Both the Michelin Energy MXV4 S8 and the Michelin Primacy MXV4 are all-season touring tires featuring twin steel belts and spiral-wrapped polyamide cord. The Energy MXV4 S8 is designed for sport sedans and sport coupes. The Primacy MXV4 is designed for standard sedans and coupes as well as minivans and SUV crossovers.
Green X is Michelin's way of designating tires that the company guarantees meet a standard of energy efficiency that is among the highest in the tire's category. The designation is on a case-by-case basis by model and size. This means that not all sizes of the same model of tire are necessarily Green X. According to Michelin, this is because reducing rolling resistance to lower fuel consumption cannot be done on all tires without, in some cases, compromising traction and tread wear.
The Uniform Tire Quality Grade is a standard issued by the National Highway Traffic Safety Administration and is printed on the side of all tires sold in North America. The numeric portion of the UTQG is the tread wear rating. The higher the number, the longer the tread is expected to last.
The Energy MXV4 S8 has a symmetric block tread with offset diagonal and shoulder intermediate blocks. The internal structure is a rounded casing shape that equalizes footprint pressure, reducing rolling resistance and increasing tread life. The Energy MXV4 S8 is available in 13 sizes. All are rated as Green X. The Uniform Tire Quality Grade is 440AA for 11 sizes. The special Mercedes version of the 205/55, the 205/55R16 SL Mercedes, has a tread wear rating of 240AAA. The 225/50R17 has a tread wear rating of 420AA. Sizes range from 195/65R15 to 245/45R19, with prices from approximately $125 for the 195/65 to the $250 range for the 245/45 as of January 2011.
The Michelin Primacy MXV4 has a symmetric tread design with notched shoulders, continuous center ribs and intermediate independent blocks. It comes in 36 sizes, only five of which are designated as Green X. Tread wear ratings are significantly higher than for the MXV4 S8. Where the top UTOG rating for the MXV4 S8 is 440AA, thirty-one of the thirty-six sizes of the MXV4 have a tread rating of 660AA. The five that do not are still rated as having longer wearing treads (500AA) than the highest rated MXV4 S8 (440AA). MXV4 sizes range from 185/65R15 to 245/45R20, with prices, in January 2011, from approximately $105 for the smallest size, up to the $280 range for the 245/45.
