Fuel; Gasoline Octane; Gasoline Specifications; California Fuel - Chevrolet 2007 Colorado Owner's Manual

Fuel

Use of the recommended fuel is an important
part of the proper maintenance of your vehicle.
To help keep the engine clean and maintain
optimum vehicle performance, GM recommends
the use of gasoline advertised as TOP TIER
Detergent Gasoline.

Gasoline Octane

Use regular unleaded gasoline with a posted
octane rating of 87 or higher. If the octane rating is
less than 87, you might notice an audible knocking
noise when you drive, commonly referred to as
spark knock. If this occurs, use a gasoline rated at
87 octane or higher as soon as possible. If you are
using gasoline rated at 87 octane or higher and you
hear heavy knocking, the engine needs service.
Gasoline Specifications
At a minimum, gasoline should meet ASTM
specification D 4814 in the United States or
CAN/CGSB-3.5 in Canada. Some gasolines
may contain an octane-enhancing additive
called methylcyclopentadienyl manganese
tricarbonyl (MMT). General Motors recommends
against the use of gasolines containing MMT. See
Additives on page 326 for additional information.
326

California Fuel

If your vehicle is certified to meet California
Emissions Standards, it is designed to operate
on fuels that meet California specifications.
See the underhood emission control label.
If this fuel is not available in states adopting
California emissions standards, your vehicle will
operate satisfactorily on fuels meeting federal
specifications, but emission control system
performance may be affected. The malfunction
indicator lamp may turn on and your vehicle may
fail a smog-check test. See Malfunction Indicator
Lamp on page 192. If this occurs, return to
your authorized GM dealer for diagnosis. If it is
determined that the condition is caused by the
type of fuel used, repairs may not be covered
by your warranty.

Additives

To provide cleaner air, all gasolines in the
United States are now required to contain additives
that will help prevent engine and fuel system
deposits from forming, allowing your emission
control system to work properly.