Should the BMW 5 Series use 95 or 98 octane gasoline?
2 Answers
The BMW 5 Series has a relatively high compression ratio, so it is recommended to use 95 octane unleaded gasoline. Using 98 octane is even better, but 98 octane gasoline is not available at most gas stations in most cities across the country—only a few gas stations in major cities like Beijing, Shanghai, and Guangzhou supply it. Owners can check the recommended gasoline grade on the back of the fuel tank cap, which indicates 95 or higher unleaded gasoline, meaning both 95 and 98 octane can be used. The BMW 5 Series engine model is the N20B20. After the inline 6-cylinder engine was turbocharged, BMW began developing small-displacement turbocharged engines to gradually replace the classic N52. The 4-cylinder engine, numbered N20, is currently installed in the X1, Z4, and the new 3 Series.
As a BMW 5 Series owner who's driven it for nearly three years, I've actually researched this issue thoroughly. The manufacturer's manual clearly states that 95-octane or higher gasoline is recommended, so 95-octane is definitely suitable. While 98-octane is significantly more expensive, it offers better anti-knock performance, making it ideal for frequent high-speed driving with elevated RPMs. For regular city commuting, 95-octane is absolutely sufficient. I've personally tested using 98-octane fuel continuously and noticed the engine sound does become smoother with slightly quicker throttle response, but there's no significant change in fuel consumption. Remember not to mix different octane ratings when refueling - there's a recommendation sticker inside the fuel filler flap, just take a look if unsure. Long-term use of 95-octane fully complies with warranty requirements, so there's no need to spend extra.
