Well I done some investagation and came up with this. They are a Korean tire Co.That have a joint venture with Michelin Korea Tire Co., LTD . and are just now starting to show up here in the states. and there web site is
http://www.nexentire.co.kr/english/main/index.asp and also found some helpful info sorry if it's a repost.
All passenger tires must conform to federal safety requirements in addition to these grades.
TREADWEAR
The tread wear grade is a comparative rating based on the wear rate of the tire when tested under controlled conditions on a specified government test course. For example, a tire graded 150 would wear one and a half (1 1/2) times as well on the government course as a tire graded 100. The relative performance of tires depends upon the actual conditions of their us, however, and may depart significantly from the norm due to variations in driving habits, service practices and differences in road characteristics and climate.
TRACTION A B C
The traction grades from the highest to the lowest, are A,B,and C, and they 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 is based on braking (straight ahead) traction and does not include cornering (turning) traction.
TEMPERATURE A B C
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 Vehicles Safety Standard No. 109. Grades B and A represent higher levels of performance on the laboratory test wheel than the minimum required by law. The temperature grade is established for a tire that is properly inflated and not overloaded. Excessive speed, under inflation, or excessive loading, either separately or in combination, can cause heat buildup and possible tire failure.
SPEED RATINGS
Speed rating passenger tires originated in Europe, where highway speeds can exceed 100 mph. The speed rating indicates the maximum speed a properly inflated tire will withstand for a determined time. Testing for a speed certification is conducted in a laboratory setting.
The speed rating of a tire is an indicator of the tire’s performance capability. Improving the tire’s performance capability will normally benefit the automobile’s performance. Conversely, decreasing the tire’s speed rating generally lowers the tire’s ability to contribute to the automobile’s performance.
SPEED SPEED SPEED
SYMBOL MPH KPH
M 81 130
N 87 140
P 93 150
Q 99 160
R 106 170
S 112 180
T 118 190
U 124 200
H 130 210
V 149 240
W 168 270
Y 186 300
Z OVER 149 OVER 240
