Toyo Proxes 4
Toyo Tires has proven performance credentials. It manufactures the spec tires for SPEED World Challenge, Proxes T1-S in Touring and Proxes RA-1 in GT class. Both will be on Proxes RA-1 for 2004. Toyo is also the official tire of the NHRA Summit Sport Compact Drag Racing series. Toyo's racing involvement underlines the performance capabilities of its products.
Toyo is also the title sponsor of Hot Import Nights, which it believes to be the most accurate representation of Gen X/Y customers and automotive lifestyle events. Further, it operates the Take it to the Track program to discourage illegal street racing.
Thus, I was excited when Toyo announced an all-new performance tire, the Proxes 4. It is an all-season, high-performance tire aimed at plus-fitment applications on sport compact cars, sports sedans and coupes.
The internal construction is very similar to that of the Proxes T1-S, which has shown its performance capabilities in SPEED World Challenge. It starts with a jointless bead wire and uses a hard-bead filler compound in the sidewall for lateral stiffness. The casing is polyester, followed by two full-width steel belts and jointless edge and cap plies. The latter consist of a continuous length of nylon cord tape to improve uniformity.
The tread design was styled to be attractive as well as functional. It has a solid center rib for stability and steering response. Shoulder tread blocks are paired to support each other and better withstand cornering and braking forces. Tread blocks use a multi-wave sipe, with a zig-zag pattern rather than a smooth channel. Under load, the sipes interlock, allowing the tread blocks to support each other. The result is less deformation and heating of the compound and greater durability.
Wet performance is obtained through use of a W-shaped tread pattern and "Generation S" silica compound. Computer simulation was used to determine the optimum balance between water evacuation capability and remaining tread surface area in contact with the pavement. Silica compounds have better wet traction and longer life than pure carbon compounds. The paired shoulder blocks and multi-wave sipes also reduce tread deformation when rolling straight, enhancing tire life.
The Proxes 4's UTQG tread wear rating is 300. It has M+S designation, but that is basically a measure of void ratio, not of design for mud and snow conditions. Sizes range from 195/50-15 to 245/35-19. Speed ratings are V (up to 149 mph) for smaller sizes and W (up to 168 mph) for all 17- to 19-in. sizes.