Quote Originally Posted by Newjack View Post
Alright I just did some math to figure out the cost difference between 18's and 17's. It's roughly $340 cheaper to go with the 17's 245's than it is to go with 18's 255's. I can get tires for a bit cheaper than tire rack by using my costco membership.

Should I wait for a group buy? I want to, but its not very smart. I need new tires on the front badly. Fronts have been on the car for over 4 years now and the tread is getting thin. Not to mention one of the front rims is bent and causing vibrations at highway speeds. To top it off one of the front tires is either really unbalanced, or has a permanent flat spot - Very loud "wub wub wub" noises at all speeds.

I've been looking at pictures of both 18's and 17's trying to figure out what I should go with. Derbo that last picture you posted sold me on the 17's. The price, the look, the comfort of hitting bumps and not crying myself to sleep - I dig it.



So my last questions are these,

Running 17x8.5 ET40 245/40/17 should fit my car just fine right? I am running an H&R Touring Cup Kit so my car is a little bit lower than stock.

Am I an idiot to try and run 255's on the 17's? Are the performance gains of 10mm on each tire negligible or is it just going to be too much of a headache to get the fitment right?

Is there a best place to buy the Apex rims from when not doing a group buy? Buying from Apex directly seems cheaper, but I don't think I've factored in shipping yet.


Thank you to everyone posting in this thread. I'm a lot older and make a lot more than I did when I bought the car 6 years ago, but spending 2 grand at one time is still a lot to think about. I tend to research stuff to death to make sure I make the right decision, and everyone's help here is greatly appreciated.
You already noted a large amount of problems that would be solved by replacing your rims. I say just do it! I bought them directly from Apex myself since they are about 1.5hrs away from me.


As your question, yes. It fits fine. No issues on my end. Like BMWCurves mention, they do look smaller in size in person. I personally got them for cheaper tires while not sacrificing too much. I used to go through tires every 6 months so the 17s" made sense to me.

255/40/17 is actually the proper tire size to match the stock ZHP tire diameter. I opt for 245/40/17 for rubbing issues. I was planning to go back to 255/40/17 but I needed tires for daily duty and PSS didn't make a 255/40/17. Next time around, I'll switch to 255/40/17.

In your situation, either tire size is fine. You will hear a little more road noise with a larger contact patch, tramline, minor extra weight, for the extra grip. IMO, 245/40/17 is still a great tire size (stock rear non-ZHP 330i.)


Another pic for attention.