have fewer carbons to manage. This results in fewer deposits and hopefully removes the need to use high-strength cleaners or invasive measures to remove carbons manually.

What about the safety of cleaners and the risk of the fuel system or engine damage?

Providing products are used as per the instructions, the risk of any damage is incredibly low. The few rare cases of alleged damage we have witnessed weren’t caused by a product. The product just revealed or exacerbated an underlying mechanical issue with the fuel system. Still, this is incredibly rare.

Furthermore, manufacturers err on the side of caution, so even if a product is used aggressively or improperly, it is still likely to be safe to use up until a certain point.

To summarise, fuel system deposits are generally dissolved, dispersed, and combusted naturally. Carbon is usually combusted through heat and an added fuel-borne catalyst. These processes are proven safe when used correctly and responsibly.

1847

Fleet & Commercial Solutions, Fuel Addtives, Fuel Saving

MPG – Negative vs Positive Gain ™

February 12, 2015 Andy 4 Comments

When examining the field of products, services, and techniques that promise to increase MPG, you find a confusing minefield, at best. There are chronic skeptics on one side, loyal devotees on the other, and indifferent observers in between. Unfortunately, this has come from a long history of ignorance and misleading advertising. The dilemma for most is “who is right and wrong?”

Two other main questions also might come to mind:

1. How do you know if the advertised MPG increase will be achieved?

2. Why are there such inconsistencies regarding product results, ranging from spectacular to absolute zero? Why such a significant variance?

When we service fleets, we combine our knowledge and experience to simplify the process for operators. Firstly, let us explain the type of gains available and the results you can expect to achieve. To best explain this, we would like to introduce you to the concept of Negative versus Positive MPG gain.

Negative Gain is the process of restoring engine economy and efficiency back to factory levels, or more accurately, how it was when it left the manufacturer, except with an engine that is now run-in. These are not the factory-published figures regarding performance, but moreover, the actual performance that is possible from an engine that is run-in, deposit-free, and operating at full efficiency in real-life conditions. This is engine efficiency restoration.

Positive Gain is the process of improving the standard MPG or performance of an engine that is deposit-free and running efficiently on standard pump fuel and lubricants, as recommended by the manufacturer. This is engine efficiency enhancement.

Virtually all fuel and engine additives suppliers claiming 10%, 15%, or 20%-plus improvements in MPG rely heavily on the Negative Gain factor. The increased economy claims are based on the assumption that the fuel system has accumulated deposits and that the engine is experiencing a reduction in fuel economy and performance as a result.

This is very important. The reason for such inconsistency is that there are many variables in play. One vehicle may have a considerable reduction in fuel economy or performance (due to fuel system or engine deposits), while another has virtually none. Also, different engine designs respond to deposits in varying ways. It is really that simple. The majority of gain you tend to see, however great or small, is negative gain or performance and efficiency restoration. Unfortunately, negative gain or efficiency restoration potential is challenging to predict.

This part of fuel and oil additive marketing is particularly troubling, as it can lead to unrealistic customer expectations. We believe it is misleading to make claims about MPG increases on the assumption that the fuel system and/or engine have accumulated substantial deposits. Of course, such claims are always caveated with increases “up to” a certain amount.

So, how does the negative and positive gain theory work?

Negative Gain (Economy & Performance Restoration)

Assuming that an engine’s mechanical condition is good and that all its electrical components and respective sensors are operating correctly, there are three ways to restore lost MPG.

1. Fuel system cleaning. This involves using a professional cleaner to remove any benign or debilitating deposits from the fuel system. It also includes any remedial work to remove biological or non-biological contamination within the fuel or fuel system. This restores the correct fuel flow and atomization of fuel into the combustion chamber.

2. Carbon Removal. This is the process of using professional cleaners and combustion modification technology to remove carbon build-up from the combustion and post-combustion areas of the engine. These include emission control components like the exhaust gas recirculation system (EGR), diesel particulate filter (DPF), etc.

3. Compression restoration. This is the process of restoring any lost engine compression by using a professional engine oil flush or lubricant-based cleanser to remove deposits from the pistons, piston rings, and cylinder bores.

