[jnotrom711]

Am I the only one who doesn't love this look? Or get what the point is?

I feel like it would have been much better look and the car would look maybe a tad less bulbous if they put 21" all the way around?

Is there a specific reason for this ? I know the g90 isn't the only car they've done this on, g80 and M2 also is 19"/20".

I know it's not a major visual, it's subtle, but I can see it, definitely in the tires, and the front sidewalls look much larger than the rear to me.

[Remigijus]

They say that it's for performance, but doubt that any buyer would notice the difference.

I would also like front and back the same size.

[JtheW]

I don’t get it either and I’d prefer the same diameter all around.

[jnotrom711]

Originally Posted by Remigijus

They say that it's for performance, but doubt that any buyer would notice the difference.

I would also like front and back the same size.

Yes, this is kind of what i'm getting at also...

If there is a benefit to it that i'm not aware of thats entirely possible. But considering the F90 didn't have it that way, cant see it being that major.

I could see it more in RWD maybe? But honestly don't know. If anyone could cite what the benefit is and why that would be cool to understand the reasoning behind it other than it just being "cool", "edgy" or "stanced", IDK LOL.

[Remigijus]

BMW also states, that in this way you can have sharper turning with a slightly smaller wheel on the front.

G80/G82 thread https://g80.bimmerpost.com/forums/sh....php?t=1788420

Video (2:43)

[raym3cs]

in this video it is explained why the different size wheels front and rear
https://www.youtube.com/watch?v=NpcrEG79lkw

[jnotrom711]

Originally Posted by Remigijus

BMW also states, that in this way you can have sharper turning with a slightly smaller wheel on the front.

G80/G82 thread https://g80.bimmerpost.com/forums/sh....php?t=1788420

Video (2:43)

Thanks, makes sense, the turn in being sharper. Happy to know there is actually some real reasons for it.

Wonder why they couldn't accomplish that with just a different profile/width of tires. I know obviously the tires being different profile isnt quite the same as a smaller wheel all together. But as you mentioned being able to tell the difference would be tough for majority of people driving the cars.

I still would prefer all 4 corners being the same, LOL.

[Moewron]

Originally Posted by jnotrom711

But as you mentioned being able to tell the difference would be tough for majority of people driving the cars.

I think there's a LOT of stuff people are complaining about re: this car that fall into that category lol

[DocWeatherington]

Originally Posted by jnotrom711

Thanks, makes sense, the turn in being sharper. Happy to know there is actually some real reasons for it.

Wonder why they couldn't accomplish that with just a different profile/width of tires. I know obviously the tires being different profile isnt quite the same as a smaller wheel all together. But as you mentioned being able to tell the difference would be tough for majority of people driving the cars.

I still would prefer all 4 corners being the same, LOL.

You can always go square post ordering the car. However from a dynamic standpoint a staggered with a larger rear setup will normally always provide better vehicle dynamics.

However the suspension, awd, brakes and VSC are set up for this ratio. So going down to 20s around may come with negatives, but I'm betting bmw will have a square winter set.

The bulk majority of high performance cars/sports cars run a similar setup of smaller fronts and larger rears.

The m5 last gen had a staggered set but was 20 inch around.

[jnotrom711]

Originally Posted by DocWeatherington

You can always go square post ordering the car. However from a dynamic standpoint a staggered with a larger rear setup will normally always provide better vehicle dynamics.

However the suspension, awd, brakes and VSC are set up for this ratio. So going down to 20s around may come with negatives, but I'm betting bmw will have a square winter set.

The bulk majority of high performance cars/sports cars run a similar setup of smaller fronts and larger rears.

The m5 last gen had a staggered set but was 20 inch around.

Yes, my F90 I think 10-20mm narrower front, but the same size diameter. That is relatively normal I guess. But I would think with AWD a square set up is the norm. The width is narrower on G90 also. My F10 m5 I believe was also staggered, but that made more sense being RWD.

I cant imagine the overall diameter of the tire/wheel combo is much different since the front tires use a taller profile. 35R in the rear, and 40R in the front.

Don't fully know how to do the measurement I just know the 35 and 40 numbers are a percentage of the width.

I know a lot of performance cars have different widths front vs rear, but a lot of those are historically RWD, which makes sense..

I wouldn't go down to a 20" in the rear, I would have liked to see 21" all the way around.

