3896-1. Specifications6Vehicle specificationsFuel informationnFuel tank opening for unleaded gasolineTo help prevent incorrect fueling, your Lexus has a fuel tank opening that onlyaccommodates the special nozzle on unleaded fuel pumps.nIf premium gasoline is not availableIf this premium fuel is not available, you may use unleaded gasoline with an OctaneRating of 87 or so (Research Octane Number 91). IS250: The use of such gasoline will cause persistent heavy knocking. If severe, thiswill lead to engine damage.IS350: The use of such gasoline may cause the engine to knock or drasticallyreduce output to protect itself while driving with a heavy load. To avoid this, refill thetank with premium unleaded gasoline as soon as possible.nIf your engine knockslConsult your Lexus dealer.lYou may occasionally notice light knocking for a short time while acceleratingor driving uphill. This is normal and there is no need for concern.nGasoline qualityIn very few cases, driveability problems may be caused by the brand of gasoline youare using. If driveability problems persist, try changing the brand of gasoline. If thisdoes not correct the problem, consult your Lexus dealer.Your vehicle must use only unleaded gasoline.Premium unleaded gasoline with an Octane Rating of 91 (ResearchOctane Number 96) or higher required for optimum engine performance.At minimum, the gasoline you us e should meet the specifications ofASTM D4814 in the U.S.A. and CGSB3.5-M93 in Canada.