Depending on which of the above applies and assuming the correct products and processes are employed, virtually any engine can be restored to optimum efficiency and performance. The only notable exceptions are when an engine or any of its periphery parts are mechanically worn, degraded, or failed. Even then, various technologies and processes exist to restore minor wear.

Positive Gain (Economy & Performance Enhancement)

Again, assuming all is equal and an engine is in good working order, there are five ways to increase efficiency and performance above the standard factory figures.

1. Friction reduction. This involves using specialist products and techniques to reduce friction to levels lower than that available from conventional oils and lubricants. Other benefits can include greater protection against reduced component wear and lower maintenance costs. This can be applied to engines, transmissions, differentials, wheel bearings, and so on.

2. Fuel combustion modification. This includes the continuous use of professional chemistries to improve the combustion efficiency of the fuel, resulting in greater fuel economy, performance, and a reduction in exhaust emissions. Such products can also prevent fuel degradation, protect the fuel system, and control deposit build-up, thus removing any future need to use products to restore lost performance.

3. Engine retuning (software). This is the process of altering the engine control unit (ECU) or how the ECU manages fuel injection, ignition timing, and other engine control parameters. This can provide more efficient power and torque delivery throughout the rev range, reducing fuel usage.

4. Engine retuning (physical). This includes physically modifying engine components such as adjusting intake manifold air-flow dynamics, altering the exhaust system or DPF, and so on.

5. Other modifications. Making other pragmatic modifications that are widely known, such as optimising tyre pressures, improving aerodynamics, reducing unwanted weight, altering driving style, etc., can also improve efficiency.

Positive gain can manifest itself as additional performance (as measured in horsepower and torque), an increase in fuel efficiency, or a combination of both.

Testing Protocols:

We specialise in the development of bespoke MPG testing protocols. With any test, whether a single consumer vehicle or a fleet of heavy goods vehicles, it is important to set objectives and correctly plan how to achieve and measure them.

Below are some contributory risks and variables that must be considered when developing a comprehensive test plan. Please note that we were advised against revealing this information as it would undoubtedly be copied and reused by other companies selling fuel-saving additives or devices. However, if it helps to restore some integrity to the field of MPG testing, then we believe this benefits us all. Whether you sell fuel-saving technology or are looking to test and buy fuel-saving technology, let’s please restore some integrity to this field.

	Risk	Mitigation / Containment
1	Length of the test is too short.	It goes without saying that the more test data available, the easier it is to discern positive, neutral, or negative results.
2	Lack of availability of historical test data and seasonal differences.	It is of paramount importance that historic baseline data is available. If not, this should be captured first. Also, take into consideration the seasonal variations. For example, if you are conducting a three-month test between April and June, it would be advantageous to have baseline data for the same months in the previous year and the months of January to March immediately before the test. You would be surprised with the variance of data between seasons.
3	Inaccurate MPG monitoring techniques.	The most common are on-board monitoring and manual calculations. Where possible, use both monitoring techniques. Telematics that includes average speed is also extremely valuable as it will help validate or invalidate MPG figures. If the average speed for a vehicle increases during a particular month, then the MPG would be expected to increase by default and vice versa.
4	Varying climatic conditions.	Weather can profoundly affect results, and not just temperatures. Wind can affect drag, rain can affect grip, etc. A combination of controlled and real-life tests can mitigate this.
5	Varying traffic, routes, and loads.	Variances in routes, traffic, and loads can affect results. Choosing the most consistent routes with consistent loads in low traffic periods and a combination of controlled and real-life testing is the best bet, albeit not always possible.
6	Driver inconsistency.	Where possible, the same driver should be used. Otherwise any change of driver must be factored into the test results.
7	Varying vehicle history and condition.	Even vehicles of the same type and engine are different and can respond differently. Pick both a poor performing and good performing vehicle. It is important to understand that results are only applicable and valid to that particular vehicle/engine combination.
8	Fuel inconsistency.	Different brands and types of fuel (including seasonable blends) can affect results. Where possible, the exact same fuel should be used throughout the test and during any pretesting.
9	Poor accuracy with administering treatments.	How treatments are administered is important. For example, treating the fuel at bunkered storage mitigates the risk of incorrectly applied ratios when testing fuel additives. Automated dispensing systems are also an alternative.
10	Driver awareness affects results.	Blind testing always provides the most accurate results unless trust in the driver is assured. If the driver is aware, then also make them aware during the pretesting (baseline) stage. This can ensure that the driver will not significantly change the driving style during testing.
11	Fuel or additives theft.	Unfortunately, this does occur. There are ways to identify and mitigate this risk. However, it would not be appropriate to list them here.
12	Lack of test data.	What to test (mpg, power, torque, emissions, oil quality, wear, etc.) is fundamental to understanding the benefits of any given product(s). Simply, the more data, the greater the confidence in the decision-making process.

