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Tire
matching on dual wheel positions is absolutely critical
in obtaining the best performance of any tire, whether
it be new or a retread. Mismatched duals have the same
effect on tires as running them low on air pressure.
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A
difference of only 15 PSI between a set of duals can
increase the load on the tire w/higher PSI by 500lbs
for a total of 1000lbs load carrying differential
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A
difference on 1/4" diameter between duals can
increase the load on the larger tire by 600lbs for a
total 1200lbs load carrying differential
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As
these differences increase, the inequalities in load
increase and so does the chance of damage to the
tires
In
addition to matching tire diameter, load carrying, and
inflation pressures, it is very important to NEVER mix
radials and bias ply tires on the same axle. Radial
tires are designed to flex more under a given load. This
will place a much greater burden on a bias tire placed
next to it and greatly increases the chance of a tire
failure due to an overloaded condition.
General
rules for tire diameter matching tolerances on duals are
listed below. It is important to note that on twin
screw, tandem drive rear axle vehicles, all 8 tires are
required to be within 1/4" diameter of one another. It
is necessary to closely match revolutions per mile on
all 8 tires. Ignoring this fact will result in uneven
tire wear, loss of traction, and can result in possible
mechanical damage to the vehicle. |
