NASCAR Cup Series — Race No. 27 — 367 laps / 501 miles Darlington Raceway (1.366-mile oval) — Darlington, S.C.
Fast Facts for September 2-3, 2023
Tire: Goodyear Eagle 18-inch Speedway Radials
Set limits: Cup: 1 set for practice, 1 set for qualifying and 13 sets for the race (12 race sets plus 1 set transferred from qualifying)
Tire Codes: Left-side — D-5184; Right-side — D-5190
Tire Circumference: Left-side — 2,263 mm (89.09 in.); Right-side — 2,279 mm (89.72 in.)
Minimum Recommended Inflation: Left Front — 20 psi; Left Rear — 22 psi; Right Front — 48 psi; Right Rear — 44 psi
Storyline — NASCAR Cup playoffs open at high-wear Darlington: Pit road will be a busy place at Darlington Raceway this Sunday. With the abrasive track surface, teams will have 13 sets of tires for the Southern 500 — tied with the Coca-Cola 600 for the most sets allotted for a NASCAR Cup race. Lap times slowed down three seconds over the course of a fuel run in the spring race at Darlington, with significant fall-off after just a few laps. That will keep pit crews on their toes throughout the 367-lap race, with teams taking four tires at every opportunity. That means if teams use each of their 13 sets, they will pit an average of once every 28 laps. For drivers, tire management will be important, with those that are easier on their tires early in a run will fall off less and gain track position later in the run.
“Darlington has perhaps the most abrasive racing surface of all the tracks we run on in NASCAR, and that means tires will wear heavily,” said Greg Stucker, Goodyear‘s director of racing. “Four-tire pit stops will be the call all day, so pit crews will be an important factor in the race. The great thing at Darlington is that fans will get to see a lot of passing throughout the field with some drivers being able to manage their tires better than others, meaning that those who are able to work the throttle so as not to abuse their tires early in a run, will be able to pass a lot of cars later in a run.”
Notes — Cup teams return to Darlington on spring tire set-up: Being on 18-inch bead diameter tires, NASCAR Cup teams will run a different tire set-up than those in the Xfinity Series at Darlington this weekend . . . this is the same combination of left- and right-side tires Cup teams ran at this track and on the Charlotte oval in May . . . Cup teams will run this same tire set-up at Homestead later in the playoffs . . . this right-side tire code has also been run with a different left-side code at Auto Club, Kansas, Las Vegas, Nashville and Pocono earlier this season . . . with this 18-inch tire, and its lower profile sidewall, NASCAR Cup cars will not run inner liners in any of their tires in 2023.
NASCAR Xfinity Series — Race No. 25 — 147 laps / 201 miles Darlington Raceway (1.366-mile oval) — Darlington, S.C.
Fast Facts for September 2, 2023
Tire: Goodyear Eagle 15-inch Speedway Radials
Set limits: Xfinity: 6 sets for the race
Tire Codes: Left-side — D-6106; Right-side — D-6130
Tire Circumference: Left-side — 2,225 mm (87.60 in.); Right-side — 2,250 mm (88.58 in.)
Minimum Recommended Inflation: Left Front — 18 psi; Left Rear — 18 psi; Right Front — 48 psi; Right Rear — 44 psi
Notes —Fourth straight Darlington race on this tire set-up for Xfinity teams: Being on 15-inch bead diameter tires, Xfinity teams will run a different tire set-up than those in the Cup Series this weekend . . . this is the same combination of left- and right-side tires that these teams ran at Darlington in May and twice last season . . . Xfinity teams will also run this same tire set-up at Homestead in October . . . additionally, these teams have run this left-side tire code at Auto Club, Bristol, Dover and Pocono, and this right-side code on the Charlotte oval, earlier this season . . . as on all NASCAR ovals greater than one mile in length, Xfinity teams are required to run inner liners in all four tire positions at Darlington . . . air pressure in those inner liners should be 12-25 psi greater than that of the outer tire.
— Goodyear Racing —