[DocWeatherington]

Originally Posted by jnotrom711

Yes, my F90 I think 10-20mm narrower front, but the same size diameter. That is relatively normal I guess. But I would think with AWD a square set up is the norm. The width is narrower on G90 also. My F10 m5 I believe was also staggered, but that made more sense being RWD.

I cant imagine the overall diameter of the tire/wheel combo is much different since the front tires use a taller profile. 35R in the rear, and 40R in the front.

Don't fully know how to do the measurement I just know the 35 and 40 numbers are a percentage of the width.

I know a lot of performance cars have different widths front vs rear, but a lot of those are historically RWD, which makes sense..

I wouldn't go down to a 20" in the rear, I would have liked to see 21" all the way around.

You may be able to go 21s in the front but it may rub within the fender. Time will tell how much room there is but I know the rear 21 won't fit the front with the OEM rim size so you would have to go different rims all around. The rear tire width is massive for a sedan.

Square used to be but suspension dynamic and tire tech has improved so square in road performance on the upper crust of performance isnt isnt the way to go anymore.

Square for winter or off road has a purpose so use case.

Also to consider is the weight and the needed robustness of the tire and sidewalls.

I would check tire rack in a few months and see what they have. The tire sizes maybe pretty unique with few options.

[jnotrom711]

Originally Posted by DocWeatherington

You may be able to go 21s in the front but it may rub within the fender. Time will tell how much room there is but I know the rear 21 won't fit the front with the OEM rim size so you would have to go different rims all around. The rear tire width is massive for a sedan.

Square used to be but suspension dynamic and tire tech has improved so square in road performance on the upper crust of performance isnt isnt the way to go anymore.

Square for winter or off road has a purpose so use case.

Also to consider is the weight and the needed robustness of the tire and sidewalls.

I would check tire rack in a few months and see what they have. The tire sizes maybe pretty unique with few options.

Not 100% sure I'll even go with a g90, but possibly, will need to see and drive it to make that determination.

Im not worried about narrower tires in the front, so I supposed true "square'd" set up is not necessary. I mainly meant 21", widths could be altered, not worried about that. More the aesthetics of having front and rear wheels the same diameter.

A friend with a g80 did 20"s all the way around, and looks much better to me. widths not sure. but 20" front fills the gap much better vs 19 in the front.

I would likely go aftermarket anyway, since I dont love any of the 3 wheels BMW is providing.

I have the forged comp wheels on my f90C the 789m wheels, which I think are some of the best looking factory wheels ever. And the g90 wheels just dont do it for me yet. Maybe in person but, we'll see.

[M6-Coupe]

Originally Posted by Remigijus

BMW also states, that in this way you can have sharper turning with a slightly smaller wheel on the front.

G80/G82 thread https://g80.bimmerpost.com/forums/sh....php?t=1788420

Video (2:43)

Not sure if this is correct statement at all.
The front wheel size of G8x is 26.6" (275/35/19) and the rear wheel size is 26.7" (285/30/20) so just .1" bigger which is only 0.4%. That means the front tire at 7.5/32" tread is the same size of rear at 6/32" tread which is something not rare if you push the car more often especially with RWD competition.

[evanevery]

Originally Posted by DocWeatherington

You can always go square post ordering the car....

Not so... Its more than just the size of the WHEEL that needs to be considered.

If the effective circumference of the front vs rear TIRES is different (after considering the actual profile aspect ratio), then trying to square things up is NOT going to be a good idea...

[Cannondale900]

Originally Posted by evanevery

Not so... Its more than just the size of the WHEEL that needs to be considered.

If the effective circumference of the front vs rear TIRES is different (after considering the actual profile aspect ratio), then trying to square things up is NOT going to be a good idea...

Agree. The all wheel drive system is programmed to work with wheel/tire assemblies that have a specific rolling circumference at all four corners of the car. Any change to that rolling circumference will cause xDrive, DSC, etc to malfunction. If you increase the front wheel to 21" then you need to find a new tire width/profile combo that leaves you with nearly the same rolling circumference as the factory 20" wheel/tire combo.

I agree the look is noticeable but it doesn't bother me that much and I like the idea of more tire sidewall than less.....allows you to hit pavement irregularities and objects in the road without significant risk of damage to tire or wheel. Also sidewall gives a bit of damping before transmitting vibrations etc to suspension and chassis.

I have a 2022 RS6 with the 22" wheels and although they look good, the tire sidewall is a 30 profile.....it's like driving on rubber bands. I spend a lot of time being careful about where I place the car in the roadway instead of just enjoying the drive. Probably going to put it up for sale in the coming weeks or so as I've spec'd a G99.

