Page 326 of 496

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 Speci cations
At a minimum, gasoline should meet ASTM
speci cation 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 326for additional information.
California Fuel
If your vehicle is certi ed to meet California
Emissions Standards, it is designed to operate
on fuels that meet California speci cations.
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
speci cations, but emission control system
performance may be affected. The malfunction
indicator lamp may turn on and your vehicle may
fail a smog-check test. SeeMalfunction 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.
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Page 329 of 496

{CAUTION:
Fuel can spray out on you if you open the
fuel cap too quickly. If you spill fuel and
then something ignites it, you could be
badly burned. This spray can happen if
your tank is nearly full, and is more likely
in hot weather. Open the fuel cap slowly
and wait for any hiss noise to stop. Then
unscrew the cap all the way.
Be careful not to spill fuel. Do not top off or over ll
the tank and wait a few seconds after you have
nished pumping before removing the nozzle.
Clean fuel from painted surfaces as soon as
possible. SeeWashing Your Vehicle on page 426.
When replacing the fuel cap, turn it clockwise
until it clicks. Make sure the cap is fully installed.
The diagnostic system can determine if the
fuel cap has been left off or improperly installed.
This would allow fuel to evaporate into the
atmosphere. If the fuel cap is not properly installed,the FUEL CAP message will appear on the Driver
Information Center (DIC) and the check engine
light will be lit on the instrument panel cluster.
SeeDIC Warnings and Messages on page 202
andMalfunction Indicator Lamp on page 192
for more information.
{CAUTION:
If a re starts while you are refueling,
do not remove the nozzle. Shut off the
ow of fuel by shutting off the pump
or by notifying the station attendant.
Leave the area immediately.
Notice:If you need a new fuel cap, be sure
to get the right type. Your dealer/retailer
can get one for you. If you get the wrong type,
it may not t properly. This may cause your
malfunction indicator lamp to light and
may damage your fuel tank and emissions
system. SeeMalfunction Indicator Lamp
on page 192.
329
Page 381 of 496

(D) Construction Code:A letter code is used
to indicate the type of ply construction in the tire.
The letter R means radial ply construction; the
letter D means diagonal or bias ply construction;
and the letter B means belted-bias ply
construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:These characters
represent the load range and speed rating of the
tire. The load index represents the load carry
capacity a tire is certi ed to carry. The load index
can range from 1 to 279. The speed rating is the
maximum speed a tire is certi ed to carry a load.
Speed ratings range from A to Z.
Tire Terminology and De nitions
Air Pressure:The amount of air inside the tire
pressing outward on each square inch of the tire.
Air pressure is expressed in pounds per square
inch (psi) or kilopascal (kPa).
Accessory Weight:This means the combined
weight of optional accessories. Some examples of
optional accessories are, automatic transmission,
power steering, power brakes, power windows,
power seats, and air conditioning.Aspect Ratio:The relationship of a tire’s height
to its width.
Belt:A rubber coated layer of cords that is located
between the plies and the tread. Cords may be
made from steel or other reinforcing materials.
Bead:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.
Bias Ply Tire:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread.
Cold Tire Pressure:The amount of air pressure
in a tire, measured in pounds per square inch (psi)
or kilopascals (kPa) before a tire has built up heat
from driving. SeeIn ation - Tire Pressure on
page 384.
Curb Weight:This means the weight of a motor
vehicle with standard and optional equipment
including the maximum capacity of fuel, oil, and
coolant, but without passengers and cargo.
381