unleaded...besides that don't waste your money on premium gas, the car's not worth it.
5 w30
R-134
A 1998 Oldsmobile 88 takes ATP automatic transmission fluid. This is sold in most places that carry transmission fluid, or you can buy it through a dealer.
The recommended oil for an Oldsmobile Alero is SAE 5W-30 oil. If you live in a state that does not get freezing temperatures, 10W-30 is acceptable.
DOT3 is recommended
For a 1998 Oldsmobile Aurora, it is recommended to use premium unleaded gasoline with an octane rating of 91 or higher. Using higher octane fuel helps optimize engine performance and efficiency. Regular unleaded gasoline may be used in a pinch, but it could lead to knocking and reduced performance. Always consult the owner's manual for specific fuel recommendations.
any dex-cool coolant but you must make sure it say's dex-cool on it.
The recommended fluid is dexron 3
in the far left hand side. right above where the belt is . it is kind of hidden just under the windsheild.
5W30 is appropriate and recommended for all but the most severe service in North American GM cars, 1999 model year.
for my 2000 Chevy Venture I use DexCool. It is the ONLY one recommended by GM.
2003 oldsmobile