Greg, you really want to run the smallest slick that is consistent. On my old Mercury Cougar we had something like 13x32's originally. Couldn't get the car on my trailer with those tires, so had an old pair of 9x28's that we used just for transport. One day at the track it looked like rain so we didn't put on the big tires (didn't feel like changing tires in the rain). The car ran the best ET and MPH ever. Never put the big tires on the car again. PS: The cougar would 60 ft 1.58, 10.80's, 122 mph with the smaller tires.

From a post on FABO


Also when I ran 3/8 mile circle track, I was DQ one night for tires being too big (had to run street tire no larger then a certain size.) I put on a smaller tire (same dia, smaller width) and my lap times got quicker.
Comes down to rolling resistance, and rotating mass.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 225 nitrous
64 Valiant Signet
64 Valiant 4dr 170

I did that at Clay City when I debuted the car. Did you know the needle on an Autometer mechanical gauge will go way past 260 and not break? Yeah, me neither.

I always leave mine on. I has the dumbs sometimes.

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Official Cookie and Mater Tormentor.