Chevrolet Impala Owner's Manual page 324

Tires need the correct amount of
air pressure to operate
effectively.
Neither tire underinflation nor
overinflation is good.
Underinflated tires, or tires
that do not have enough air,
can result in:
Tire overloading and
overheating which could
lead to a blowout.
Premature or
irregular wear.
Poor handling.
Reduced fuel economy.
Overinflated tires, or tires that
have too much air, can
result in:
Unusual wear.
Poor handling.
Rough ride.
Needless damage from
road hazards.
The Tire and Loading
Information label on the vehicle
indicates the original equipment
tires and the correct cold tire
inflation pressures. The
recommended pressure is the
minimum air pressure needed to
support the vehicle's maximum
(Continued)
load carrying capacity. See
.
How the vehicle is loaded
affects vehicle handling and ride
comfort. Never load the vehicle
with more weight than it was
designed to carry.
Check the tires once a month or
more. Do not forget the compact
spare, if the vehicle has one.
The cold compact spare tire
pressure should be at 420 kPa
(60 psi). See
.
Use a good quality pocket-type
gauge to check tire pressure.
Proper tire inflation cannot be
determined by looking at the tire.
Check the tire inflation pressure
when the tires are cold, meaning
the vehicle has not been driven
for at least three hours or no
more than 1.6 km (1 mi).