Depends on how old and where you live. I live in Arizona and I use Quaker State Higher Mileage, cause it is and older car. I use a weight of 10W-30 due to the extreme heat conditions here. Get 5W-30 if heat is not and issue and you have cold winters.
The oil capacity on a 1996 Geo Prizm is approximately 5 quarts. The recommended oil type is 10 W 30.
where is located the oil pressure switch for 94 geo prizm
3.9 Quarts in a 1996 SD with a filter change. 3.7 if you don't change filter.
5W30
Every 5.000 miles
4 quarts
I would recommend 5w-30
May have to change oil.
http://www.ehow.com/video_11_change-motor-oil.html this helped me HUGE!!!
1.6 liter holds three quarts with a filter change.
75-90 weight gear oil
chances are you need a new head gasket, or some other seal