2011 Chevrolet Silverado 1500 Regular Cab Owner's Manual - Page 363

Driving and Operating 9-79 Fuel For diesel engine vehicles, see "Fuel for Diesel Engines" in the Duramax Diesel Supplement. For Vehicles with gasoline engines, please read this. Gasoline Use of the recommended fuel is an important part of the proper maintenance of this vehicle. To help keep the engine clean and maintain optimum vehicle performance, we recommend the use of gasoline advertised as TOP TIER Detergent Gasoline. Look for the TOP TIER label on the fuel pump to ensure gasoline meets enhanced detergency standards developed by auto companies. A list of marketers providing TOP TIER Detergent Gasoline can be found at www.toptiergas.com. See Fuel E85 (85% Ethanol) on page 9‑81. For all other vehicles, use only the unleaded gasoline described under Recommended Fuel on page 9‑79. Recommended Fuel 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 eighth 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 12‑1. Vehicles that have a FlexFuel badge and a yellow fuel cap can use either unleaded gasoline or ethanol fuel containing up to 85% ethanol (E85).