Quick answer
A BMW 335i (gas turbo inline-six) sees about 20–25 mpg combined, while the 335d (diesel) can push upper 20s to low-30s if driven gently.
Detailed answer
The BMW 335 lineup offers robust power. The 335i’s twin-turbo inline-six can average 20–25 mpg combined, which drops if you exploit its performance. Meanwhile, the 335d’s diesel torque and efficiency let you see 28–32 mpg combined—some owners achieving mid-30s on long, steady highway stretches.
Both rely on premium fuel or high-quality diesel. Maintenance includes spark or glow plug checks, synthetic oil, and ensuring turbo systems stay healthy. Aggressive city driving or higher speeds will lower mpg. Ultimately, if you want a spirited BMW with moderate consumption, the 335d edges out in efficiency, whereas the 335i caters to those preferring a classic gas turbo feel.
