[Tenac]

Hey All,

I did much searching on forum and google. I have never ordered Custom wheels before so I want to pick the brains of those who have and make sure I'm not crazy. Sorry for another wheel thread and thanks for the help. The searches have helped me narrow it down to this, really missing the offset and thoughts from those who have done this. 2022 M8 Comp Convertible.

I have found a few options that I am thinking about going too. For any option my tire will be the Michelin Pilot Sport 4s if available.

Ignoring brand of wheel for now, my goal is to get either forged with carbon fiber secondary or a full carbon wheels. Since I don't have the car to do actual measurements I don't fully know if my options will fit or what offset to request. The companies I am working with both offer to help here but I'd also like to hear others opinions on my options. I also do not want to use spacer and would like the rim to be set correct to have the tires out to the fender line. I'd also end up lowering most likely at some point (adjustable).


My goal is to go wider, and bring the tire to the edge without sticking out. I am also trying to avoid getting the speedo off to far by changing the overall rolling diameter.

First option: I think this is very subtle not sure if it will really make much of a difference.
F: 285/35/20 10x??
R: 295/35/20 11x??
I don't know what the offset would need to be since I cannot measure it?? Any input here, I know stock is 20.


Second option: Probably more inline with the width I'd like to see on the rear.
F: 295/35/20 10x?
R: 305/35/20 11x?


Third Option:
F: 295/35/20 10x?
R; 315/35/20 11.5x?



I am tossing up the idea to go to 21's with a side wall of 30. I know some have lowered with 21s but have you gone wider on the wheels? If so offset suggestions compared?


First option: 21's
F: 285/30/21 10x??
R: 295/30/21 11x??


Second option: 21's
F: 295/30/21 10x?
R: 305/30/21 11x?


Third Option: 21's
F: 295/30/21 10x?
R; 315/30/21 11.5x?

[Tenac]

No wheel experts out there to lend a hand to figure out the offsets? Or give me an honest opinion?

[zipstic]

The wider you go, the more your speedo is going to be off. You'll be traveling faster than what the speedo reads. But honestly it isn't going to be that much different and historically BMW has had their speedos read slower than your actual speed. Somewhere in the neighborhood of 2-3 MPH at 60 MPH.

The offset is going to be the complicated part. Until you can get your hands on the car and do some measuring it will be very difficult to know what offset is needed to get the wheel to sit flush with the fender.

[Tenac]

Originally Posted by zipstic

The wider you go, the more your speedo is going to be off. You'll be traveling faster than what the speedo reads. But honestly it isn't going to be that much different and historically BMW has had their speedos read slower than your actual speed. Somewhere in the neighborhood of 2-3 MPH at 60 MPH.

The offset is going to be the complicated part. Until you can get your hands on the car and do some measuring it will be very difficult to know what offset is needed to get the wheel to sit flush with the fender.

I didn't realize the wider tire would put the speedo off, Thanks!

Yeah that is why I was hoping maybe someone would see my options above and say this is what I went with or something like that. I think I have the rolling diameters locked in to be within .4% or so. Just need that dang offset to be sure.. lol

[Ehloo]

you can’t go wider without changing other specs of the tire. say if you got to a 315 you will need to go down to a 30 series. can’t keep the 35

i get wider tires but the m8 is all wheel drive. it has pretty good traction

are you going to lower the car? if so you are very limited on tire size


my BC forged wheels are 21x10 et 22 21x11 et 25. i am lowered and could of went with a couple more mm of offset. 275/30/21 295/30/21 Michelin PS4. wheels sit flush with the camber but got maybe 2mm i could of spared

Originally Posted by Tenac

I didn't realize the wider tire would put the speedo off, Thanks!

Yeah that is why I was hoping maybe someone would see my options above and say this is what I went with or something like that. I think I have the rolling diameters locked in to be within .4% or so. Just need that dang offset to be sure.. lol

[Tenac]

Originally Posted by Ehloo

you can’t go wider without changing other specs of the tire. say if you got to a 315 you will need to go down to a 30 series. can’t keep the 35

i get wider tires but the m8 is all wheel drive. it has pretty good traction

are you going to lower the car? if so you are very limited on tire size


my BC forged wheels are 21x10 et 22 21x11 et 25. i am lowered and could of went with a couple more mm of offset. 275/30/21 295/30/21 Michelin PS4. wheels sit flush with the camber but got maybe 2mm i could of spared

Thanks for the reply,

Yeah I plan to lower at some point, the kit would be adjustable so I should be able to tune in the settings to make it work as long as I don't go to wide.



Are you saying 295 in the rear is the max that would fit or could I go 305/30/21? And front I've seen 285 but not 295. I think 315 might be a pipe dream on the rears.

