Early in NASCAR Cup Series final practice Saturday, four drivers had problems with flat left-rear tires.
Ty Gibbs experienced that issue after setting the fastest lap in Group 1 at 180.144 mph (29.976 seconds).
As practice proceeded, Shane van Gisbergen, Brad Keselowski and Chase Briscoe all had flat left-rears during the course of their runs.
The current left-side tire code is being used for the first time at Kansas, featuring a new compound designed to produce more wear and increased lap time fall-off.
However, Cup teams have already run the same tire combination in use at Kansas at Las Vegas, Homestead-Miami, Darlington and Texas—without similar incidents.
Teams typically run their tire pressures below Goodyear’s recommendations to maximize grip and speed as the heat in the tires builds up.
“We’re all just pushing the cars to the limit,” Keselowski said. “We didn’t think it was that close, but we’ll work on it and get it better for Sunday.”
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