fuel additives Lexus GX470 2006 Gauges, Meters and Service Reminder Indicators / LEXUS 2006 GX470 OWNER'S MANUAL (OM60B99U)

ENGINE
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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 standard 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.
NOTICE
Do not use leaded gasoline. Use of leaded gasoline will
cause the threeway catalytic converter to lose its
effectiveness and the emission control system to
function improperly. Also, this can increase
maintenance costs.
Octane rating
Premium unleaded gasoline with an Octane Rating of 91
(Research Octane Number 96) or higher required for
optimum engine performance. However, if such premium
type cannot be obtained, you may use unleaded gasoline
with an Octane Rating as low as 87 (Research Octane
Number 91).
Use of unleaded fuel with an octane number or rating lower
than stated above will cause persistent heavy knocking. If
severe, this will lead to engine damage.
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, occasionally, you may notice light knocking for a
short time while accelerating or driving up hills. This is normal
and there is no need for concern.
Gasoline containing detergent additives
Lexus recommends the use of gasoline that contains
detergent additives to avoid buildup of engine deposits.
However, all gasoline sold in the U.S. contains detergent
additives to keep clean and/or clean intake systems.