Tire options for square setup

[munroe7]

Hey guys I have a set of D-Force empower wheels that im going to put on my ZHP. I know that the ZHP rears stock are 255 and the fronts are 225 (I think). The D-Force wheels are 8.5 inch wide (square setup) and they have 225's on now and it gives them a nice stretch but nothing crazy. My question is will these small tires affect my handling? Should I go with larger tires all around on my new wheels?

[Vas]

A good width size would be a 235 or a 245 section width. 225 on all for corners are a bit undersized IMO

[UdubBadger]

I run 225s on our E91 in 225 on 8.5" rims. It's not badly stretched but since they're all seasons and we get some good snow here in winter I opted to stay a bit thinner than where I could have gone. 235 might be preferred for next time but this works.

That being said I run 265 square on 9" rims for my M lol


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[az3579]

I have 245/35-18's all around on 8.5" wide wheels. They look absolutely perfect and can attest to the performance being spot on as well.

[BMWCurves]

I have 245/35-18's all around on 8.5" wide wheels. They look absolutely perfect and can attest to the performance being spot on as well.

That was my plan when I move to a square ARC-8 setup, or 235 section width. Looking at a tire size calculator (http://tire-size-conversion.com/tire-size-calculator/) (taken with a grain of salt since tires vary by brand and line) the rough differences in diameter are as follows:

Rears:
- 245/35-18 tire is about -0.8% for the rear as compared to the stock 255/35-18.
- 235/40-18 tire is about +1.6% for the rear as compared to the stock 255/35-18
- 235/35-18 tire is about -2.0% for the rear as compared to the stock 255/35-18

Fronts:
- 245/35-18 tire is about -1.2% for the front as compared to the stock 225/40-18.
- 235/40-18 tire is about +1.2% for the front as compared to the stock 225/40-18.
- 245/35-18 tire is about -2.4% for the front as compared to the stock 225/40-18.

From that I think I like your 245/35-18 square option. Least change in the rear tire so the speedometer measurement will remain close to stock, the difference in the front isn't bad, and I'd prefer to minimize the reduction in rear tire width.

[Vas]

You can always reprogram the speedometer so it shows the correct speed :P

[UdubBadger]

Mi says go 235/40


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[az3579]

Mi says go 235/40


GoingHAM mobile

Taller profile = slower.

From that I think I like your 245/35-18 square option. Least change in the rear tire so the speedometer measurement will remain close to stock, the difference in the front isn't bad, and I'd prefer to minimize the reduction in rear tire width.

One problem I ran into with 245/35-18 is the tire choices seem to be more limited. I can't find any higher performance alternatives in that size, they all only offer 245/40-18 as the closest option, which is a big difference. The overall wheel/tire size is larger that way and frankly doesn't look as good. I would have run into fitment issues with 245/40. I'm running it pretty close on 245/35 as it is... but then again, my car is quite lowered.

[BMWCurves]

You can always reprogram the speedometer so it shows the correct speed :P

Very true, but less hassle in some ways.

Mi says go 235/40

Mi?

One problem I ran into with 245/35-18 is the tire choices seem to be more limited. I can't find any higher performance alternatives in that size, they all only offer 245/40-18 as the closest option, which is a big difference. The overall wheel/tire size is larger that way and frankly doesn't look as good. I would have run into fitment issues with 245/40. I'm running it pretty close on 245/35 as it is... but then again, my car is quite lowered.

That is one thing I noticed when doing a cursory look at availability of different tire sizes. What are you running right now?

[UdubBadger]

Mi = me in español