The g-Force R1 S (S for Sprint) radial is BFGoodrich's Racetrack & Autocross Only special-use DOT-legal racing tire developed for the drivers of prepared vehicles looking to run their quickest times in autocross, sprint race and time attack events. Offering more ultimate dry grip, g-Force R1 S tires come up to temperature quicker and provide more grip in cooler ambient temperatures on tracks that are easier on tires (compared to the standard g-Force R1). However, the g-Force R1 S will wear quicker than the standard g-Force R1 tires and are not as well suited for extremely hot days.While g-Force R1 S radials meet DOT requirements, they are not appropriate for highway use. g-Force R1 S radials are not recommended for driving in wet conditions where standing water is present and there is the risk of hydroplaning; drivers should drive cautiously at reduced speeds if they encounter these conditions. And like all Racetrack & Autocross Only tires, g-Force R1 S radials are not intended to be driven in near-freezing temperatures, through snow or on ice. It's also essential these tires be stored indoors at temperatures maintained above 32 degrees F.The g-Force R1 S use an enhanced competition tread compound molded into a symmetric, non-directional, semi-slick tread design with just 4/32" of beginning tread depth eliminating the need for shaving. Rubber bridges are molded repeatedly across the two DOT-required circumferential grooves to promote even wear and provide slick-like performance. While the tires require minimal scuffing, heat cycling is recommended to further enhance consistency and wear. The tread compound warms up quickly to provide predictable grip that is forgiving and easy to drive at the limit. Featuring a symmetric, semi-slick tread design allows the g-Force R1 S to rotate in different directions and be used at different vehicle wheel positions to maximize treadlife. The tire's internal structure includes twin steel belts reinforced by a spirally wrapped polyamide cord on top of a two-ply nylon cord casing.The g-Force R1 S cannot be mixed with g-Force R1 tires on a vehicle. Related Information: Competition Tire Heat Cycling Service | Storing Track & Competition DOT Tires in Cold Temperatures | The g-Force Family Control Manual (PDF)