Buick 1993 Century Owner's Manual page 227

Filling Your Tank
1
A
CAUTION:
Gasoline vapor is highly flammable.
It
burns
violently, and that can cause very bad injuries.
Don't smoke
if
you're near gasoline or
refueling your vehicle. Keep sparks, flames,
and smoking materials away from gasoline.
The cap is behind a hinged door on the left side of your
vehicle.
To take off the cap, turn it slowly to the left
(counterclockwise).
If you get gasoline on you and then something
ignites it, you could be badly burned. Gasoline
can spray out on you if you open the fuel filler
cap too quickly. This spray can happen if your
tank is nearly full, and is more likely in hot
weather. Open the fuel filler cap slowly and
wait for any "hiss" noise to stop. Then
unscrew the cap all the way.
When you put the cap back on, turn it to the right until
you hear a clicking noise.
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