1999 Lexus GS300 maintenance

ENGINE
382± ELECTRICAL SYSTEM
Battery ± Maintenance type battery
Specific gravity reading at 20C (68F):
Charging rates Quick charge
Slow charge
± Non±maintenance battery
Open voltage at 20C (68F):
Charging rates
1.260 Fully charged
1.160 Half charged
1.060 Discharged
15A max.
5A max.
12.7V Fully charged
12.3V Half charged
11.9V Discharged
[Voltage that is checked 20 minutes after the key is
removed with all the lights turned off]
5A max.

ENGINE
386± ELECTRICAL SYSTEM
Battery ± Maintenance type battery
Specific gravity reading at 20C (68F):
Charging rates Quick charge
Slow charge
± Non±maintenance battery
Open voltage at 20C (68F):
Charging rates
1.260 Fully charged
1.160 Half charged
1.060 Discharged
15A max.
5A max.
12.7V Fully charged
12.3V Half charged
11.9V Discharged
[Voltage that is checked 20 minutes after the key is
removed with all the lights turned off]
5A max.

ENGINE
387
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.
NOTICE
Do not use leaded gasoline. Use of leaded
gasoline will cause the three±way catalytic
converter to lose its effectiveness and the
emission control system to function improperly.
Also, this can increase maintenance costs.
Octane rating
Select premium unleaded gasoline with an Octane
Rating of 91 (Research Octane Number 96) or higher
for optimum engine performance. However, if such
premium type cannot be obtained, you may
temporarily 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, 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.
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

ENGINE
390The amount of engine oil consumed depends on the
viscosity of the oil, the quality of the oil and the way
the vehicle is driven.
More oil is consumed under driving conditions such as
high speeds and frequent acceleration and
deceleration.
A new engine consumes more oil, since its pistons,
piston rings and cylinder walls have not become
conditioned.
When judging the amount of oil consumption, keep
in mind that the oil may have become diluted,
making it difficult to judge the true level accurately.
For example, if a vehicle is used for repeated short trips
and consumes a normal amount of oil, the dipstick may
not show any drop in the oil level at all, even after 1000
km (600 miles) or more. This is because the oil is
gradually becoming diluted with fuel or moisture, making
it appear that the oil level has not changed.
The diluting ingredients evaporate out when the vehicle
is then driven at high speeds, as on an expressway,
making it appear that oil is excessively consumed after
driving at high speeds.
Importance of engine oil level check
One of the most important points in proper vehicle
maintenance is to keep the engine oil at the optimum
level so that oil function will not be impaired. Therefore,
it is essential that the oil level be checked regularly.
Lexus recommends that the oil level be checked every
time you refuel the vehicle.
NOTICE
Failure to check the oil level regularly could lead
to serious engine trouble due to insufficient oil.
For detailed information on oil level check, see
ºChecking the engine oil levelº on page 392.