Keselowski, who captured the 2010 NASCAR Nationwide Series championship on Saturday afternoon at TMS, was forced into a backup car following a spin during Friday morning's practice session. He was able to turn in a lap of 28.476 seconds, or 189.633 miles per hour, during qualifying, which placed him 36th on the starting grid. As the race began, Keselowski radioed to crew chief Jay Guy that his car was loose-handling getting into the high-speed TMS corners. An early lap 12 caution gave Guy an opportunity to call his driver down pit road for four Goodyear tires, fuel and wedge adjustments. Keselowski restarted the race in the 31st position on lap 17.
On lap 21, the No. 12 Penske Dodge Charger developed a vibration that got progressively worse the longer Keselowski remained on track. As Keselowski was about to make his way back down pit road for a green-flag stop, a lap 42 caution flag flew to allow him to bring the No. 12 in for service without losing a lap to the race leaders. Keselowski restarted the event in the 31st position on lap 47 and radioed that the vibration no longer existed.
As the race advanced past the first 100 laps, Keselowski dealt with a handling condition that moved from loose to tight. The Penske Dodge team made air pressure, track bar and wedge adjustments in hopes of giving Keselowski a car that he could race to the front of the field. However, the team could not find the right combination that would give Keselowski stability getting into the TMS corners, while keeping the car rotating in the center of the turns.
At the halfway point of the race on lap 167, Keselowski found himself running inside the top-20 for the first time during the event. The driver and crew chief developed a strategy for a two-tire stop that would give Keselowski valuable track position. However, the race did not unfold in a way that would allow Keselowski and Guy to capitalize on this strategy. The team kept giving its driver four fresh Goodyear radials on each pit stop, however, which gave Keselowski the best opportunity produce fast lap times. As the sun began to set behind the TMS grandstands and the track temperature began to cool, the handling of the No. 12 Penske Dodge became more to the driver's liking as he began to turn lap times as fast as the top-15 cars.
Following green-flag pit stops on lap 245, Keselowski returned to the track in the 21st position. While he was more comfortable with the handling of the car, Keselowski lost a lap to the race leaders on lap 268. After another green-flag stop on lap 286, the Penske Dodge developed another vibration with one of its tires. Not wanting to take any chances, Keselowski immediately came down pit road for a tire change to alleviate the problem. As a result, he fell another lap down to the race leaders. Although he continued to race hard throughout the final laps, Keselowski was not able to make up the lost ground and crossed the finish line in the 33rd position.
Following Sunday's result, Keselowski and the Penske Dodge Charger team remain 25th in both the driver and owner Cup Series point standings.
Penske Racing teammates Sam Hornish Jr. and Kurt Busch finished in 18th and 24th place, respectively, in the AAA Texas 500.
"We really struggled to get our car to run the whole corner," said Keselowski. "We had moments where we were good in the middle, moments where we were good in and moments when we were good off (the turns), but we couldn't find the answer for all four corners. We'll find out what we need to do to make our cars better. We're just missing a couple of little things. We just have to figure out what they are."
The No. 12 team will head to Phoenix International Raceway next weekend for the Kobalt Tools 500. The race will be seen live on Sunday, November 14 on ESPN, beginning at 3 p.m. EDT. The event will also be heard live on the Motor Racing Network, as well as Sirius Satellite Radio Channel 128.