525
6-1. Specifications
6
Vehicle specifications
IS350/250_U
Fuel information
■Fuel tank opening for unleaded gasoline
To help prevent incorrect fueling, your Lexus has a fuel tank opening that only
accommodates the special nozzle on unleaded fuel pumps.
■If your engine knocks
●Consult your Lexus dealer.
●You may occasionally notice light knocking for a short time while accelerating
or driving uphill. This is normal and there is no need for concern.
Your vehicle must use only unleaded gasoline.
IS250
Premium unleaded gasoline with an octane rating of 91 (Research Octane
Number 96) or higher required for optimum engine performance. If 91
octane cannot be obtained, you may use unleaded gasoline with an octane
rating as low as 87 (Research Octane Number 91). Use of unleaded gaso-
line with an octane rating lower than 91 may result in engine knocking. Per-
sistent knocking can lead to engine damage and should be corrected by
refueling with higher octane unleaded gasoline.
IS350
Premium unleaded gasoline with an oc tane rating of 91 (Research Octane
Number 96) or higher required for optimum engine performance. If 91
octane cannot be obtained, you may use unleaded gasoline with an octane
rating as low as 87 (Research Octane Number 91). Use of unleaded gaso-
line with an octane rating lower than 91 may result in engine knocking and
significantly reduced performance. Persistent knocking can lead to engine
damage and should be corrected by refueling with higher octane unleaded
gasoline.
At minimum, the gasoline you use should meet the specifications of
ASTM D4814 in the U.S.A. and CGSB3.5-M93 in Canada.
