NASCAR Cup Series — Race No. 18 — 100 laps / 220 miles
Chicago street course (2.2-mile road course) — Chicago, Ill.
Fast Facts for July 1-2, 2023
Tire: Goodyear Eagle 18-inch Road Course Radials
Set limits: 2 sets for practice, 1 set for qualifying and 6 sets for the race (5 race sets plus 1 set transferred from qualifying)
Tire Codes: Left-front & Right-rear — D-5212; Right-front & Left-rear — D-5213
Tire Circumference: 2,275 mm (89.57 in.)
Minimum Recommended Inflation: Left Front — 22 psi; Right Front — 20 psi; Left Rear — 17 psi; Right Rear — 17 psi
Storyline — Taking it to the streets: Going to a new race course is difficult, but not being able to test on that surface adds another level. That is what faces NASCAR and Goodyear this weekend on the Chicago street course. Goodyear had to rely on surface characterizations, as well as its history of designing tires to determine what would work. After getting the course layout, Goodyear sent an engineer to Chicago to measure the coefficient of friction at multiple locations. The tire maker then took that information, along with the estimated top speeds in each of the corners based on modeling done by the teams, and compared it to its database of other tracks NASCAR has raced on. All that confirmed that Goodyear‘s standing road course set-up would work well on this course.
“This is an exciting week for NASCAR, with this event on the streets of Chicago,” said Greg Stucker, Goodyear‘s director of racing. “We had to take somewhat of a non-traditional tact in coming up with our tire set-up because we obviously couldn‘t test on the course. We relied on some surface characterizations we gathered on the streets on different parts of the course. We also worked with teams that had done some extensive modeling of the complete circuit. After assessing all of that — the street surfaces and the expected speeds — we determined that the road course set-up that teams are very familiar with would be able to handle the demands of the circuit and be the best option.
Notes — Chicago aligned with other NASCAR Cup road courses: Being on 18-inch bead diameter tires, NASCAR Cup teams will run a different tire set-up than those in the Xfinity Series on the Chicago street course this weekend . . . this tire set-up has been run by Cup teams at COTA and Sonoma already this season . . . these two tire codes have identical constructions and compounds, but they carry different codes because they are mounted directionally based on the corner of the car to keep the tread splice ‘closed‘ under braking into the corners or acceleration off the corners . . . with this 18-inch tire, and its lower profile sidewall, NASCAR Cup cars do not run inner liners in any of their tires.
Wet Weather Tires — Goodyear brings white-lettered “wets” to Chicago: Goodyear will bring its 18-inch wet weather radials to the Chicago street course for use by teams in the NASCAR Cup Series, should NASCAR decide that conditions warrant . . . the tread pattern on this tire is based on Goodyear‘s Eagle Supercar 3 consumer tire . . . NASCAR Cup teams last ran a wet weather tire in competition at the All-Star race at North Wilkesboro in May, and the last time on a road course at Watkins Glen in August 2022 . . . in addition to the obvious difference of a tread pattern versus Goodyear‘s dry weather “slick” tires, the “Goodyear” and “Eagle” lettering on the sidewalls of the wet weather tires is white, not the standard yellow.
— Goodyear Racing —
