1998 Lexus ES 300 Owners Manual - Page 195

ENGINE FUEL Fuel type Your vehicle must use only unleaded gasoline. To help prevent gas station mixups, your Lexus has a smaller fuel tank opening. The special nozzle on pumps with unleaded fuel will fit it, but the larger nozzle on pumps with leaded gas will not. At a minimum, the gasoline you use should meet the specifications of ASTM D4814 in the U.S.A. and CGSB 3.5-M93 in Canada. If your engine knocks ...If you detect heavy knocking even when using the recommended fuel, or if you hear steady knocking while holding a steady speed on level roads, consult your Lexus dealer. However, now and then, you may notice light knocking for a short time while accelerating or driving up hills. This is no cause for concern. Gasolines containing detergent additives Lexus recommends use of gasolines that contain detergent additives to avoid build-up of engine deposits. For further details, ask your Lexus dealer or a local gasoline retailer. NOTICE Do not use leaded gasoline. Use of leaded gasoline will cause the three-way catalytic converter/warm up three-way catalytic converter to lose its effectiveness and the emission control system to function improperly. Also, this can increase maintenance costs. Improved gasolines The American Automobile Manufacturers Association (AAMA) has developed a specification of improved gasolines. The AAMA specification offers optimal fuel information for better vehicle performance and better protection of your engine. Lexus recommends the use of gasolines that meet the AAMA specification, if available, for improved drivability and emission control system. Octane rating Select Octane Rating 87 (Research Octane Number 91) or higher. For improved vehicle performance, the use of premium unleaded gasoline with an Octane Rating of 91 (Research Octane Number 96) or higher is recommended. Use of unleaded fuel with an Octane Rating or Research Octane Number lower than stated above will cause persistent heavy knocking. If it is severe, this will lead to engine damage. 195