2007 BMW X5 Owner's Manual - Page 215

Fuel specifications Do not use leaded gasoline, otherwise damage to the catalytic converter will result. Do not use E85, i.e. fuel that consists of 85% ethanol, or Flex Fuel, otherwise permanent damage to the engine and the fuel supply system will result.< Failure to comply with these recommendations may also result in unscheduled maintenance.< Required fuel Super Premium Gasoline/AKI 91 However, you may also use gasoline with less AKI. The minimum AKI Rating is 87. If you use gasoline with this minimum AKI Rating, the engine may produce knocking sounds when starting at high outside temperatures. This has no affect on the engine life. Do not use gasoline below the specified minimum quality, otherwise engine damage can result.< Field experience has indicated significant differences in fuel quality: volatility, composition, additives, etc., among gasolines offered for sale in the United States and Canada. Fuels containing up to and including 10% ethanol or other oxygenates with up to 2.8% oxygen by weight, that is, 15% MTBE or 3% methanol plus an equivalent amount of co-solvent, will not void the applicable warranties with respect to defects in materials or workmanship. The use of poor-quality fuels may result in drivability, starting and stalling problems especially under certain environmental conditions such as high ambient temperature and high altitude. Should you encounter drivability problems which you suspect could be related to the fuel you are using, we recommend that you respond by switching to a recognized high-quality brand such as gasoline that is advertised as Top Tier Detergent Gasoline. 213 Online Edition for Part no. 01 41 0 012 501 - © 08/06 BMW AG Reference Mobility Communications Entertainment Use high-quality brands Navigation Driving tips This gasoline is highly recommended. Controls At a glance