Time to see if COT will take to the heavy air in Phoenix

It's all about the air, the warm stuff that blows out of the Sonoran Desert and settles over the Valley of the Sun. It's dry, hot, and this time of year, full of pollen from blooming ash and olive trees. And it presents the next challenge for NASCAR's Car of Tomorrow, which competes at Phoenix International Raceway on Saturday night.

After a pair of opening races on short tracks, the COT makes its first foray onto a larger speedway when the Nextel Cup Series rolls into the 1-mile oval in Avondale, Ariz. After weeks spent fretting over brakes, damage, exhaust systems and protective foam with a strange propensity to melt, the focus now turns to the air wafting down from the Estrella Mountains, and how the boxier vehicles will handle within it.

Some find car change challenging

Implementing the Car of Tomorrow into NASCAR over a three-year period means drivers have to go back-and-forth between two different cars. For some drivers, the switch is more challenging than they anticipated.

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Phoenix poses the first real trial of the COT's aerodynamics, something only tangentially tested on the half-mile circuits at Bristol and Martinsville. And it should provide a glimpse of how the vehicle will fare on even bigger tracks, slated for the later stages of the COT's rollout.

"Bristol and Martinsville were good tracks for this car to be introduced," said points leader Jeff Gordon. "They're short tracks, and aerodynamics don't play much of a role in the handling of the car. It allowed us to understand the inspection process a little bit better, and gave us a chance to learn what areas we can work on to gain mechanical grip. I think this race will give us a much better idea of where we are with the Car of Tomorrow. It's a lot faster track, where aerodynamics are much more of a factor."

Bristol and Martinsville offered what may prove to be an inauspicious preview. Even on the short tracks, it was evident that drivers were having a more difficult time passing one another -- no surprise on the smaller circuits, but apparently exacerbated by the new car's aerodynamics. Out front, in clean air, the car seemed to soar. In traffic, it was another story.

And two of the most hated words in Nextel Cup racing -- aero push -- began getting tossed around again.

"The biggest concern for me is going to be how aero tight we're going to be, how hard passing is going to be," Denny Hamlin said. "We know from testing at Richmond that you can't even get close to anybody before it pushes. You can be three-tenths [of a second] faster, and all of the sudden you're three-tenths slower. It's a concern for us, but we've just got to work through it."

Teams tested the COT on the .75-mile track at Richmond during the off week following the Martinsville race. Some team will take setups from that test into the Phoenix event, despite the aerodynamic differences the two facilities present. Phoenix native J.J. Yeley believes the timing of the Saturday night race will give drivers more grip to work with than they had in the first two COT events. (Continued)