GMC C-Series 2001, Owner'S Manual, Page: 206 / 324

6-4
Fuel (Gasoline Engine)
If your vehicle has a diesel engine, see “Diesel Engine
Fuel” in this section. For vehicles with gasoline engines,
please read this.
Use regular unleaded gasoline rated at 87 octane or
higher. It is recommended that the gasoline meet
specifications which were developed by the American
Automobile Manufacturers Association (AAMA) and
endorsed by the Canadian Motor Vehicle Manufacturers
Association for better vehicle performance and
engine protection. Gasolines meeting the AAMA
specification could provide improved driveability and
emission control system performance compared to
other gasolines.
In Canada, look for the
“Auto Makers’ Choice”
label on the fuel pump.
Canada Only
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.
If you’re using fuel rated at 87 octane or higher and you
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.