[Streetdaddy]

Wondering if anyone has made this comparison?

[Phasers]

Originally Posted by Streetdaddy

Wondering if anyone has made this comparison?

What 22" non-run-flat is available for the rears in factory size?

[MystroX5]

21" will regardless. There is a vibration and acoustic component the 21" ers don't deal with nearly as much as the 315 22" er.

[Streetdaddy]

Actually i was trying to find out about a square 285/40/22 setup on factory vs square 21”. Another option is getting 4 of the 9.5” wheels all around.

[BimmerBud]

Will BMW allow a square 22” with all four wheels in the 9.5” configuration? That would be ideal to enable rotation, otherwise can still go square 285/40/22 but would not be able to rotate front and backs

[Streetdaddy]

What width are the factory 21”??

[Streetdaddy]

Would the 285 be quieter than the 315? In the 10.5” rear wheels?

[keg97]

Originally Posted by Streetdaddy

Would the 285 be quieter than the 315? In the 10.5” rear wheels?

I'm throwing this out there and could be completely wrong....but I'd think the tire design itself is the bigger variable, rather than a less than 10% difference in size. Tires are designed for different characteristics (handling/weather/longevity/etc) so some tires are just naturally noisier than others.

But all things being equal, yes the 285s will be slightly quieter than the 315s.

[streborx]

Many factors contribute to noise and ride comfort, including the road surfaces you normally drive on and the tread design. If you drive on roads whose maintenance is filling cracks with hot asphalt, filling potholes, and eventually chip sealing, every tire will deliver a harsh experience. Knobby aggressive treads tend to be noisy, and even more so on lousy road surfaces, and as the knobby tread wears.

I had my 22" OE run flats (Conti's) on my X7 for about 1K miles, and on good roads, I had no complaints. I never tried them on bad road surfaces. I switched them out to 20" squared-up A/S's nft's, and find these new tires as good as it gonna get everywhere I've driven.

[chicagox7]

Originally Posted by Streetdaddy

Actually i was trying to find out about a square 285/40/22 setup on factory vs square 21”. Another option is getting 4 of the 9.5” wheels all around.

It may be worth searching the forum on tire sizes and ‘square set up’. I’ve seen a number of threads since I joined in Dec ‘23 and found many more when I did some research (landed on 21’s because of the research). A few folks have gone into great detail about the sizes that could work for a square set up and not cause issues- including sharing calculations and formulas, others have talked about how BMW reacts/views this in terms of the warranty and there are a number on the comfort/ride factors.

Most agree that a good 21 will offer better ride and less noise than 22’s. There are members who actually have both 22’s for daily driving and then switch to 21’s for long road trips. Also, non-run flats will generally be smoother than run flats.

While not a direct answer, hopefully some of the past threads help you out with this!

[jabbarjd]

Originally Posted by Phasers

What 22" non-run-flat is available for the rears in factory size?

Pirelli P Zero PZ4

[Phasers]

Originally Posted by jabbarjd

Pirelli P Zero PZ4

Touche

[Orient330iNYC]

Originally Posted by BimmerBud

Will BMW allow a square 22” with all four wheels in the 9.5” configuration? That would be ideal to enable rotation, otherwise can still go square 285/40/22 but would not be able to rotate front and backs

define allow?
sell from the factory? no
will it fit? yes
you would need to pick up 2x more front rims.