There are other minor factors that we won‘t go into as they apply more to controlled testing, such as the effects of ambient temperature on fuel density and so on. However, the above twelve points will serve you well.

We make our clients fully aware of the common pitfalls and underhand techniques that some companies use. For example, a common tactic is to advise the client to notify the driver that a test is being conducted. The driver is then aware that his driving is likely to be scrutinised and, as a result, drives more cautiously and ” efficiently. ” The client then witnesses a tangible increase that has little to do with the prescribed treatments but is instead from an improvement in driving style by the driver.

Another tactic is to convince the client to pick their worst-performing vehicle for testing. This, of course, increases the probability of more outstanding results. The client then becomes blinded by negative gain results that cannot be reproduced on their other, better-performing vehicles. Ideally, you should test average-performing vehicles or the worst and best-performing ones in the fleet.

The key is to produce a test protocol that mitigates or eliminates as many variables as possible. This will help ensure accurate test data, which, in turn, enables the client to make informed decisions as to the actual ROI on particular treatments or processes.

If you require more information or a no-obligation consultation on MPG reduction or engine cleaning, please don’t hesitate to contact us.

Andy Archer

Energy and Maintenance Saving Consultant

1564

Misfuelling Devices

Factory Misfuelling Protection Devices

February 12, 2015 Andy Leave a comment

Some diesel vehicles, particularly Ford’s and BMW’s, come equipped with misfuelling prevention devices. The purpose is straightforward – to prevent the user from accidentally adding petrol to a diesel fuel tank.

Most devices work through a mechanism that only permits the exact diameter of a standard diesel pump nozzle to penetrate the filler neck. Any smaller diameter nozzle, such as that of a petrol pump nozzle, filler funnel or similar, will not enable the mechanism to open the filler flap.

The problem is that the user is then unable to administer fuel additives or fill up from a jerry can in the unfortunate event that they run out of fuel. Well, no need to panic. Most vehicles with anti-petrol filler mechanisms usually have a funnel or insert stored in the boot, usually near the spare wheel. If not, then a suitable funnel/filler insert can be obtained online or from your local dealer.

1683

Carbon Cleaning, Fuel System Cleaning

Engine & Fuel System Cleaning Machines – A Review

November 14, 2014 Andy 12 Comments

I am regularly asked to comment on a particular engine (fuel system) cleaning system once featured on a popular automotive TV show.

Does the product work? Well, actually, yes, it does. It will clean the fuel system and help remove combustion (carbon) deposits. However, I am not convinced it is anything new or innovative except how it has been presented and released to the market. The product design, presentation, and choice of celebrity endorsement are pure genius. I don’t think they could have done it better or chosen a more suitable candidate to endorse the product. I am a fan of the unsaid celebrity, by the way.

Cleaning equipment that you connect directly to fuel systems of both petrol and diesel engines has been around for more than two decades. It was popular in the 1990s and at the start of this century. But its popularity declined for the simple reason that in-tank fuel cleaning technology had improved to the degree that such apparatus was no longer necessary, except under certain circumstances (i.e., engine running very poorly). Even rapid carbon removal (combustion and post-combustion, DPF, etc.) is now achievable through fuel-based chemistry. Patented fuel-borne catalyst technology for removing post-combustion carbon has been in use for some time and is very successful. As a result, this type of fuel system servicing became an unnecessary gimmick, in my opinion. The creators of this cleaning device made it sexy and credible again, and to a degree, a little more affordable, with a clean costing around £80, rather than the £100+ that was charged more than a decade ago.

