Despite running breathtaking record speeds at Michigan International Speedway, Jimmie Johnson said his car felt comfortable.
Greg Biffle, on the other hand, said, "I think we're approaching some safety concerns at the speeds we're going -- I don't know that we're quite there yet, though."
In Thursday morning's test session at the recently resurfaced two-mile track, Mark Martin topped the speed chart with a lap at 201.069 mph in race trim. All told, 39 drivers surpassed Ryan Newman's August 2005 track qualifying record of 194.232 mph.
Though both drivers and NASCAR officials expect speeds to decline throughout the weekend -- because of hotter conditions and Hoosier rubber that will adhere to the track in Friday's ARCA race -- NASCAR vice president of competition Robin Pemberton wouldn't rule out a qualifying lap in excess of 200 mph during Saturday time trials.
That hasn't happened since Bill Elliott put his Ford on the pole at Talladega at 203.827 mph in July 1987, the last superspeedway race before NASCAR mandated restrictor plates at Talladega and Daytona to limit horsepower and reduce speeds.
Restrictor plates won't be a consideration at Michigan, according to Pemberton.
"What we saw this morning is the best shape the track will be in," Pemberton said during a break between Thursday's test sessions. "As they continue to run and lay down rubber, and the other series (Nationwide and ARCA) that will run here throughout the weekend, the grooves will widen out, but the pace will slow down.
"It was nice to see the speeds this morning. Maybe qualifying will get back to there -- maybe. But for the most part, it'll continue to slow down from here."
From Biffle's point of view, that's probably a good thing.
"We're certainly pushing the envelope with the extra speed," he said. "The wall still isn't going to move when you get there."
To Johnson, the stability of the cars counterbalances the speeds they are running.
"It's been quite a rush for the drivers," said the five-time champion. "To be on the track and to go this fast and to run an average lap time of over 200 mph -- you certainly feel the speed, and the comfort is there . . .
"I don't have any concerns about the speeds. Granted, I haven't seen one hit the wall yet to see how the car reacts with the SAFER barrier at this pace, (but) at least the balance that we have under our racecar right now has been very comfortable to drive."
Speeds didn't taper off Thursday afternoon. Tony Stewart paced the session at 201.896 mph, followed by Biffle (201.556 mph) and Kurt Busch (201.174 mph), back from a 10-day suspension that kept him out of the Pocono race.
Dale Earnhardt Jr., whose last victory came in the June race at Michigan in 2008, was fourth fastest in the morning and fifth after lunch, posting his top speed of 200.658 mph in the afternoon.