Set limits: Cup: 3 sets for practice, 1 set for qualifying and 8 sets for race; Xfinity: 6 sets for the event
Tire Codes: Left-side — D-4864; Right-side — D-4866
Tire Circumference: Left-side — 2,227 mm (87.68 in.); Right-side — 2,245 mm (88.39 in.)
Minimum Recommended Inflation: Left Front — 14 psi; Left Rear — 14 psi; Right Front — 32 psi; Right Rear — 30 psi
Storyline – Cup teams under (air) pressure at Phoenix with new rules package: Phoenix is one of the more unique tracks on the NASCAR circuit, from its three distinct corners, to its relative lack of banking, to its speedway characteristics despite being just one mile in length. It is different from other short tracks in that aerodynamics come more into play. And that may be even more of the case in 2019 as the NASCAR Cup teams will be on a high downforce, high horsepower rules package for the first time this season. That combination will result in higher speeds and increased tire loading, making the use of the proper level of air pressure an important factor in arriving at car set-ups.
“Cup teams will be under a new rules package this week at Phoenix, with all the new aerodynamic elements, but with more horsepower than they’ve had over the past couple weeks,” said Greg Stucker, Goodyear’s director of racing. “When we tested on this package at Phoenix last fall, teams were considerably faster than we’ve seen in recent years. With the extra downforce versus the 2018 rules package, much of that speed comes through the corners, which generates higher loading on the tires. Teams will need to be mindful of our recommended air pressures as they develop their set-ups to optimize grip. Running below our minimums can cause the sidewall of the tire to flex more and over-deflect, generating more heat, higher wear and fall-off, and even damaging the tire to the point of air loss. Finding that balance will be key.”
Notes – Brand new tire set-up debuts at Phoenix: Teams in both the Monster Energy NASCAR Cup and Xfinity Series will run the same tire set-up at Phoenix this week . . . this is the first time either of these two Goodyear tire codes will be run . . . compared to what Cup and Xfinity teams ran at Phoenix last November, this left-side tire features a construction update that Goodyear will be rolling into many tracks this season, while this right-side tire features a compound change designed to introduce more tire wear and run cooler . . . Phoenix is the only track at which these either of these two tire codes are scheduled to be run . . . this tire combination came out of a Goodyear test at Phoenix last October 2-3 . . . drivers participating in that test were Denny Hamlin, Matt Kenseth, Kyle Larson and Paul Menard . . . as on most NASCAR ovals one mile or less in length, teams will not run liners in their tires at Phoenix.
