Kahne's top lap of 193.771 mph was faster than the track record of 193.708 mph, set by Greg Biffle in qualifying for the Bank of America 500 in October. However, Kahne's speed won't count as an official record because it didn't occur during a race weekend.
Even so, Kahne and other drivers agreed that the new cars will prove faster than their predecessors.
"I was trying to think, if we were in the old car in race trim this time of year, if I could go as fast as I went this morning. I really don't think I could," Kahne told reporters. "So I'm thinking there's probably three- or four-tenths (of a second) there. That's just a guess, but I would say three- to four-tenths that we're running faster in this car than we would in that (one). ... I just think this car goes around the corner quicker."
However, the machinery might not have been the only factor in the day's speeds, which were significantly faster than Tuesday's top marks, NASCAR.com reported. Dale Earnhardt Jr.'s crew chief, Steve Letarte, pointed to Wednesday's temperatures that hovered in 40s, colder than on a usual race weekend.
"You see that here a lot," Letarte said of the weather affecting lap times. "We come here in the day and practice at a 30 flat or 29.5 range, and yet we qualify at a 28 flat. I think weather is probably the primary contributor ... but I don't think we'll really know until we get to real race tracks on real race weekends."
Joey Logano told reporters, "With it being cooler out today, we're going even faster, so you take all of that with a grain of a salt. I think speeds will be up. I think there is definitely some possibility for track records being broke, but we have to kind of wait and see what the package is going to be when it's all said and done here from NASCAR."
Denny Hamlin crashed when his car's upper control arm broke, ending his day early. Rain later cut short the practice session.
NASCAR has two more testing sessions planned for the 2013 cars: Jan. 10-12 at Daytona International Speedway and Jan. 17-18 back at Charlotte.