In my view, the type and quality of cleaning chemistry are significantly more important than the method of administration. Adding a product directly to the fuel system—no matter who the manufacturer—might look impressive, but in most cases, it is not necessary.

And this is my point; adding a high-end fuel cleaning product to the fuel system can clean just as well.

Arguably, a high-end fuel cleaning product can, in some cases, work even better if you consider that it can clean the entire fuel system from the tank onwards, including the fuel filter. It is often the case that companies offering both types of cleaning products use the same chemistry, except that the direct-to-fuel rail method product is already mixed in with a base fuel.

Where rapid cleaning is required, many professional garages will add a full-strength fuel cleaner to an almost empty tank (i.e. 10 litres) and then let the engine idle for 15-30 minutes. This can provide an intense and rapid clean with minimal risk because the engine is not under any load.

Of course, supporters of these products will point out that there are plenty of good reviews of these systems. That is very true. But similarly, there are many good reviews for high-end, in-tank fuel system cleaning products, too. I could bore you all day with the many hundreds we have accumulated, with some customers reporting a profound change in engine running and performance. And they aren’t wrong. If there are fuel system and carbon deposits, both methods will produce tangible results that the customer will feel. If there are no discernible deposits, then neither method will make a difference.

Another question is, “Will this device remove deposits from the rear of intake valves on direct injection engines, such as those in BMWs, Audis, Minis, etc.?” No, but neither will in-tank cleaners. Both methods might remove a few of these deposits, but not enough to consider them successful. This is the new challenge manufacturers and aftermarket solution providers face – creating effective intake valve cleaning by administering detergents directly through the air inlet. But this is a conversation for another day.

Conclusion: It works, but are you getting more for your money than you would with a much less costly, high-strength professional in-tank cleaner? My short answer? No.

1840

Waterless Engine Coolant

Potential Issues with Waterless Engine Coolants

August 1, 2014 Andy 6 Comments

Below is an interesting US-based article I received a short while ago. This is not intended to bash any particular manufacturer of waterless coolants; it is just a challenge to the technology used.

“Many concerns have been raised to us in recent months regarding the effectiveness of Waterless coolants and the inherent dangers they may possess. We have spent some time researching the product and would like to make all our customers aware of our findings.

Waterless products are 100% glycol, some are 100% propylene glycol, and others are a mix of propylene glycol and ethylene glycol. They are slippery when spilled or leaked onto the tarmac. Assuming a baseline friction co-efficient reference of 1.00 for dry pavement, the friction coefficient of water is 0.65. The friction coefficient of Waterless products is 0.16, four times less than water. Some race circuits in America are now prohibiting the use of engine coolant that contains ANY glycol due to this fact.

The other and more pressing reason that Waterless products are prohibited at race circuits is that they are flammable. With flash points in the range of 110-130°C if the Waterless coolant were released at or above the flash point, it could ignite. Coolant temperatures can be observed in this range during actual operating conditions, making this a real risk. Reports have also been made of damage caused by glycol coolant fuelled fires, in some instances, destroying whole cars and resulting in thousands of pounds worth of damage.

The NHRA rule change regarding glycol coolants was the result of a terrible fire where the competitor was using Waterless coolant in his car. The engine pushed a head gasket and the coolant caught fire which came under the seat resulting in a cockpit fire. Glycol coolants are now prohibited in the NHRA. In another case the Motorsport South Africa ASN prohibited the use of glycol on safety grounds “In the case of both cars and motorcycles, the use of glycol-based coolant additives is prohibited.”

In addition, the operational downside is the decreased ability to transfer heat compared to water based coolants. Waterless coolant should never be advised in applications where heat issues are apparent, Waterless coolants will only compound this problem as they lack the necessary heat transfer properties to provide a solution.

Although the product is a very good corrosion inhibitor, it will not adequately protect an engine when overheating. The Waterless coolants cannot transfer heat as efficiently as water, thus causing an engine to run hotter. The engine will continue to run hot until a critical component fails as the boiling point is so high.

To summarize:

Engines can run 45-60°C hotter (at the cylinder heads) with Waterless products.

Stabilized coolant temps are increased by 15-25°C.

