HAMPTON, Ga. - Snow was blowing around all morning Saturday at Atlanta Motor Speedway. It didn't stick, but it did force a delay in getting things started on the track.
Nationwide Series qualifying was canceled and the two practice sessions for Sprint Cup cars were combined into one long session.
Greg Biffle had the fastest lap in that session at 184.229 mph, just ahead of Roush Fenway Racing teammate Carl Edwards, Clint Bowyer, Ryan Newman and Kasey Kahne.
The car is really, really good," said Biffle, who starts 13th in Sunday's Kobalt Tools 500.
"But the race is certainly going to be a crapshoot."
Cool temperatures and a new tire combination brought to this 1.54-mile track by Goodyear combined to make things challenging in Saturday's practice.
Justin Fantozzi, Goodyear marketing manager, said the right-side tires are harder than ones used here in recent races while the construction of the left-side tires give them more grip.
Goodyear did tire test here with the new NASCAR car in August and again in December and had an open test for all teams in October. The combination being used was developed from that.
Not everyone is pleased.
"We've got such a bad right-side tire," Tony Stewart said. "After 10 years of being in the Cup Series you learn to be highly disappointed with everything that Goodyear does."
Biffle said tires will be a major factor Sunday.
"These tires don't have a lot of grip, everybody knows that, but then with the temperature going from 40 degrees to 60 and sunny, the track is going to be tremendously slick," he said.
"It's going to be like a big Darlington. You're going to have to slow down a lot in the corners and feather the gas back through it."