Hummer 2004 H2 - Manual (Page 319)

Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle can
affect the airflow around it. This may cause wind
noise and affect windshield washer performance. Check
with your dealer before adding equipment to the
outside of your vehicle.
Fuel
The 8th digit of your vehicle identification number (VIN)
shows the code letter or number that identifies your
engine. You will find the VIN at the top left of the
instrument panel. See Vehicle Identification Number
(VIN) on page 5-101.
Gasoline Octane
Use regular unleaded gasoline with a posted octane of 87
or higher. If the octane is less than 87, you may get a
heavy knocking noise when you drive. If this occurs, use
a gasoline rated at 87 octane or higher as soon as
possible. Otherwise, you might damage your engine. A
little pinging noise when you accelerate or drive uphill is
considered normal. This does not indicate a problem
exists or that a higher-octane fuel is necessary. If you are
using 87 octane or higher-octane fuel and hear heavy
knocking, your engine needs service.
Gasoline Specifications
It is recommended that gasoline meet specifications
which were developed by automobile manufacturers
around the world and contained in the World-Wide Fuel
Charter which is available from the Alliance of
Automobile Manufacturers at www.autoalliance.org.
Gasoline meeting these specifications could provide
improved driveability and emission control system
performance compared to other gasoline.
In Canada, look for the
“Auto Makers’ Choice”
label on the pump.
Canada Only
5-5