2011 Lexus HS 250h Owners Manual - Page 564

6-1. Specifications Fuel information You must only use unleaded gasoline in your vehicle. Select octane rating 87 (Research Octane Number 91) or higher. Use of unleaded gasoline with an octane rating lower than 87 may result in engine knocking. Persistent knocking can lead to engine damage. At minimum, the gasoline you use should meet the specifications of ASTM D4814 in the U.S.A. and CGSB3.5-M93 in Canada. n Fuel tank opening for unleaded gasoline To help prevent incorrect fueling, your vehicle has a fuel tank opening that only accommodates the special nozzle on unleaded fuel pumps. n Gasoline quality In very few cases, driveability problems may be caused by the brand of gasoline you are using. If driveability problems persist, try changing the brand of gasoline. If this does not correct the problem, consult your Lexus dealer. n Gasoline quality standards l Automotive manufacturers in the U.S.A., Europe and Japan have developed a specification for fuel quality called the World-Wide Fuel Charter (WWFC), which is expected to be applied worldwide. l The WWFC consists of four categories that are based on required emission levels. In the U.S., category 4 has been adopted. l The WWFC improves air quality by lowering emissions in vehicle fleets, and improves customer satisfaction through better performance. n Recommendation of the use of gasoline containing detergent additives l Lexus recommends the use of gasoline that contains detergent additives to 6 Vehicle specifications avoid the build-up of engine deposits. l All gasoline sold in the U.S.A. contains detergent additives to clean and/or keep clean intake systems. 565