The new radial tires increase forward and reverse traction by up to 18 percent, because the larger footprint reduces wheel slip, says product manager David Ashby. Other benefits include increased tire life of up to 33 percent and a harmonically noise-treated tread design that reduces cab noise and road vibration. The new 320/80R18 DuraForce AT-R is approved for rim widths of 9.00 and 10.00 inches, while the 340/80R18 DuraForce AT-R is approved for rim widths of 10.00 and 11.00 inches.