rbarna

I'm looking at some 18x8.5" wheel options and wondering what tire size I would need. My suspension setup is stock sport springs on neuspeed bilsteins.

Thanks!

-r

Kapoosh1

i run 18x8.5 and have 225/40

Turning Japanese

225/40, 235/40, or 235/35

Digit@lex

225/40/18 looked too thin for my 8.5" wide rims. I had my front fenders rolled for extra precautions against possible rubbing. No issues so far.

Skene @ PES Tuning

i would say 235/35

rbarna

Why not 235/40?

rbarna

could you please explain the tradeoffs involved?

Turning Japanese

235/40 vs 235/35: The extra sidewall on the 40 will help to absorb impact and decrease the chances of bending a rim. However, the larger over diameter of the wheel also increases the chances of rubbing. The lower profile 35 also looks better. Handling will be better with the 35s because there will be less sidewall flex. With 40s, your speedo will be slow, and with 35s, it will be fast.

With the 225/40, you will have the least chance of rubbing and your speedo will be the most accurate. However, you will have less of a contact patch (less traction). Also, a 225 may look to small for the 8.5" rim.

Skene @ PES Tuning

running a 235 tire diameter and 40% height on an already 8.5" wheel, your speedometer would be out of wack from the tire size and diameter differences from stock. To keep it closer to stock form a 235 diameter and 35% height would be sufficient enough.. if you would like to try the 40% height.. welcome to the world of slow non agressive driving. (rub)

Digit@lex

That's bullsh!t on everyday driving. If you'll be performance driving...go for 17s then. Seems to he's going for looks. The difference between 235/35/18 and 235/40/18 is negligible in all but the the most aggressive driving...and I'm talking pushing the limits driving on a track.