[MurphsLaww]

Howdy,

Long time BMW autocrosser, out of autocrossing for the last 5 years, and new to the 230i(2017).

My car has the 18" staggered tire package, and the SAT, and I'm looking at wheel and tire options. As one can imagine, what can fit, and if there are gearing considerations with the SAT in choosing 17", vs. 18" package?

RE-71R's are the likely choice.

Any opinions would be helpful.

Thanks all!

[TajoMan]

I used 235/45/17 with 17x7.5 ET40 RE71R last year.
It worked fine but side wall seems little too tall. (tread width was only 0.1" wider than 225)

I will use 225/45/17 this year. (or 225/40/18 if I can find cheap 18x7.5 rims).

If there was good tire in 245/35/18, I would run it with 18x8 ET40~43.
(No extreme performance tire in that size except Potenza S007)

[Maynard]

If you can fit 17's, that is a much better option for lighter weight and tire options, but I have to run 18s.

I'm running half inch wider staggered setup; 8" front, 8.5" rear et40 OZ Allegeritas with stock width 225/245 s007s. Lighter weight is noticeable, as is the taught sidewall. I really like the s007 as a step up from the Conti ExtremeContact - I didn't want to go to a 'dry summer' tire and needed them to work in wet and cold (mid 30s). These have about the same wet/cool traction, with basically the same tread style, and on track I get MUCH less edge wear (stock camber).

[MurphsLaww]

Anyone try a square 245/40-18 in front and a 255/40-18 rear ?

I had a 255 square setup on a prepared 93 M325is, which means nothing here, of course, other than others thought it wouldn't fit, and didn't even need the fenders rolled. I don't think I had camber plates on that car.

These would be on a set of race wheels so don't have to perform anywhere but on track. I might even run a trailer.

Haven't looked at the gearing yet, but the paddle shifter's are so smooth, I'm not sure I'm worried about shifting much.

My last experiences are in a 2015 mustang and just trying to get as much rubber down as you can.

[dradernh]

Originally Posted by MurphsLaww

Haven't looked at the gearing yet

The gearing changes only if you change the OEM tire diameter.

[MurphsLaww]

Originally Posted by dradernh

The gearing changes only if you change the OEM tire diameter.

Cool. Wasn't sure if there were considerations due to the 8 speed and 17 vs. 18. In the Mustang, I chose a base with the 3.31, and running 19's I think I was getting to around 70mph in 2nd, if I remember. Generally, it was only a consideration at regional sized courses.