Goodyear Fast Facts — Michigan

NASCAR Cup Series — Race No. 23 – 200 laps / 400 miles
Michigan International Speedway (2.0-mile oval) – Brooklyn, Mich.
Fast Facts for August 5-6, 2023

Tire: Goodyear Eagle 18-inch Speedway Radials

Set limits: Cup: 1 set for practice, 1 set for qualifying and 7 sets for the race
     (6 race sets plus 1 set transferred from qualifying)

Tire Codes: Left-side — D-5186; Right-side — D-5182

Tire Circumference: Left-side — 2,263 mm (89.09 in.); Right-side — 2,279 mm (89.72 in.)

Minimum Recommended Inflation: Left Front — 22 psi; Left Rear – 24 psi;
     Right Front — 50 psi; Right Rear — 46 psi

Storyline – Combatting heat at Michigan: Unlike the high tire wear track at last weekend’s race at Richmond Raceway, the surface at Michigan International Speedway is relatively smooth with a lot of grip.  The high level of grip leads to high speeds and greater tire temperatures.  Tires that do not wear much on their own tend to build heat over the course of a run.  When a race tire wears, the thinning tread allows heat to dissipate, making it run cooler and at a more optimal level.   Goodyear designs the tire set-up for Michigan with that in mind, combatting the lack of wear with less gage (tread thickness) in the tread.
     “Tire heat works against what teams are trying to accomplish in gaining as much grip and as much speed as possible,” said Greg Stucker, Goodyear’s director of racing.  “Michigan has a relatively smooth track surface and produces some of the highest speeds on the NASCAR circuit.  That, combined with the lack of wear that the track surface generates, causes heat to build in the tires and creates a challenge for the teams to keep the proper balance under the car.”

Notes – Cup teams move to popular left-side tire at Michigan: Being on 18-inch bead diameter tires, NASCAR Cup teams will run a different tire set-up than those in the Xfinity Series at Michigan this week . . . this is the same right-side tire code that Cup teams ran at Michigan last season, but with a different left-side code . . . compared to last year’s left-side, this year’s version features a construction update that has been rolled into many tracks . . . these teams have run this left-side at five tracks already this season – Auto Club, Las Vegas, Kansas, Nashville and Pocono . . . 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.

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GOODYEAR TIRE NOTES

NASCAR Xfinity Series – Race No. 21 – 125 laps / 250 miles
Michigan International Speedway (2.0-mile oval) – Brooklyn, Mich.
Fast Facts for August 4-5, 2023

Tire: Goodyear Eagle 15-inch Speedway Radials

Set limits: Xfinity: 5 sets for the event

Tire Codes: Left-side — D-6110; Right-side — D-6112

Tire Circumference: Left-side — 2,225 mm (87.60 in.); Right-side — 2,250 mm (88.58 in.)

Minimum Recommended Inflation: Left Front — 19 psi; Left Rear – 19 psi;
     Right Front — 52 psi; Right Rear — 48 psi

Notes – Xfinity teams return to Michigan on 2022 tire set-up: Being on 15-inch bead diameter tires, NASCAR Xfinity Series teams will run a different tire set-up than those in the Cup Series at Michigan this week . . . this is the same combination of left- and right-side tires that Xfinity teams ran at Michigan last season . . . these teams ran this same tire set-up at Las Vegas earlier this season, and will run it again at Kansas to end the regular season and Texas in the playoffs . . . as on all NASCAR ovals greater than one mile in length, teams are required to run inner liners in all four tire positions at Michigan . . . air pressure in those inner liners should be 12-25 psi greater than that of the outer tire.

Follow us on Twitter: @GoodyearRacing.

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