Specific heat capacity of Waterless products ranges from 0.64 to 0.68, or about half that of water.

Engine octane requirement is increased by 5-7 numbers reducing engine horsepower by 4-5%.

Viscosity is 3-4 times higher than what OEM water pumps are rated to accommodate.

Coolant flow rate through radiator tubes is reduced by 20-25% due to the higher viscosity.

Race circuits are starting to prohibit waterless products because they are flammable and cause a slippery surface hazard when leaked.

When speaking to a classic car specialist recently the subject of Waterless coolants was brought up.A Waterless coolant manufacturer had given them product sponsorship ahead of classic Le Mans 2012, in FP1 the car stopped on track with smoke billowing out of bonnet. On closer inspection the coolant had plasticized and warped the head, the coolant then passed through the head gasket hydraulic locking cylinder one. The damaged cause was very costly and ended the team’s weekend early, it is not a product they would recommend or use again.”

We sold a waterless coolant for a short while but stopped over a year ago. We never encountered any issues although it sounds like potential issues are more “race” related. However, I thought we would be remiss if we did not share this information with you as it opens a valuable debate into the safety and efficacy of such technologies versus conventional water based cooling products.

As FuelTechExperts is promoted as an unbiased source of information it is only fair that Evans have the opportunity to respond.

Response from Evans below:

“Thank you for the opportunity to relay our side of the debate here.

Glycol is slippery. As I said to the technical director in the American Flat Track Series, any fluid is slippery on the track. What’s important is keeping the fluid off the track in the first place. Our coolant does not build vapor pressure, so it doesn’t boil out when it gets hot like antifreeze or water. Our coolant is legal in flat track and some road race motorcycles series. I road raced motorcycles with waterless coolant for 15 years without incident. I wouldn’t ask anyone to do something that I haven’t done myself.

All glycol based coolants are combustible, this includes water-based antifreeze. The “flash point” is the same for waterless and water-based coolants, go ahead and google “gylycol fire”. Flash point does not mean that it will spontaneously ignite, there must be a flame source present. The auto-ignition temperature is significantly higher, somewhere up above 700F. Again, this behavior is common with water-based antifreeze as well.

The heat transfer of waterless coolant is a little less than with water-based antifreeze just as water is a better conductor of heat than antifreeze. A cooling system is “air side limited”, however, which means that the heat transfer between metal and liquid is insignificant compared to the heat transfer between metal and air at the radiator. The radiator efficiency is based on the temperature difference between the radiator metal and the air temperature. The greater that temperature difference, the better the transfer efficiency. Runaway temperatures are a problem with water-based antifreeze, not waterless coolant because when the water boils to vapor inside the engine virtually all cooling capacity is lost. The metal temperatures will spike by hundreds of degrees creating the detonation-causing hot spots and head warping that is associated with overheating. If our coolant temperatures rise above normal, it doesn’t vaporize and the liquid to metal contact is not lost. With a higher coolant temperature, the radiator efficiency improves because of the larger difference between metal and air temperatures; the system will reach equilibrium rather than spiking.

Octane is needed to delay detonation of the fuel mixture. A lower octane can actually be used with our coolant because hot spots are not formed.

The viscosity of our coolant at operating temperature is very close to that of antifreeze, again, not an issue.

Like radial tires and disc brakes, not everybody will accept a new technology at the start; we are offering an advancement in engine cooling and everyone needs to make their own decisions.

John Light -Evans Powersports Coolant Director”

1238

TFSI Direct Injection Carbon

Turbo Fuel Stratified Injection (TFSI) & Direct Port Injection Carbon Build-up Problem

July 17, 2014 Andy 22 Comments

The Problem of Turbo Fuel Stratified Injection (TFSI) & Direct Port Injection Carbon Buildup

The problem with carbon buildup on the back face and stem area of intake valves in direct fuel injection petrol engines is not news. Fortunately, a significant breakthrough has occurred recently on the buildup issue, and the exact cause of the problem has been isolated.

Carbon buildup in direct fuel injection engines running on petrol became prominent in 2007 and 2008 when the engine warning codes and Malfunction Indicator Lights (MIL) began to light up in many vehicles with direct injection engines, including the BMW Mini, and those made by Audi and Volkswagen.

