Hello everyone, I need your opinions. I have purchased OEM 437m wheels for my F32 sport package. The thing is, my car has 18” wheels and the 437m’s are 19’s. I’ve seen a few threads about putting the 437m wheels on F32’s but they already had 19” wheels on their car. My car is an xDrive which may make things more difficult. My current tire setup is 225/45/18 on both front and back wheels. If I was to get lower profile tires, would everything function correctly?
Last edited by TheArctic; 08-26-2021 at 09:00 PM.
You can run 18s, 19s or 20s - they just need to be the right sizes (doesn’t matter what your original diameter was).
The problem with the 437Ms on the F30 chassis is the wheel width and offsets. The front is 19x9 et 29 and the rear is 19x10 et 40. It will be difficult to not have them poke or rub, and the fact you have Xdrive makes fewer tire selections possible.
The key for Xdrive is the diameter of the tires needs to be within ~1%, so to not have transfer case issues.
The 437s typ come staggered with 255/35 fronts and 275/35 rears - but you can’t run that on X-Drive because the diameter difference exceeds the 1%.
So you’ll want to try to run either a square set-up, with same tire size front & rear (maybe a 255/35 all around even though it might poke in the front and be stretched more on the rears) - or a staggered combo like 235/35 front and 265/30 rear (where the tire diameters are within 1%).
So just out of curiosity, do you have a website or an app you use to calculate the % difference? If so, how do I calculate it? Sorry I’m pretty new to putting any different kind of wheel besides the stock one on my car. Also, if the tire size is different than the original, won’t it throw off the wheel speed sensors?
Look at the specs for the tires you’re buying. They list the exact diameters there.
The F30 is designed to fit a tire of approx 26.0” diameter (this is what your speedo expects).
A 225/45-18 and a 255/40-18 (OEM 18” staggered sizes) are this size, as are 225/40-19 & a 255/35-19 (OEM 19” staggered sizes). If done properly, the tire diameter doesn’t change as the wheel is larger; note the aspect ratio of the tire goes down to ‘match’… So generally 45 series for 18” (40 if wide) and 35 series (30 if wide) for 19s.
As I mentioned earlier given the diameters/offsets of the 437M wheels, and the fact you’re Xdrive it’s hard to do. The 235/35-19 & 265/30-19 combo I cited earlier, or a 245/35/19 & 275/30/19 combo are right at the limit for diameters within ~1%.
Last edited by visionaut; 08-27-2021 at 06:33 PM.
I’m a bit lost. I punched the numbers you gave to me into a tire size calculator and it came back as greater than 1%, unless I’m misunderstanding something which is totally possible
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EDIT: I’ve actually looked at a few other forum threads and found most people use the 235/40 and the 265/35 combo. Do you think that would work for my setup? Also I think I’m now beginning to better understand this whole thing
EDIT2: Okay I’ve fully understood this whole thing now. For some reason when you said 1% I thought you meant the tires needed to be within 1% of the tires already on the car, but I now realize you mean the front and rear tires need to be within 1% of each other. So now my question is, do I go with the 235/40 and 265/35, or the 235/35 and 265/30? I have heard there is a slight amount of rub with the former, however I live on the east coast which is prone to potholes and this car is my daily. Plus I feel like the latter would be better for handling and performance as well.
Last edited by TheArctic; 08-27-2021 at 09:20 PM.
Sure, the 40 & 35 version also fits the 1%, and you could use the extra sidewall, so go for it.
That combo is 10mm wider front and rear & the same aspect ratio vs. the OEM 19” staggered set (225/255). The 437s wheels are 1” and 1.5” wider than those OEM 19” staggered wheels.
There will be minor stretch with those tire widths, and the front rim will poke regardless of tire - but they’ll work. Since they’re taller than 26”, your speedo will be off accordingly, and the height contributes to the rubbing.
But would 275/30/19 be very aggressive for the rear, I just purr some 437m wheels and I’m just trying to find the correct tire setup or atleast a setup that won’t effect the xdrive
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