Quick answer
Cetane fuels are for diesel (fast ignition), while octane fuels are for petrol (knock resistance). They serve different engine types and aren’t interchangeable.
Detailed answer
Cetane relates to diesel’s capacity for compression ignition—higher cetane means a faster, more efficient burn. Octane matters to petrol engines, ensuring the fuel won’t ignite prematurely under compression. Trying to swap the two or mixing them up can be disastrous: diesel engines need rapid self-ignition, whereas petrol engines depend on a spark plug to set off a controlled burn. Put simply, they’re different fuels designed for different combustion styles. Always follow your vehicle’s specific requirements, as misfueling can cause severe engine damage.
