what's the tallest tire diameter that will fit?

[JoeFromPA]

This question may be best for iND, who are doing great work showing fitment already.

I'm trying to determine what the tallest tire (total diameter) is that will fit within the stock F80 wheel well while allowing appropriate clearance.

I'm asking this for two reasons:

1. The best way to increase contact patch is to increase the total circumference of the tire.

2. I'm planning on staying with the 18" wheels and wouldn't mind putting some beefier tires on there when the time comes to fill in the gap, especially on the front.

This can be done by combining both sidewall aspect ratio increase AND/OR a wider tread with the same sidewall aspect ratio.

Input welcome

[IND-Distribution]

Modern BMW M cars have plastic wheel well liners that are progressively closer and closer in diameter to the OE BMW rolling diameter. From our experience fitting larger diameter tires poses the risk of rubbing, especially at the front of the car.

You can get away with approximately a 2% increase in the rear, but I strongly suggest using tires in front that are the OE outer diameter or smaller.

Keeping that in mind, we typically work to stay as close to the OE BMW outer diameter as possible to minimize any issues with ABS, speedometer readings, and so on.


In any case, there are other ways to generate additional mechanical grip- we are working on some solutions already and look forward to helping the M3/M4 perform even better than it did from BMW.

[jc05e46m3]

Originally Posted by Ilia@IND

Modern BMW M cars have plastic wheel well liners that are progressively closer and closer in diameter to the OE BMW rolling diameter. From our experience fitting larger diameter tires poses the risk of rubbing, especially at the front of the car.

You can get away with approximately a 2% increase in the rear, but I strongly suggest using tires in front that are the OE outer diameter or smaller.

Keeping that in mind, we typically work to stay as close to the OE BMW outer diameter as possible to minimize any issues with ABS, speedometer readings, and so on.


In any case, there are other ways to generate additional mechanical grip- we are working on some solutions already and look forward to helping the M3/M4 perform even better than it did from BMW.

This is completely true. Running 275/35/18 RS3s on Apex 10s Square dominated my front liner on the E92. Rear was fine.

[IND-Distribution]

Originally Posted by jc05e46m3

This is completely true. Running 275/35/18 RS3s on Apex 10s Square dominated my front liner on the E92. Rear was fine.

Agreed- anything taller than OE in the front of the E9x M3 cars would cut holes into the fender liners nearly immediately (and would then often move on to your washer fluid reservoir ). This is why we do everything possible to never install a front tire that is taller than the factory size.

[Taimur]

Interesting... I would like to hear more thoughts on this.

As I would probably consider running a taller stickier 18" tire or drag radial in the back once the car starts making 500+whp