The presence of excessive carbon buildup has generally been attributed to the direct port injection design. This design enables a more complete and efficient combustion process because fuel is injected directly into the combustion chamber rather than behind the inlet valve, which is where it is injected in conventional port injection designs. However, with this design any cleaning capability of the fuel — or more importantly, the fuel additives — is non-existent in the inlet tract because the liquid fuel never comes into contact with the back of the intake valves. The cleaning effect on the front of the valves on the combustion chamber side, on the combustion chamber surfaces, and the exhaust valves is easily achieved as a consequence of the clean-burning characteristics of high-quality fuel and/or additives. But the downstream surfaces of the inlet valves are left untouched, and therefore accumulate deposits. The volume of these deposits eventually alters the air-flow dynamics within the inlet tract, which in turn inhibits airflow and ultimately reduces volumetric efficiency considerably.

The impact of this is more noticeable on normally aspirated engines as they are less able to overcome air-flow restrictions, whereas forced induction engines can overcome minor restrictions as air is “forced” into the combustion chamber under pressure.

The images below illustrate the direct fuel injection and port fuel injection design. You will notice on the port injection design that fuel is injected behind the inlet valve, and the mixture of fuel and air is then drawn into the combustion chamber as the valve opens. This is not as efficient as a direct injection design but helps prevent deposit buildup on the intake valves.

So what has changed?

A major breakthrough recently on the buildup issue has led to the exact cause of the problem being isolated. The port injection design is actually not the cause but merely the reason why the issue cannot be controlled and managed through normal fuel-derived cleaning processes.

It is now understood why even the most advanced post-combustion cleaning fuel additives or solvent-based cleaning through the fuel /air intake tract have had little effect. Furthermore, it also is understood why rerouting the byproduct from the crankcase breather into segregated catch cans or using water/methanol injection are of limited value when it comes to reducing carbonaceous buildup in the inlet port and inlet valve surfaces.

Post combustion cleaning additives, solvent-based intake cleaning, and water/methanol injection are not effective because the carbon species responsible for the buildup are predominantly from lube oil and produce active but very dense layers of carbons. In some cases even grit blasting techniques have failed to remove the buildup because of the integrity, toughness, and adherence of the deposits. In contrast to these deposits from lube oil, ones resulting from the decomposition of fuel tend to produce a satin black buildup that can be scraped off easily with a finger nail. This type of deposit can be removed with fuel-borne additive technology. However, the deposits formed from the decomposition of lubricating oils during engine operation have been found far more difficult to remove. This deposition and growth of carbonaceous debris has been demonstrated on a test engine with inspection ports positioned in the inlet tract.

In the pictures below you will notice the solidity of the lube-based buildup on the inlet valve of an Audi RS4 (4.2 V8 TFSI) versus the fuel-only carbon buildup on an EGR valve in a different vehicle. The carbon on the latter is easily removed either manually or via fuel additive technology that is still active post combustion.

Audi RS4 Inlet Valve Carbon Buildup

EGR Valve Part Cleaned

Oil on valve stems – It should be noted that the presence of lubricating oil in this location is normal. Having a controlled amount of oil there keeps the valve stems lubricated. One reason why NA engines tend to suffer more from inlet-valve deposits is simply that in the created vacuum, the oil from the valve stems is more difficult to “control” because it is sucked through by the pressure differential existing between inlet manifold and the atmosphere. In comparison, forced-induction engines (turbo or supercharged) generally operate with the intake manifold under positive pressure so less oil is pulled through the seals.

So if the small amount of oil bypassing the valve stem seals is normal, and indeed required, then why is there an excessive buildup of deposits on the valves? One hypothesis is that:

The oil is being broken down by the catalytic (reacting) action of the materials used to manufacture or coat the valve stems. In particular, nickel and chrome alloys. This pyrolytic decomposition is widely recognised in the industrial power generation sector where hydrocarbons are in contact with superalloys used in the construction of combustors, nozzle guide vanes, and exhaust components.

In layman’s terms, this means the materials used to manufacture and harden the valves are reacting with the lubricating oil and creating an aggressive bond between the lube and the valves!

