I've currently ordered 225/255 RE71Rs but has some people here are no doubt aware the 255 isn't available. I'm allocated to Newark, Delaware where a shipment with enough tires to meet the demand at the warehouse (each warehouse is treated individually and each has lots of backorders) in late May. Scheduled, probable, but no certainty.

However, 245/40s are available. Right now actually. Would 225/245 be a reasonable setup?

Right off the bat I'm told the de facto taller gearing with the 255s helps in what are 2nd gear only courses. Not a street or track day issue, but this is for B Street autocross. If this was street only I would have done 215/245. If this was track day it would be a square setup on 17x9 wheels.

If I got the tires now I'd use them on Sunday...but maybe not again until June.

I'm not racing for a championship...so should I just wait?

 

if you arent in a rush, wait to get the the sizes you want.

 

I run 225 245 rs3s

 

And how do you like the setup? Do you run out of revs more quickly at autocrosses? What front bar setup are you using?

 

Ive ran 245/255 z1, 225/255 rs3 and zii, i went 225/245 this time around in hopes of having a tiny bit less sidewall wiggle in the back. I cant say i really notice a difference between a 255 and the 245. Maybe if i ran them back to back i could. I like tbe way ths 245 looks on the rim better
Stock suspension with comptech bar on full stiff

 

I have done and do a lot of fretting over a few millimeters of tire. But think about what the numbers mean. 245 to 255 is 10 mm. That width is split for each side of the tire. So to put it another way the 255 sticks out 5 more mm. Rounding up 5 mm is .2", so not even a 1/4". Yes the performance should be a tad better but your talking a 1/4" in relation to 10". Visually you will not even see it. So it is really up to. I do not think you are sacrificing anything seeing how you are not a national champion.

You actually may get better performance due to the stiffer side wall. For a 9" rim lots of people say 245 is the best size.

 

Like I said on the other thread, Alex ran the 225/245 combo at the Crows Landing Pro last weekend and was right with Brian in the BS C5 (also on Bridgestones) on scratch. And this was on a course that very much favored torque and the C5's 74mph 2nd gear. You can always move the 245's to the front when the 255's become available, if you feel the need. But, it appeared to work well.

 

Absolutely true...however the there is the issue of gearing. But again, it is so small it may not be noticeable. On the other hand, and although I'm no where near there (yet at least), the top two BS cars were separated by less than 0.2 sec, and a little further back where I do expect to run 3 cars were separated by less than 0.5 sec. In those cases every little bit counts. My wife thinks a good way to improve performance would be by weight reduction, around the drivers waist.

 

I ran for years on 275 Hoosiers and the change to a 255 was dramatic gearing wise. I ran out of gear several times last year when not expecting to. So much so I'm considering +1ing the rears for better gearing on bigger courses.

 

275 to 255 is something like 1/2" difference in rolling diameter. That's a bunch.