2007 BMW 7 Series Owner's Manual - Page 201

Fuel specifications Do not use leaded gasoline; otherwise, you will damage the catalytic converter. Do not fill the tank with E85, i.e. fuel consisting of 85Ξ ethanol or flex fuel. Otherwise the engine and fuel supply system will be damaged.< Required fuel Super Premium Gasoline/AKI 91 This gasoline is highly recommended. However, you may also use gasoline with a lower AKI rating. 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 effect on the engine life. Do not use any gasoline below the minimum specified fuel grade. Otherwise the engine could be damaged.< Use high-quality brands 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 Ξ ethanol or other oxygenates with up to 2.8Ξ oxygen by weight, that is, 15 Ξ MTBE or 3Ξ 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 driveability 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. Failure to comply with these recommendations may result in unscheduled maintenance.< 199 Online Edition for Part no. 01 41 0 013 316 - © 02/07 BMW AG Reference Mobility Communications Entertainment Navigation Driving tips Controls At a glance