[DocWeatherington]

Originally Posted by evanevery

Not so... Its more than just the size of the WHEEL that needs to be considered.

If the effective circumference of the front vs rear TIRES is different (after considering the actual profile aspect ratio), then trying to square things up is NOT going to be a good idea...

I agree fully... there is alot of things that go into switch tire/rim sizes on high performance cars with advanced systems.

I mention that in another post above. Normally bmw offers some winter package for m cars and those historically have been square and smaller rim/tire combos.

[Crazy1323]

Originally Posted by DocWeatherington

I agree fully... there is alot of things that go into switch tire/rim sizes on high performance cars with advanced systems.

I mention that in another post above. Normally bmw offers some winter package for m cars and those historically have been square and smaller rim/tire combos.

The factory tires are 285/40/20 front and 295/35/21 rear. According to Michelin’s website the revs per mile of these tires are 718 and 715 respectively, that means that the from the factory the front wheels spin 0.4% faster than the rears. If the rear tire were used on the fronts then front and rear would both be 715 revs per mile. That is not a big enough difference for anything to care.

The rear wheels are are 21x11 with a 28mm offset. The fronts are 20x10.5 with the same 28mm offset. Since both wheels have the same offset, running the rear wheels on the front would just mean going 1/4” further out on each side.

So, a square stance on 21’s should not be a problem. Aftermarket is easy, but you can probably do it just by using OEM rear wheels and tires on the front.

However, if you want to go to with aftermarket 22’s that may cause issues. This baby is heavy! Finding a 22” tire with the appropriate load rating could be hard. I think the factory tires have a load rating do 111 front and 110 rear.

[DocWeatherington]

Originally Posted by Crazy1323

The factory tires are 285/40/20 front and 295/35/21 rear. According to Michelin’s website the revs per mile of these tires are 718 and 715 respectively, that means that the from the factory the front wheels spin 0.4% faster than the rears. If the rear tire were used on the fronts then front and rear would both be 715 revs per mile. That is not a big enough difference for anything to care.

The rear wheels are are 21x11 with a 28mm offset. The fronts are 20x10.5 with the same 28mm offset. Since both wheels have the same offset, running the rear wheels on the front would just mean going 1/4” further out on each side.

So, a square stance on 21’s should not be a problem. Aftermarket is easy, but you can probably do it just by using OEM rear wheels and tires on the front.

However, if you want to go to with aftermarket 22’s that may cause issues. This baby is heavy! Finding a 22” tire with the appropriate load rating could be hard. I think the factory tires have a load rating do 111 front and 110 rear.

Yeah, I'm not expecting alot of options tire wise in general due to the weight/size.

I'm hoping we will be able to find winter or even an all season option for the oem rims, for those in winter climates.

If not your going to have go with a second set of rims.

[Cannondale900]

Originally Posted by Crazy1323

The factory tires are 285/40/20 front and 295/35/21 rear. According to Michelin’s website the revs per mile of these tires are 718 and 715 respectively, that means that the from the factory the front wheels spin 0.4% faster than the rears. If the rear tire were used on the fronts then front and rear would both be 715 revs per mile. That is not a big enough difference for anything to care.

I've learned to not be so dismissive of this relatively minor difference. I have a 2010 535ixT and futzed with different wheel/tire combos that created differences in rolling circumferences front/back of roughly the same percentages as above. The result.....dashboard Christmas tree.

Without knowing how the engineers have programmed the systems in the G90/G99 to account for these differentials it is impossible to say what the results might be.

Someone will do the experimenting and find out. I'm unlikely to be that person.

[mjr24]

The X5M also runs different sizes front/rear (fronts are 21 inch and rears are 22 inch). Made it a PIA to find any selection of tires for the most part.....especially winter/all season (in which there was 1 winter set total that fits the X5M/X6M and they are sold out normally months in advance).

I know the i5 M60 tire sizes for their optional 21 inch wheels have absolutely no winter or all season tire options, either. The main issue is the load rating due to the car being so heavy. In other words, there are tire sizes that fit....but none of them have the required load ratings the M60 needs. Might be a deal breaker for some in colder regions if no one offers any all-season or winter tires for this car.

[pmsteinm]

The difference is the front wheels end up with more sidewall. I know they said it helps steering but I would think more sidewall would make the steering less precise. But with more sidewall they can tune the suspension differently and still get the compliance over bumps. Maybe that then lets them get a better steering setup since the tire can absorb more impact.