Tire Information

255 - Section width / 45 - Ratio / R - Radial / 20 - Rim Diameter / 105 - Loading Indexr / W - Speed Level

Section width (mm) :

The distance between both sides when inflated.

Ratio (%):

Also called aspect ratio, section height / section weight. The section weight is half as the difference between outside diameter and rim diameter.The lower the ratio is, the wider the section width will be, which means it will be safer to drive. The elasticity of sidewall will increase corresponding to the section width to make driving more stable. The high-speed cars using low ration tires is a trend nowadays.

Speed Rating

The speed level is marked on sidewall of every tire, which will indicate the maximum speed. For example: for the size 255/45R20 105W, the speed level is W, so that the max speed will be 270 Kilometer/hour by referring the speed comparison table. The speed level and specific info will be marked on all the stickers for every brand in Delinte.

The tire has bigger chance to get damage when driving at high speed, and the reaction time to avoid the accident will be reduced as well. For your own safety, you are suggested not to exceed the max speed according to the legislation at every driving condition.

Loading Index

The loading index is marked on sidewall of every tire, and the max loading capacity is marked as well. For example: for the size 255/45R20 105W, the loading index is 105, which corresponds the max loading capacity is 925 kilograms. Overloading will make tire over heated and break abruptly.

For radial tires, there are generally 3 methods to marking : ISO marking, P marking and EU marking.

• ISO Marking (International Standard)

EG: 195/60R14 86H The section width is 195, Ratio is 60. R is short for radial, the diameter of rim is 14 inch Loading Index is 86, speed level is H.

• P marking method (American Standard)

EG: P 195/60R14 86H P indicates passenger car, Section width is 195, ratio is 60. R means radial structure, rim diameter is 14, Loading Index is 86, speed level is H.

• EU mark (EU Standard)

EG: 185R14 90S Ratio is not marked out, which should be 80 in general. Others index is the same as ISO marking method.

DOT - Department of transportation

P2 - Factory code

AJ - Size code

CA - Pattern code

5C - Factory number

50 - Production week

14 - Production year

What is UTQG?

The UTQG on the sidewall is a general quality grading, which is the abbreviation for Uniform Tire Quality Grading System, classifying tires according to the wear ability, traction and febrile index. All the manufactures are in accordance with provisions of experimental steps. Authorized testing results should be classified and marked on the sidewall by the manufactures. According to US government regulation, all the tires imported to America must have UTQG data.

Treadwear

The testament of tread wear can only be done at government appointed place – locating near St. Angelo, Texas, where there is an express way of 400 miles. All the tested cars are supposed to run across this road to guarantee the same experimental conditions. The depth of pattern is measured in every 1288 miles, so are the compared tires. After 11592 miles, the tested and referential tires will be compared, through which the tires can be classified according to the wear ability. Abrasion index is indicated by numbers. For instance: if 100 is set as a cardinal number(standard). The abrasion of 100 can be used for 30000 miles, which means the abrasion of 400 can run 30000*4 = 120000 miles. This is just a reference data running on the appointed road. In fact the rate of wear ability is relating to the car's conditions and driving habits. According to legislation of American UTQG, the abrasion index of summer tire is between 160 - 300. The index that is between 160 - 200 is utility summer tire, between 300 - 540 is all season tire. The wear ability can only be applied under the same brand, not among different brands.

Traction

The traction demonstrates the parking performance on the wet straight road, which is represented by alphabets. For instance: the tire with AA can stop in the short time compared with the tire with C on straight wet ground. The traction demonstrates the parking performance on the wet straight road, which is represented by alphabets. For instance: the tire with AA can stop in the short time compared with the tire with C on straight wet ground.

Temperature

Temperature refers to the resistant ability of heat producing when tires are tested on the appointed wheels in lab. Continuous high temperature will cause tire aging, shorten service life. And overheat will lead to blowing up. Therefore, DOT prescribes that all the tires must meet the federal motor vehicles safety standard. The 109th of this legislation prescribes that tires must get the “C” grade, which lowest requirement under 136km/h. “B” and “A” grade means the tire is exceeding the DOT's basic demands.
Grade A over 6:31H / Grade B 5:01H-6:30H / Grade C 3:30H-5:00H

The original tire size can be found from owner's booklet, groove of left front door, storage box, and the lid of gas tank. Tire size can also be checked on the sidewall of current tire.