MAINTENANCE
LOAD AND INFLATION CHART
WIDE BASE TIRES FOR TRUCKS, BUSSES, TRAILERS AND
MULTIPURPOSE PASSENGER VEHICLES USED IN HIGHWAY SERVICE
(Bias and Radial Ply Tubeless)
TIRE AND RIM ASSOCIATION STANDARD
TIRES USED AS SINGLES
Tire Identification
Tire Load Limits at Various Inflation Pressures
Size
Load Range
45
50
55
60
65
70
75
80
16.5 x 22.5
H
6590
7010
7410
7790
8170
8540
8890
9230
TIRES USED AS DUALS
Tire Identification
Tire Load Limits at Various Inflation Pressures
Size
Load Range
55
60
65
70
75
80
12.00 x 20
G
4930
5190
5440
5680
5910
6140
NOTE:
For sustained high speed driving over 6 mph, cold inflation pressures must be increased 10 psi
0
above those specified by the table for the load being carried (but not to exceed 100 psi). Where the 10
psi pressure adjustment for sustained high speed is limited by the maximum of 100 psi, speed must
be limited to 60 mph. (COLD INFLATION PRESSURES MUST NEVER EXCEED 100 PSI.)
TIRE MATCHING (DUAL TIRES)
CONVERSION OF PLY RATING TO
LOAD RANGE DESIGNATION
Use care in matching dual tires. Tires which differ
more than 1/4 inch in diameter of 3/4 inch in
circumference should not be mounted on the same dual
Load Range
Replaces Ply Rating
wheel. Should it become necessary to mount two tires
of unequal size on the same dual wheel, place the larger
A
2
or less worn tire on the outside.
B
4
TIRE MATCHING (TANDEM DRIVE AXLES)
C
6
When mounting tires on tandem drive axles, follow
D
8
the same instructions as specified for dual tires.
However, never install the four largest tires on one
E
10
driving axle and the four smallest tires on the other. This
method of tire mounting will cause high axle lubricant
F
12
temperatures which may lead to premature axle failure.
G
14
TIRE SWITCHING SEQUENCE
H
16
Tires should be cross switched at regular intervals to
J
18
attain maximum tire life.
L
20
FRONT WHEEL ALIGNMENT
M
22
To guard against excessive tire wear, have the front
wheel alignment inspected occasionally by your IH
N
24
Branch or Dealer for toe-in.
24
