1993 GMC SIERRA octane

Service & Appearance Care
1 If you try to do your own service work without knowing enough ab\
out it, I
1 your vehicle could be damaged.
Maintenance Schedule
Section 7 of this manual, “Scheduled Maintenance Services”, explains the \
maintenance your new vehicle needs, and when
it -should be done. It also,
has a form that you can use to record the maintenance work done \
on your
vehicle. Be sure to read this ,information.
-I .. >. ’ , .
Fuel (Gasoline Engines)
If your vehicle has a diesel engine, see “Diesel Fuel Requi\
rements and Fuel
System’’ in this Section: For vehicles with gasoline engines, please read this.
Use regular unleaded gasoline rated at 87 octane or’higher.
It should meet
specifications ASTM D4814 in the
U.S. and CGSB 3.592 in Canada. These
fuels should have the proper additives,
so you should not have to add
anything to the fuel.
In the
U.S. and Canada, it’s easy to be sure you get the right kind of
gasoline (unleaded). You’ll see
UNLEADED right on the pump. And only
unleaded nozzles
will fit into your vehicle’s filler neck.
Be sure the posted octane is at least 87. If the octane
is less than 87, you
may get a heavy knocking noise when you drive.
If it’s bad enough, it can
damage your engine.
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If you’re using fuel rated at 87 octane or higher and you still hear heavy
knocking, your engine needs service. But don’t worry
if you hear a little
pinging noise when you’re accelerating or driving up a hill. That’s normal and
you don’t have
to buy a higher octane fuel to get rid of pinging. It’s the
heavy, constant knock that means you have a problem.
What about gasoline with blending materials that contain oxygen,\
such as MTBE or alcohol?
MTBE is “methyl tertiary-butyl ether.” Fuel that is no more than 15% MTBE is
fine for your vehicle.
Ethanol is ethyl or grain alcohol. Properly-blended fuel that is no more than
10% ethanol is fine for your vehicle.
Methanol is methyl or wood alcohol.
le1 that is more than
5% methanol is bad for your vehicle. Don’t use it.
can corrode metal parts in your fuel system and also damage plastic
and rubber parts. That damage wouldn’t be covered under your warranty
And even at
5% or less, there must be “cosolvents” and corrosion
- ~wenters in this fuel to help avoid these problems.
Gasolines for CIeaner Air
Your use of gasoline with detergent additives will help prevent depo\
sits from
forming in your engine and fuel system. That helps keep your engine in tune
and your emission control system working properly. It’s good \
for your vehicle,
and you’ll be doing your part for cleaner air.
Many gasolines are now blended with materials that called
oxygenates.General Motors recommends that you use gasolines with \
these
blending materials, such as MTBE and ethanol. By doing
so, you can help
clean the air, especially in those parts
of the country that have higher carbon
monoxide levels.
In addition, some gasoline suppliers are now producing reformulated \
gasolines. These gasolines are specially designed to reduce vehicle
emissions. General Motors recommends that you use reformulated g\
asoline.
By doing
so, you can help clean the air, especially in those parts of the
country that have high ozone levels.
You should ask your service station operators
if their gasolines contain
detergents and oxygenates, and
if they have been reformulated to reduce
vehicle emissions.
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