fuel consumption PONTIAC FIERO 1988 Service Repair Manual

TIRES AND WHEELS 3E-3
METRIC WHEEL NUTS AND STUDS
Some models use metric wheel nuts and wheel
studs. The nut will have the word "metric" stamped on
its face and the stud will have the letter
"M" stamped
into the threaded end. The word "metric" is stamped
on its head.
The thread size of the metric wheel nuts and
wheel studs are
"MI2 x 1.5". These stand for:
M = Metric
12
= Diameter in millimeters
1.5
= Millimeters per thread
If a broken stud is found, see Section 3C (Front
Suspension) or Section 3D (Rear Suspension) for
replacement procedure.
INFLATION OF TIRES
The pressure recommended for any model is
carefully calculated to give a satisfactory ride,
handling, tread life and load carrying capacity.
Tire pressure, with tires cold, (after car has set for
three hours or more, or driven less than one mile)
should be checked monthly or before any extended trip
and set to the specifications on the tire placard located
on rear face of driver's door. Tire inflation pressure is
also given in Section OB.
Valve caps or extensions should be on the valves
to keep dust and water out.
1. For sustained driving at speeds up to 85
mph (140 km/h), in countries where such
speeds are allowed by law, your tires should be set
at the pressures recommended on your tire
placard.
Sustained driving at speeds
faster than
85 mph (140 km/h), where
permitted
by law, is not advised unless
your car has special high speed tires available
from many tire dealers.
2. Tire pressures may increase as much as 6 psi
when hot.
3. Higher
than recommended pressure can cause:
o Hard ride
o Tire bruising or carcass damage
Rapid tread wear at center of tire
4. Lower
than
recommended pressure can cause:
@ Tire squeal on turns
@ Hard steering
o Rapid and uneven wear on the edges of the
tread
Tire rim bruises and rupture
e Tire cord breakage
o High tire temperatures
o Reduced handling
High fuel consumption
5. Unequal pressure on same axle can cause:
Uneven braking
o Steering lead
o Reduced handling
e Swerve on acceleration
TlRE ROTATION
Fig. 5
To equalize wear, rotate tire and wheel assemblies
at intervals specified in Section OB. In addition to
scheduled rotation, the tire and wheel assemblies
should also be rotated whenever uneven tire wear is
noticed.
Due to their design, radial tires tend to wear
faster in the shoulder area particularly in front
positions. Radial
tires in non-drive
iocations may
develop an irregular wear pattern that can increase tire
noise if not rotated. This makes regular rotation
especially necessary.
After rotation, be sure to check wheel nuts for
specified torque.
On
F Carline with P245/50VR16 tires and 16"
wheels, special rotation provisions must be followed.
Since the tires are directional, and the front and rear
wheels have different offsets, the tires must be
dismounted from the wheels for rotation. Remove the
tires from the wheels, and mount on the appropriate
wheel, as shown in the rotation diagram. Be sure the
arrows on the tires point in the direction the tire turns.
Rebalance the
tire/wheel assemblies using
nylon-coated weights. Adjust
F/R tire pressures, and
torque wheel nuts to specifications.
ACCEPTABLE ROTATION PATTERN
FOR REAR WHEEL
DRIVE GARS
DO NOT INCLUDE "TEMPORARY USE ONLY" SPARE TlRE IN ROTATION
Fig. 5 Tire Rotation - Rear-Wheel Drive