Gasoline Octane - Hummer 2003 H2 Owner's Manual

CAUTION:
You can be injured and your vehicle could be
damaged if you try to do service work on a
vehicle without knowing enough about it.
D
Be sure you have sufficient knowledge,
experience, the proper replacement parts
and tools before you attempt any vehicle
maintenance task.
D
Be sure to use the proper nuts, bolts and
other fasteners. "English" and "metric"
fasteners can be easily confused. If you use
the wrong fasteners, parts can later break
or fall off. You could be hurt.
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"
in the Index.

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
If you are using 87 octane or higher
you hear heavy knocking, your engine needs service.
-
octane fuel is necessary.
-
octane fuel and
6-3