Tire size
245/45 R 18 96 Y
245: nominal width in mm
45: aspect ratio in %
R: radial tire code
18: rim diameter in inches
96: load rating, not for ZR tires
Y: speed rating, before the R on ZR tires
Maximum tire load
Maximum tire load is the maximum permissible weight for which the tire is approved.
Locate the maximum tire load on the tire sidewall and the Gross Axle Weight Rating - GAWR - on the certification label on the driver door B-pillar.
Divide the tire load by 1.1. It must be greater than one-half of the vehicle's Gross Axle Weight Rating - GAWR. Note, front vs. rear GAWR and tire loads, respectively.
Speed letter
Tire Identification Number
DOT-Code: DOT xxxx xxx 0120
xxxx: manufacturer code for the tire brand
xxx: tire size and tire design
0120: tire age
Tires with DOT codes meet the guidelines of the
U.S. Department of Transportation.
Tire age
Recommendation
Regardless of the tire tread, replace tires at least every 6 years.
Manufacture date
You can find the manufacture date of the tire on the tire's sidewall.
Uniform Tire Quality Grading
Quality grades can be found where applicable on the tire sidewall between tread shoulder and maximum section width.
E.g.: Treadwear 200; Traction AA; Temperature A
DOT Quality Grades
Treadwear
Traction AA A B C
Temperature A B C
All passenger vehicle tires must conform to Federal Safety Requirements in addition to these grades.
Treadwear
The treadwear grade is a comparative rating based on the wear rate of the tire when tested under controlled conditions on a specified government test course. E.g., a tire graded 150 would wear one and one-half, 1 g, times as well on the government course as a tire graded 100.
The relative performance of tires depends upon the actual conditions of their use, however, and may depart significantly from the norm due to variations in driving habits, service practices and differences in road characteristics and climate.
Traction
The traction grades, from highest to lowest, are AA, A, B, and C.
Those grades represent the tire's ability to stop on wet pavement as measured under controlled conditions on specified government test surfaces of asphalt and concrete. A tire marked C may have poor traction performance.
The traction grade assigned to this tire is based on straight-ahead braking traction tests, and does not include acceleration, cornering, hydroplaning, or peak traction characteristics.
Temperature
The temperature grades are A, the highest, B, and C, representing the tire's resistance to the generation of heat and its ability to dissipate heat when tested under controlled conditions on a specified indoor laboratory test wheel. Sustained high temperature can cause the material of the tire to degenerate and reduce tire life, and excessive temperature can lead to sudden tire failure.
The grade C corresponds to a level of performance which all passenger car tires must meet under the Federal Motor Vehicle Safety Standard No. 109. Grades Band A represent higher levels of performance on the laboratory test wheel than the minimum required by law.
Warning
The temperature grade for this tire is established for a tire that is properly inflated and not overloaded. Excessive speed, underinflation, or excessive loading, either separately or in combination, can cause heat buildup and possible tire failure.
RSC - Run-flat tires
Run-flat tires, refer to page 341, are labeled with a circular symbol containing the letters RSC marked on the sidewall.
M+S
Winter and all-season tires with better cold weather performance than summer tires.