Although this hypothesis seeks to explain the mechanism behind the formation of these carbonaceous deposits, there are still many challenges ahead. As carbon is the constituent part of all lubricating oils and fuels and each of these is fundamentally required by engines in their present form, a method of reducing or eliminating carbon buildup must be sought.

Once oil has initially decomposed and formed a bonded carbon deposit with the valves, it remains chemically active. This allows further carbons — whether from engine oil or recirculating fuel emissions – to adhere to the existing mass with ease.

Some manufactures have incorporated a more complicated fuel system with a combined port/direct port engine design to retain the benefits of direct port injection whilst injecting some fuel behind the valves to help keep them clean. However, for existing direct port engine designs there are few viable options. One can change the valve material and/or use a coating that doesn’t catalyse with carbons or enable the adherence of carbon, or introduce an additive pack that can inhibit carbon formation.

Valves have to work very hard and current valve materials are chosen for their toughness and durability. Any replacement material and/or coating would have to at least share or improve upon these properties. There are proposals in the area of material and surface coating choice but we are not at liberty to share them at this stage.

Other theories consider that at certain engine operating conditions there is a small amount of backwash as the early injection of fuel occurs whilst the inlet valve is still open. The contribution of EGR also needs to be considered. For compression-ignition engines – diesels – the heavy contamination of inlet tracts with a dense, but greasy, carbon-based deposit is well known. There are many EGR deletion methods that focus on the prevention of this deposit buildup, which as in the case of their petrol-fuelled counterparts, can seriously impede the flow of inlet air to the combustion chamber.

Operating temperatures of engines have tended to increase with commensurate increases in combustion chamber parts. And heat soaking on shutdown, as well as extensive idling periods, have been shown to affect the amount of buildup on upper cylinder parts and valve gear.

Regardless, the issue of removing existing deposits does not go away. The use of more advanced polar solvents will be investigated but this process is still constrained by the hardness of the carbon buildup, as well as the risk of unmanageable chunks of carbon being dislodged and damaging valves or cylinder bores during engine operation. Managing the gradual fluidising of deposits so that they can be safely consumed during combustion is a significant challenge.

There is some data to suggest that the use of certain oil additives or group IV and above base stock oils (pure PAO, esters, etc.) reduces the speed of buildup. However, this is not fully substantiated as back-to-back tests were not conducted on the exact same vehicle. The tests show visual buildup compared to other similar vehicles of similar mileage that are not using additives or group IV and above engine oils. Furthermore, some of the PAO-derived oils are more readily broken down by catalytic action and tend to have better high-temperature resistance to degradation, thus keeping a fluid film on the valve stems where decomposition may occur. One area of interest is the use of mineral oils containing carbon fluidising additives as found in many two-stroke engine oils; however these compositions generally do not meet the lubrication specifications required by modern engines.

Archoil® has been using proprietary esters and fluidising technology for some time and we have initiated further tests relating to this technology and direct port engines. We will keep you posted as soon as we have more information.

UPDATE MAY 2017

Archoil has released a fuel conditioner (AR6900-P MAX) that specifically addresses this issue. By delivering a regular dose of polyetheramine and proprietary combustion catalyst, much of the carbon matter from engine oil or that created through the combustion process is neutralised.

Due to the concerns raised in the article – 1. Stubborn composition of the existing carbon build-up and 2. Minimal effect of detergent and fuel borne catalyst technologies in areas of insufficient heat, AR6900-P MAX will be limited in its ability to remove existing build-up. However, it will help neutralise and inhibit further deposit build-up.

UPDATE JAN 2024

Oilsyn has released Petrol Power DNA, using their PEATech cleaning technology. This is a combination of cleaning functions, amines, polyetheramines, and more. An independent titration test showed that a single dose (50ml per 50L of fuel) tested at over 90 points!

This is the highest-strength cleaner on the market by some margin. At 90 points, a single 50ml dose from the 1L bottle is actually stronger than most single-use cleaning treatments. Therefore, 1L of Petrol Power DNA is the equivalent of 20+ single-use cleaners.

If Petrol Power DNA doesn’t help neutralize carbon deposits then nothing will.

