7
Speed rating. When stated, indicates the maximum speed (in mph) at which the tire can
be used for extended periods. Q=99 mph (160 km/h), R=106 mph (170 km/h), S=112 mph
(180 km/h), T=118 mph (190 km/h), U=124 mph (200 km/h), H=130 mph (210 km/h),
V=149 mph (240 km/h), W=168 mph (270 km/h), Y=186 mph (300 km/h).
8
Tire composition and materials. The number of plies in both the tread area and the
sidewall area indicates how many layers of rubber coated material make up the structure
of the tire. Information is also provided on the type of materials used.
9
Maximum tire load. The maximum load which can be carried by the tire.
10 Maximum permissible inflation pressure. This pressure should not be used for normal
driving.
11 U.S. DOT Tire Identification Number (TIN). Begins with the letters DOT and indicates that
the tire meets all federal standards. The next 2 digits/letters represent the plant code
where it was manufactured, and the last 4 digits represent the week and year of
manufacture. For example, the number 1712 is used to represent the 17th week of 2012.
The other numbers are marketing codes used at the manufacturer’s discretion. This
information can be used to contact consumers if a tire defect requires a recall.
12 Treadwear grade. This number indicates the tire’s wear rate. The higher the treadwear
number is, the longer it should take for the tread to wear down. A tire rated at 400, for
example, lasts twice as long as a tire rated at 200.
13 Traction grade. Indicates a tire’s ability to stop on wet roads. A higher graded tire should
allow you to stop your vehicle in a shorter distance than a tire with a lower grade. Traction
is graded from highest to lowest as AA, A, B, and C.
14 Temperature grade. The tire’s resistance to heat is grade A, B, or C, with A indicating the
greatest resistance. This grading is provided for a correctly inflated tire, which is being
used within its speed and loading limits.
Wheels and Tires
209
Specifications