Teams in all three NASCAR series will run the same tire set-up this week . . . this left-side tire code (D-4392) has been run by all NASCAR teams at Chicagoland since 2011 . . . this right-side tire code (D-4618) was run at Chicagoland by Sprint Cup teams only last September . . . Xfinity teams switched to this right-side tire at this track earlier this season, while this is the first Chicagoland race with this right-side for Camping World Truck teams . . . this right-side tire employs Goodyear's multi-zone tread technology, which combines two distinct tread compounds on the same tire — one on the inboard two inches of the tread for endurance and heat resistance, and one on the outboard 10 inches of the tread for traction . . .
All these teams ran this same combination of left- and right-side tires at Texas earlier this season . . . they are scheduled to run it again at both Texas and Homestead at the end of the season . . . this tire combination was confirmed for Chicagoland in a tire test at the track on July 13-14 . . . drivers participating in that test were Dale Earnhardt Jr., Sam Hornish, Martin Truex Jr. and J.J. Yeley . . . as on all NASCAR ovals greater than one mile in length, teams are required to run inner liners in all four tire positions at Chicagoland . . . air pressure in those inner liners should be 12-25 psi greater than that of the outer tire. Goodyear