I've ordered some new rims for my FC, and want to order tires. If I order the tires within the next 48-ish hours, I can get free mounting and balancing, so I'm hoping for some responses soon.

Wheels:
Front: 17x7 +38
Rear: 18x7.5 +38

What are the largest tires I can go with? In particular, I want the rear tires to be relatively large. How wide can I go?!?

 

Forgot to mention- S4 on stock suspension.

 

It's not easy to get wide tires on 7 & 7 1/2 rims. I would say 225 45 17 front and 235 40 18 rear is the widest I would go. If the rear rims were wider (say 8.5 or 9) I would do a 255/35/18.

 

I agree. Some of the mad tyte drifters on here will tell you its ok to stretch a 285 onto a 7'' wheel, but I would never do over about a 225 front and a 235 on the rear like derek said. Id say 225/40/17 front and 235/45/18 rear. I wouldnt do smaller sidewall in the back, itll look odd imo

 

I agree on the lower sidewall height on rear than the front lookng bad. Maybe the 225/40/17 front and 235/40/18 rear would be good. I think 235/45/18 would be too tall and make the speedo way off.

 

Well stock wheels are 16'', so going to 18'' with a 40 would still throw it off. So why not go ahead and put a bit thicker tire on the rear. Might throw it off another 1-2mph per 20 if that much

 

Thanks for the advice, guys!
I think I have what I need at this point. Unless anyone tells me absolutely not to, I will go with:
215/45/17 or 225/40/17 or 225/45/17 on the front
and
235/45/18 on the rear

I've done some calculations, and I'll need to do a measurement when I actually get my wheels with tires here, but I'm estimating ~10% difference in the speedometer reading per extra inch of diameter, assuming the outer diameter of the tires is between 20 and 25 inches.
So, that said, I can mentally compensate for the disparity in the speedo reading.

 

Oh, and I don't know a whole lot about cars, but I'm going to graduate with a degree in math in another year or two. If anyone else wants to know how much they're going to throw off their speedometer by changing wheel size, just ask.

 

Common tire sizes...
http://fc3spro.com/TECH/MODS/RT/tires.htm


-Ted

 

haha way to **** on his parade.

 

hahaha

actually I think RETed just added like 27.5 floats to my parade