Depends on what part of the country you live in. If its mostly cold weather you need a lower viscosity like 10W30. If you live where its hot try 5W30. If its a neutral climate try 15W40.
It is in the oil pan.
While owning a vehicle is important to know the engine oil capacity. In a 1991 Chevrolet Silverado truck the oil capacity is five quarts of oil with the filter change.
Maybe one of these videos can help you: http://www.sutree.com/Learn.aspx?q=change+oil+in+chevrolet
7 quarts is the recommended amount of oil in a 1999 Chevrolet Silverado 3500. You should change your oil every 3 months or every 5,000 miles in this truck.
motor oil
Kind does not matter but the weight does. It requires 5 quarts of 5W-30 with the filter change.
Use the exact weight as listed on the oil fill cap or in your owners manual. Any major brand is good.
5w30
well what kind of truck and what engine?
You need to change your oil then turn the key so your electrical will come on but do not start the truck. Once you have done this pump the gas petal 3 times kind of quick(if you do it too quick or too slow it will not reset). Once you do this you should hear a series of chimes or dings, once this stops you change oil message should go away.
American Motors, Chevrolet, Dodge, Dodge truck, Jeep truck, Mitsubishi truck, Peugeot, Renault, Winnebago,
You should change your oil in your new truck every three thousand miles at least. You should check your oil once in a while. If its a new truck check oil every month.