GMC 2012 Sierra Denali Owner's Manual page 300

For diesel engine vehicles, see
Fuel for Diesel Engines in the
Duramax Diesel Supplement.
For Vehicles with gasoline engines,
please read this.
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.
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
.
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).
See
. For all other vehicles,
use only the unleaded gasoline
described under
.