It depends on the climate you live in but in most cases a 5W-30 is fine.
On the oil cap it says "5 W 30".
5W30 weight
5W30 weight ONLY. Gastrol and kendell brands are a real good oil to use.
Yes, there is no reason you should not be able to change the oil by yourself in a 1996 Chevrolet S10.
It is in the oil pan.
Kind does not matter but the weight does. It requires 5 quarts of 5W-30 with the filter change.
According to the 1996 Mercury Grand Marquis owners manual ( 5W-30 engine oil ) is the PREFERRED oil weight
Rotella
According to the 1996 Mercury Grand Marquis Owner Guide ( 5W-30 is the PREFERRED engine oil )
4 quarts with oil filter
The oil pressure switch on a 1996 Chevrolet Cavalier is on the rear of the engine block. It will be directly above the oil pan.
5 qts. with a new filter.