GMC 2012 Sierra Series Owner's Manual page 529

Application
Engine Oil with Filter
4.3L V6
4.8L V8; 5.3L V8; 6.0L V8; 6.2L V8
Fuel Tank
1500 Series Standard and Short Box
1500 Series Long Box
2500 Series and 3500 Series Standard Box
2500 Series and 3500 Series Long Box
3500 Series Chassis Cab
3500 Chassis Cab Front Tank
3500 Chassis Cab Rear Tank (if equipped)
Transfer Case Fluid
Metric
4.3 L
5.7 L
98.4 L
128.7 L
136.3 L
136.3 L
240.4 L
89.0 L
151.4 L
1.5 L
I n f o r ma t i o n P r o v i d e d b y :
Technical Data
Capacities
English
4.5 qt
6.0 qt
26.0 gal
34.0 gal
36.0 gal
36.0 gal
63.5 gal
23.5 gal
40.0 gal
1.6 qt
12-3