By running your A/C you increase the fuel consumption due to the fact that the compressor (used to pump the gas) is hiched up to your engine via a belt!
So in theroy this will increase your 0-60 time too!
you can tell when you swich the climate control on an the engine tone dips! this is the compressor engaging!
So next time your out racing remember to swich off the A/C! lol