BMW X3 Owners Manual: Note

General fuel quality

Even fuels that conform to the specifications can be of low quality. This may cause engine problems, for instance poor engine startup behavior, poor handling and/or poor performance. Switch gas stations or use a brand name fuel with a higher octane rating.

Gasoline

For the best fuel efficiency, the gasoline should be sulfur-free or very low in sulfur content.

Fuels that are marked on the gas pump as containing metal must not be used.

Refuel only with unleaded gasoline without metallic additives.

Do not refuel with any leaded gasoline or gasoline with metallic additives, e. g. manganese or iron, as this can cause permanent damage to the catalytic converter and other components.

Fuels with a maximum ethanol content of 10 %, i. e., E10, may be used for refueling.

Ethanol should satisfy the following quality standards:

US: ASTM 4806-xx
CAN: CGSB-3.511-xx
xx: comply with the current standard in each case.

Do not use a fuel with a higher percentage of ethanol

Do not use a fuel with a higher ethanol percentage than recommended or one with other types of alcohol, e.g. M5 to M100; otherwise this could damage the engine and fuel supply system.

Recommended fuel grade BMW recommends AKI 91.

Minimum fuel grade BMW recommends AKI 89.

Minimum fuel grade

Do not use any gasoline below the minimum fuel grade as this may impair engine performance.

If you use gasoline with this minimum AKI Rating, the engine may produce knocking sounds when starting at high outside temperatures.

This has no effect on the engine life.

Fuel quality

The use of poor-quality fuels may result in harmful engine deposits or damage. Additionally, problems relating to drivability, starting and stalling, especially under certain environmental conditions such as high ambient temperature and high altitude, may occur.

Failure to comply with these recommendations may result in the need for unscheduled maintenance.