Lexus GS300 1998 Owner's Manual page 378

Oil capacity
Drain and refill
with filter
without filter
Oil grade
Recommended oil viscosity (SAE):
– COOLING SYSTEM
Capacity
Coolant type
– FUEL
Fuel type
Octane rating
– IGNITION SYSTEM
5.4 L (5.7 qt., 4.8 lmp.qt.)
5.1 L (5.4 qt., 4.5 lmp.qt.)
API SH, "Energy–Conserving II" or SJ,
"Energy–Conserving" multigrade engine oil or ILSAC
multigrade engine oil
7.7 L (8.1 qt., 6.8 lmp.qt.)
Ethylene – glycol coolant (Do not use alcohol type.)
62L005–1
Only UNLEADED
91 (Research octane number 96) or higher
Temperature range anticipated before next oil change
ENGINE
365