I have a 05 4.4 and went to the Infineon Raceway quarter mile drag strip. I got to run two times, the first time I got was 15.486 and the second time I got was 15.542. The temprature was 80 degrees. I also thought that my X5 was slow to act, right when the green signals me to go I stomp on the gas but it hesitate for a second then it goes..

It shouldn't matter at the raceway because the time doesn't start counting before the car moves...