Pontiac 1993 Grand Am Owner's Manual page 200

Fuel
2.3L Quad OHC and Quad 4 Engines
(Codes 3 and D) and 3300 V6 Engine
(Code N ) :
The 8th digit of your Vehicle
Identification Number (VIN) shows the
code letter for your engine. You will
find the VIN at the top left of your
instrument panel. (See the I d e x under
&hicle Identijkation Number.)
Use regular unleaded gasoline rated at
87 octane or higher. It should meet
specifications ASTM D4814 i n the U.S.
and CGSB 3.5-92 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.
1 9 s