1548

Cetane Boosters & 2-EHN

Cetane Booster – What is the Best?

May 2, 2014 Andy 19 Comments

The overall quality of diesel fuel is dependent on several factors. These include BTU value, viscosity, pour flow point, aromatic and paraffinic content, and resistance to contaminant buildup such as water and bacteria. A diesel fuel’s quality also is very dependent on its cetane number.

The cetane number (CN) is an index of the ignition point or combustion quality of diesel fuel and is measured using an ASTM D613 test. Standard European BS EN590 diesel from the pump typically has a minimum cetane number of around 51, with premium pump diesel a little higher. Depending on engine design, driving conditions, and so on, the optimum cetane value for most vehicles is around the mid to high 50s. Any value greater than 60 will not achieve any additional benefits and, in most cases, will alter ignition timing to the degree that power is lost.

Matching cetane to the engine is essential to maximize the engine’s performance. Biodiesel fuels in particular, especially homemade brews, usually start with a much lower cetane number, so cetane improvement for these fuels is essential.

A fuel with too low of a cetane number for a particular engine will result in reduced cold-start ability, rough running, excess engine noise/vibration, and reduced combustion quality. This leads to reduced performance, excess emissions, and carbon buildup throughout the engine and emission system components (intake, EGR, DPF, etc.)

A higher cetane fuel that is a proper match for the engine will reduce ignition delay, improve overall combustion quality, liberate more BTU (energy) from the fuel, and improve performance and MPG. It also will reduce engine noise, deposit buildup, and exhaust emissions.

What should I look for in a cetane booster?

Contrary to some propaganda, alkyl nitrates still offer the most significant improvement in cetane number, with measured increases of up to eight points. When it comes to alkyl nitrates, 2-Ethylhexyl nitrate (2-EHN) is the most popular and most respected. It offers a more consistent ignition quality while reducing unwanted and adverse combustion conditions.

Fuel additive manufacturers recognize the benefits of boosting the cetane number and using 2-EHN so much now that most offer cetane improvers. The question in this case is, what are you getting for your money?

From a close examination, it appears many cetane boosters contain useless fillers. Most manufacturers still insist on the single bottle per tank philosophy to maximize profits. Some 200-300ml bottles that treat a single tank of fuel have as little as 20% active ingredients. This is lucrative for the manufacturer but not a good value for the consumer. Therefore, it is important to understand what you are getting for your money.

The optimum amount of 2-EHN is around 20-100ml per tank of fuel, depending on the engine and base cetane level. As 2-EHN can reduce lubricity, a lubricant must be blended in. To ensure you are getting the best value, ensure the product contains 2-EHN as its base, and a reasonable proportion of the remainder contains beneficial ingredients, such as lubricant, detergent, etc.

UPDATED AUG 2022 – So what do we recommend and why?

Active cetane improvers are essentially a form of fuel modification, or more accurately, combustion modification. However, when combined with the correct fuel catalyst technology and lubricity additives, they can turn the most mediocre pump fuels and biodiesels into super diesel that will outperform the best premium pump fuels.

Two products to note:

Oilsyn® Diesel Race DNA, Diesel Power DNA or Archoil® AR6900-D MAX. Rather than introduce another diluted cetane booster, they released a concentrated chemistry product containing 100% active ingredients. They deliver optimum increases in cetane while being able to treat multiple tanks of fuel rather than just one.

Diesel Race DNA contains the highest levels of 2-EHN of any compound diesel conditioner and the highest performing diesel lubricant on the market at this time, with an HFRR test of below 180! AR6900-D is a careful balance of cetane improver, detergent, lubricant and combustion catalyst. Both protect the entire fuel system against the harmful effects of low lubricity and low sulphur fuels. This results in an optimum combustion condition, comprehensive fuel system protection and cleaning, increased performance, and reduction in harmful exhaust emissions.

Summary:

For the ultimate performance and protection – use Oilsyn Diesel Race DNA.

For an all-around product that increases cetane, cleans and protects – use Oilsyn Diesel Power DNA or Archoil AR6900-D

Either of the above works out cheaper per tank than upgrading to premium diesel at the pump.

1730

Contact us

Find us on:

Newsletter