Chevrolet 1995 Lumina Owner's Manual page 74

OVERDRIVE
( a ) :
This position is for normal driving.
If you need more power for passing, and you're:
0
Going less than 35 mph (55
km/h),
push your
accelerator pedal about halfway down.
0
Going about 35 mph (55
km/h)
or more, push the
accelerator all the way down.
You'll shift down to the next gear and have more
power.
I
NOTICE:
If
your vehicle seems to start up rather slowly, or
if it seems not to shift gears as you go faster,
something may be wrong with a transaxle system
sensor. If you drive very far that way, your
vehicle can be damaged. So, if this happens, have
your vehicle serviced right away. Until then, you
can use SECOND (2) when you are driving less
than 35 mph
(55 km/h)
and OVERDRIVE (0)
for higher speeds.
DRIVE (D): DRIVE (D) is like OVERDRIVE
( a ) ,
but
you never go into overdrive. Here are some times you
might choose DRIVE (D) instead of
OVERDRIVE (@):
0
When driving on hilly, winding roads.
0
When towing a trailer, so there is less shifting
between gears.
0
When going down a steep hill.