[enVmyIX]

I just purchased a new to me 2012 F30 335i Sport with the 19" 401 wheels with Potenza R19 RFTs. I am going to change the wheels out to 18 " Apex EC-7 with either MPSS at 255/40/18 squared or another high performance, summer tire in 255/45/18.

My question is has or does anyone run a 45 series sidewall in 255/18? Will it fit without any trouble? How are the driving dynamics compared to a 40 series sidewall with 255/18? Thanks for your input.

[reedo302]

Edit: I was looking at 19" size. The 40 sidewall is sufficient. The 45 sidewall is going to give too much diameter to the tire.

You will also have trouble fitting a 255 up front. I run a 245 front and it's pretty tight to the point where a 255 would probably not fit.

Why do you want a thicker sidewall?
If you want a higher sidewall for driving comfort, go down to 17" wheels.

[.BMW.]

255/45-18 is too tall to fit up front. There is not enough clearance against the strut.

245/45-18 is the maximum front tire size, 255/45-18 fits in the the rear wheel wells though.

[.BMW.]

A few misleading comments in your post reedo302.

- 255/40-18 is indeed OEM size for F30
- There is nothing that says you cant fit tires that are more than 3% taller than OEM

[enVmyIX]

I want the max sidewall height for a 255 wide tire for an 18" wheel on all 4 corners for ride comfort/performance.

It sounds like 255/40/18 is probably the most suitable option.

[5hift]

Originally Posted by enVmyIX

I want the max sidewall height for a 255 wide tire for an 18" wheel on all 4 corners for ride comfort/performance.

It sounds like 255/40/18 is probably the most suitable option.

this thread might help you out


http://f30.bimmerpost.com/forums/sho...1244827&page=2

[T4NZ4NIT3 335i]

So much misinformation.

The max diameter tire you can fit upfront is either 245/45/18 or 225/55/17. Any larger and you hit the strut. You are oversize with these, which makes the rolling diameter large and reduces acceleration as it changes the final drive ratio.

If you are going square setup, go with 255/40/18 all round. Thats what I have on 18x8.5 35 offset wheels. No rubbing whatsoever, it can also take a mild drop. I plan to drop it with Bilstein B6 and ACS springs.

http://f30.bimmerpost.com/forums/sho....php?t=1275285

[reedo302]

I edited my last. Realized I was looking at 19" numbers.