Look in your owners manual. It should be listed under capacities. On a 2000 1.8 turbo it is approximately 4.5 qts.
6 qts. according to the owners manual
V6 4.5 qts. with new filter V8 6 qts. with new filter.
6 Qts. with new filter.
engine oil is 6 qts trans is 5 qts with deep pan
6 QTS. with new filter.
4.5 qts
6 qts with filter.
I say 5 qts of motor oil. i would put 4 qts in and add as needed.
If the Sierra is a duramax Deisel the it holds 12 qts. If it's a gasoline engine then it holds 5 qts
10 quarts.
6 qts for the 3.5
6 qts