NASCAR tyre supplier Goodyear has warned Cup Series teams to obey its tyre pressure advice at Phoenix this weekend given the higher speeds likely under the 2019 rules.
The full higher downfore and increased horsepower rules package - designed to increase overtaking - will be used for the first time at Phoenix.
That combination will result in higher speeds and increased tyre loading, and Goodyear racing director Greg Stucker warned that teams tempted to run lower than advised pressures for set-up reasons risk both higher wear and potential deflations.
"When we tested on this package at Phoenix last fall, teams were considerably faster than we've seen in recent years," said Stucker.
"With the extra downforce versus the 2018 rules package, much of that speed comes through the corners - which generates higher loading on the tyres.
"Teams will need to be mindful of our recommended air pressures as they develop their set-ups to optimise grip.
"Running below our minimums can cause the sidewall of the tyre to flex more and over-deflect, generating more heat, higher wear and fall-off, and even damaging the tyre to the point of air loss.
"Finding that balance will be key."
Goodyear is bringing new left and right-side tyres to Phoenix for both the Cup and Xfinity series.
The left-side tyre features a construction update that Goodyear will be rolling out for many tracks this season, while the right-side tyre features a compound change designed to introduce more tyre wear and run cooler.
Phoenix is the only track at which these two tyre types will be used together this year.
The combination came out of a Goodyear test at Phoenix last October involving Denny Hamlin, Matt Kenseth, Kyle Larson and Paul Menard.