ACR-Mark

I have an 09 that I am running in BS trim, in an indexed Street Tire class in our local region. My current setup is 245/40-18 on 18x8.
The 2009 8's have a lower final drive, so top speed in each gear is lower than on the 04-08 models, but technically, I guess it is possible to accelerate faster in those gears? Maybe, maybe not.
Anyway, I had a thought that it might be beneficial to try a 245/45-18, in order to gain some of that gearing back. Yes, technically it would accelerate slower, but that never really seems to be a problem with my car, while running out of speed in 2nd gear does happen. I figure worse case scenario, the acceleration may even out with an 04-08, or maybe a bit slower.
Any thoughts and input on this? There are 3 pretty good street tire options in that size: Star Specs, AD08's, RE-11's.

Zoom4Three

I would opt for the acceleration advantage and slightly lower CG of the shorter tire (.5" radius change in this case). These benefits will help on a lot higher percentage of the course than the 2 mph increase in top end speed.

Chris H

ULLLOSE

iTrader: (1)

I also doubt the shorter gearing will be as much of an issue for you on street tires VS the guys on R compounds. Your corner exit speed and top speed will be lower, so you are less likely to run out of gear.

I thought I read one report from an 09' BS driver that the 18" cars on short Rs are not even able to hit 60mph in 2nd.

treinhar

GPS speeds top out at 59+ to maybe 60 on 285's in my 09.