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

Gasoline Octane

For all vehicles, except those with the 6.0L V8
engine (VIN Code N), use regular unleaded
gasoline with a posted octane rating of 87 or
higher. If the octane rating is less than 87,
you may 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, your engine needs service.
If your vehicle has the 6.0L V8 engine
(VIN Code N), use premium unleaded gasoline
with a posted octane rating of 91 or higher.
You may also use regular unleaded gasoline rated
at 87 octane or higher, but your vehicle's
acceleration may be slightly reduced, and you
may notice a slight audible knocking noise,
commonly referred to as spark knock. If the octane
is less than 87, you may notice 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. If you are using gasoline rated at
87 octane or higher and you hear heavy knocking,
your 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 472 for additional information.

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 258. 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.
471