NASCAR Sprint Cup Series, Race No. 25 – Bojangles' Southern 500
Darlington Raceway (1.366-mile oval) – Darlington, S.C., September 4-6, 2015
Tire: Goodyear Eagle Speedway Radials
Set limits:7 sets for practice/qualifying, and 12 sets for
the race
Tire Codes: Left-side, D-4650; Right-side, D-4646
Tire Circumference: Left-side, 87.56 in. (2,224 mm); Right-side,
88.43 in. (2,246 mm)
Minimum Recommended Inflation: Left Front, 22 psi; Left Rear, 20 psi;
Right Front, 52 psi; Right Rear, 48 psi
Teams in the NASCAR Sprint Cup and Xfinity Series will run completely different tire set-ups at Darlington this weekend.
In Sprint Cup, this set-up features the left-side tire code (D-4650) run at Indianapolis and the right-side tire code (D-4646) run at Kentucky earlier this summer.
Compared to what was run at Darlington last year – and in response to NASCAR’s lower downforce package – this left-side features construction and mold shape changes, while this right-side features a compound change for more grip.
This tire set-up came out of a Goodyear test at Darlington on June 30, after the
new rules package was announced. Drivers participating in that test were Matt Kenseth, Brad Keselowski and Tony Stewart.
As on all NASCAR ovals greater than one mile in length, teams are required to
run inner liners in all four tire positions at Darlington with air pressure in those inner liners being 12-25 psi greater than that of the outer tire.
Throwback Tires: In keeping with NASCAR’s throwback efforts and the return of the Southern 500 to its traditional spot on the schedule on Labor Day weekend, the tires run at this weekend’s Darlington races will feature different sidewall markings, replacing the yellow Goodyear lettering that became standard in 1992 is a white, stencil-look design that harkens back to the mid-1970s.
