Set limits: Cup: 3 sets for practice, 1 set for qualifying and 12 sets for the race (11 race sets plus 1 set transferred from qualifying or practice); Xfinity: 8 sets for the event
Tire Codes: Left-side — D-4928; Right-side — D-4960
Tire Circumference: Left-side — 2,225 mm (87.60 in.); Right-side — 2,252 mm (88.66 in.)
Minimum Recommended Inflation: Left Front — 18 psi; Left Rear — 18 psi; Right Front — 45 psi; Right Rear — 42 psi
Storyline – Challenges abound at Auto Club: There are several factors that put tires front-and-center at this week’s stop on the NASCAR Cup schedule, Auto Club Speedway. First, the track surface at Fontana is extremely worn and abrasive, so tire wear is a reality and tire management will come into play. Second, to go along with that worn surface, Cup teams will have 12 sets of tires for race day. With teams likely to take four tires at every opportunity, the pit crews will be busy and have a major impact on the race. Third, in an attempt to gain maximum grip, teams often go below Goodyear’s minimum left-side tire pressure recommendations in a risk vs. reward trade-off. Running low air, especially early in a run before pressures build, can cause the sidewall of the tire to over-deflect, creating damage that will lead to air loss later in a run.
“Racing at Fontana presents multiple challenges for NASCAR teams,” said Greg Stucker, Goodyear’s director of racing. “The track surface is very abrasive, and teams will take four tires all day long. With the Cup teams having 12 sets of tires for a 200-lap race, they will make full use of their compliment and stay busy on pit road throughout. We have rolled in our latest construction updates into this tire set-up, so these tires are well tuned to the loading demands of the high downforce package. Having said that, teams still need to be mindful of our minimum recommended air pressures, specifically on the left-side. While teams sometimes like to go below our recommendation as a tuning tool to gain grip, a lot of damage can be done on low pressures at the beginning of a run that can hurt the structure of the tire. Our engineers will be working with teams all weekend to help them, should they be getting a little too close to the edge.”
Notes – Updated construction on both left-side and right-side at Auto Club: Teams in both the NASCAR Cup and Xfinity Series will run the same tire set-up at Auto Club Speedway this week . . . while this is the first time they have run either of these two Goodyear tire codes at Fontana, they did run this left-side code at Chicagoland, Darlington and Homestead last year . . . compared to what was run at Fontana last year, both this left-side and right-side tire feature construction updates to bring these tires in line with what is run at other speedways . . . this right-side tire is a multi-zone tread tire, featuring two distinct tread compounds on the same tire — one for heat and wear resistance on the inboard two inches of the tread (Endurance Zone) and one for grip on the outboard 10 inches (Traction Zone) . . . as on all NASCAR ovals greater than one mile in length, teams are required to run liners in all four tire positions at Fontana . . . air pressure in those inner liners should be 12-25 psi greater than that of the outer tire.