Tire: Goodyear Eagle Speedway Radials
Set limits: Cup: 3 sets for practice, 1 set for qualifying and 11 sets for race; Xfinity: 8 sets for the event
Tire Codes: Left-side — D-4834; Right-side — D-4838
Tire Circumference: Left-side — 2,227 mm (87.68 in.); Right-side — 2,251 mm (88.62 in.)
Minimum Recommended Inflation: Left Front — 19 psi; Left Rear — 19 psi; Right Front — 45 psi; Right Rear — 42 psi
Storyline – Racing at Fontana puts emphasis on “air” and “wear”: The worn surface at Auto Club Speedway puts a premium on grip and stability needed for corner entry. Teams are particularly hard on their left-side tires as they challenge the air pressure recommendation to try to maximize grip, and that will be more so this season as the NASCAR rules package puts more downforce on the Cup cars this season. High wear also makes tire management come into play at Auto Club, which is also a multi-zone tread tire track. Goodyear held a tire test at this track in January in preparation for this race.
“Fontana presents multiple challenges for teams as far as tires are concerned,” said Greg Stucker, Goodyear’s director of racing. “First, with NASCAR’s new rules package and more downforce on the Cup cars, observing our minimum recommended air pressures becomes even more important. Teams are always looking to add grip at Fontana, and one way they do that is by dropping the air pressures, particularly in the left side tires. While we have made some updates to our constructions over the past several seasons, low air can still cause problems. Going low on air causes the sidewall of the tire to over-deflect early in a run and weaken its structure, creating a potential problem later. Secondly at Fontana, you have a track surface that wears tires heavily. The fall-off is around three seconds a lap over the course of a fuel run, so tire management will come into play all day. Tire wear generally does two things for the fans — enhance the quality of the racing by creating more passing, and bring the pit crews more into play and emphasize the team aspect of our sport as teams take four tires every chance they get.”
Notes – Goodyear updates constructions on both sides for Fontana: Teams in both the Monster Energy NASCAR Cup and Xfinity Series will run the same tire set-up at Auto Club Speedway this week . . . while teams in both of these series ran this left-side tire code at Darlington last year, this is the first time they have run this right-side tire code . . . compared to what was run at Auto Club 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 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) . . . this tire set-up came out of a Goodyear test at Auto Club on January 9-10 . . . drivers participating in that test were Joey Logano, Daniel Suarez and Martin Truex Jr. . . . as on all NASCAR ovals greater than one mile in length, teams are required to run liners in all four tire positions at Auto Club . . . air pressure in those inner liners should be 12-25 psi greater than that of the outer tire.