NASCAR Cup Series — Race No. 34 – 267-laps / 400.5 miles
NASCAR Xfinity Series – Race No. 31 — 200 laps / 300 miles
Kansas Speedway (1.5-mile oval) – Kansas City, Kan.
Fast Facts for October 23-24, 2021
Tire: Goodyear Eagle Speedway Radials
Set limits: Cup: 9 sets for the race; Xfinity: 5 sets for the race
Tire Codes: Left-side — D-4942; Right-side — D-4986
Tire Circumference: Left-side — 2,225 mm (87.60 in.); Right-side — 2,248 mm (88.50 in.)
Minimum Recommended Inflation: Left Front — 18 psi; Left Rear — 18 psi; Right Front — 50 psi; Right Rear — 48 psi
Storyline – While grouped with “smooth” tracks, Kansas will wear tires: While the Goodyear tire set-up for Kansas Speedway is similar to what is run at some of the smoother track surfaces on the NASCAR circuit – Las Vegas Motor Speedway, Michigan International Speedway and Texas Motor Speedway – teams will see some tire wear this weekend. Kansas was repaved back in 2012 and is subject to the hot summers and cold winters of Kansas, which has aged the track over time. Teams can expect to see approximately a second-and-a-half of fall-off in lap times over the course of a fuel run, so tire management can be a bit of a factor.
“Kansas poses an interesting challenge for teams in that it is still considered a relatively smooth track surface, yet it has begun to wear tires over the last several races at the track,” said Greg Stucker, Goodyear’s director of racing. “We work hard to design our tread compounds to match up with a track surface and we definitely have a compound, specifically on the right-side, that will also introduce wear at Kansas. We just ran this right-side tire at Texas last week, and Cup teams ran this same set-up at Kansas earlier in the season, so they are very familiar with what to expect. The wear we get at Kansas is a good thing. When tires shed rubber as they wear, heat is allowed to dissipate through the tread and run cooler and at a more optimal grip level.”
Notes – Cup returns to Kansas on existing tire set-up; change to Xfinity right-side tire compared to fall ‘20: Teams in both the NASCAR Cup and Xfinity Series will run the same tire set-up at Kansas this weekend . . . this is the same combination of left- and right-side tires that Cup teams ran at this track last October and again this May . . . for Xfinity, they ran this left-side code with a different right-side at Kansas last October . . . compared to what Xfinity ran last season, this right-side tire features a compound change for more grip . . . this left-side tire code was run on the Charlotte oval and at Nashville, while this right-side code has been run at Las Vegas, Michigan and Texas in 2021 . . . as on all NASCAR ovals greater than one mile in length, teams are required to run inner liners in all four tire positions at Kansas . . . air pressure in those inner liners should be 12-25 psi greater than that of the outer tire.
— Goodyear Racing —