[qitbnoz]

I have a 2022 M8 GC and I'm pretty sure the sizes, offsets, etc are the same. Keep in mind that the second number in the tire size is the source ratio. In the stock tire 35 means the sidewall is height is 35% the width of the tire. As you go wider, the sidewall gets higher which may lead to ask kinds of problems with the all wheel drive system especially if you have significant front vs rear wheel discrepancies.

I went with 21x10 et18 with 285/30/21 tires on the front.
And 21x11 et25 with 295/30/21 tires rear Michelin pilots.

I think you could get to 305 rear tires with less aggressive offset but rubbing may be a problem going wider than 285 on the front.

My wheels sit pretty flush with the fenders front and rear. Ride height is stock. Tire diameter essentially unchanged compared with stock.

[LSM]

Originally Posted by qitbnoz

I have a 2022 M8 GC and I'm pretty sure the sizes, offsets, etc are the same. Keep in mind that the second number in the tire size is the source ratio. In the stock tire 35 means the sidewall is height is 35% the width of the tire. As you go wider, the sidewall gets higher which may lead to ask kinds of problems with the all wheel drive system especially if you have significant front vs rear wheel discrepancies.

I went with 21x10 et18 with 285/30/21 tires on the front.
And 21x11 et25 with 295/30/21 tires rear Michelin pilots.

I think you could get to 305 rear tires with less aggressive offset but rubbing may be a problem going wider than 285 on the front.

My wheels sit pretty flush with the fenders front and rear. Ride height is stock. Tire diameter essentially unchanged compared with stock.

Love your wheels

To add to OP question, if you start going outside the overall diameter of the stock setup as others have mentioned you will have issues with the awd system

Keep overall diameter bas close to stock as possible

[Tenac]

Originally Posted by LSM

Love your wheels

To add to OP question, if you start going outside the overall diameter of the stock setup as others have mentioned you will have issues with the awd system

Keep overall diameter bas close to stock as possible

Yeah totally understand, all my numbers above are between .4 - .7% of stock.

[Tenac]

Originally Posted by qitbnoz

I have a 2022 M8 GC and I'm pretty sure the sizes, offsets, etc are the same. Keep in mind that the second number in the tire size is the source ratio. In the stock tire 35 means the sidewall is height is 35% the width of the tire. As you go wider, the sidewall gets higher which may lead to ask kinds of problems with the all wheel drive system especially if you have significant front vs rear wheel discrepancies.

I went with 21x10 et18 with 285/30/21 tires on the front.
And 21x11 et25 with 295/30/21 tires rear Michelin pilots.

I think you could get to 305 rear tires with less aggressive offset but rubbing may be a problem going wider than 285 on the front.

My wheels sit pretty flush with the fenders front and rear. Ride height is stock. Tire diameter essentially unchanged compared with stock.

So your offset is 25 and 18??

I like the way your's looks for sure it does seem to come out a bit at the front from the fender if my eyes aren't lying to me.

[qitbnoz]

Originally Posted by Tenac

So your offset is 25 and 18??

I like the way your's looks for sure it does seem to come out a bit at the front from the fender if my eyes aren't lying to me.

Yes, those are my correct offsets. I know from the picture, the front tire appears to sit a little proud but the wheels are slightly turned to the left I didn't originally take the pictures to demonstrate the wheel offsets...just zoomed and cropped them. I think the fronts are perfect. My rears extend out ever so slightly.

[moonM8]

Originally Posted by Tenac

No wheel experts out there to lend a hand to figure out the offsets? Or give me an honest opinion?

Just saw this. I just posted my new wheels on my 2021 M8GC so that might help you. Here are the measurements and custom figments I used for my wheels. I went a little more aggressive than HRE suggested but I found them to be a lot more conservative nowadays. This worked perfect for me.

Take a look at my thread for photos. Hope this helps.


21" HRE Classic 300 FMR Wheels on M8 https://f92.bimmerpost.com/forums/sh....php?t=1861439

[Tenac]

Originally Posted by moonM8

Just saw this. I just posted my new wheels on my 2021 M8GC so that might help you. Here are the measurements and custom figments I used for my wheels. I went a little more aggressive than HRE suggested but I found them to be a lot more conservative nowadays. This worked perfect for me.

Take a look at my thread for photos. Hope this helps.


21" HRE Classic 300 FMR Wheels on M8 https://f92.bimmerpost.com/forums/sh....php?t=1861439

No issues with rubbing when full lock on the front? Are you lowered?

[moonM8]

Originally Posted by Tenac

No issues with rubbing when full lock on the front? Are you lowered?

No rubbing at all. Yes I'm lowered on KW Variant 4 coilovers.