Hummer 2010 H3 - Manual (Page 248)

9-64 Driving and Operating
Fuel
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 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 12‑1.
If the vehicle has the 5.3L V8 engine
(VIN Code P), you can use either
unleaded gasoline or ethanol fuel
containing up to 85% ethanol (E85).
See Fuel E85 (85% Ethanol) on
page 9‑66. In all other engines, use
only regular unleaded gasoline.
Recommended Fuel
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.