2010 GMC Sierra 1500 Crew Cab Owner's Manual - Page 467

If the vehicle has the 5.3L V8 engine (VIN Code 0), the 5.3L V8 engine (VIN Code 3), the 6.0L V8 engine (VIN Code J), or the 6.2L V8 engine (VIN Code 2), you can use either unleaded gasoline or ethanol fuel containing up to 85% ethanol (E85). See Fuel E85 (85% Ethanol) on page 6‑10. In all other gasoline engines, use only unleaded gasoline. See Gasoline Octane on page 6‑7. Gasoline Octane For all vehicles except those with the 6.2L V8 engine (VIN Code 2), use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, an audible knocking noise, commonly referred to as spark knock, might be heard when driving. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If heavy knocking is heard when using gasoline rated at 87 octane or higher, the engine needs service. The 8th digit of the Vehicle Identification Number (VIN) shows the code letter or number that identifies the vehicle's engine. The VIN is at the top left of the instrument panel. See Vehicle Identification Number (VIN) on page 6‑128. 6-7