Current 37+ 315 60 20 Tires. Designed to provide exceptional performance and life in linehual drive applications 2 ยทยทยท with the production of all steel radial tires of 3.1 millon pcs/ year,semi steel radial tires (pcr) of 15 million pcs/year and otr tires of 20 thousand. Get the best deal for 315/60/20 car & truck tires from the largest online selection at ebay.com. The circumference is 109.5 and they have 578 revolutions upsizing wheels or tires?