Adding Equipment To The Outside Of Your Vehicle; Fuel; Gasoline Octane - Chevrolet 2004 Impala Owner's Manual

CAUTION: (Continued)
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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

Use of the recommended fuel is an important part of the
proper maintenance of your vehicle.
5-4

Gasoline Octane

If your vehicle has the 3400 V6 engine (VIN Code E) or
the 3800 V6 engine (VIN Code K), 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
you hear heavy knocking, your engine needs service.
If your vehicle has the 3800 Supercharged V6
engine (VIN Code 1), use only premium unleaded
gasoline with a posted octane of 91 or higher. In
an emergency, you may be able to use a lower
octane — as low as 87 — if heavy knocking does not
occur. Refill your tank with premium fuel as soon
as possible. Otherwise, you might damage your engine.
If you are using 91 octane or higher-octane fuel and
you hear heavy knocking, your engine needs service.