[MADBMWX5MC]

Has anyone tried taller tires on the Rear 22 x 11.5 rims that comes with OEM 315/30/22 tires?

I have no issues with the front tires that are 295/35/21, but the 315/30/22 on the rear are really skinny....

[eelnoraa]

Assuming outer diameters are supposed to match. Fronts use 21", rears use 22', meaning rear side needs to be 0.5" smaller. The only way to increase side wall without impacting OD is to reduce wheel size. So rear wheels needs to be reduced to 21".

If I use tire size calucator, I got these

295/35R21, OD = 29.1"
315/30R22, OD = 29.4"

Rear is + 1%. We have to assume 1% is within BMW design tolerance. To be within 1% of the front, here are some examples

295/35R21: exact same as front. square setup
305/35R21: +1%. same difference as what you currently have
335/30R21: -0.7%,
345/30R21: 0%
355/30R21: +1%

You will need to get new 21" rear wheel anyway. 295 and 305 should fit. 335 and beyond, it really come down to clearance and offset.

[MADBMWX5MC]

That's some great information. I agree with you on getting 21's. Never been a fan on 22', specially with the roads around me here in Northern VA. Thank you!

[Black5spdz]

We did 295/40/21 and 315/35/22 on my wife’s car for ride quality, rim protection and to get an all season Continental dws on it. With those tires and lowered on mss the ride is better than stock, tires don’t pick up every rock and can be left on for us all year. To me it looks better than the stock size rear tire that appears stretched and very little sidewall.

[MADBMWX5MC]

Originally Posted by Black5spdz

We did 295/40/21 and 315/35/22 on my wife’s car for ride quality, rim protection and to get an all season Continental dws on it. With those tires and lowered on mss the ride is better than stock, tires don’t pick up every rock and can be left on for us all year. To me it looks better than the stock size rear tire that appears stretched and very little sidewall.

Exactly why I asked. Pic helps understand the concept. Thanks for adding it. BTW, did you have to adjust anything to let the X5 know you had a different tire than stock? I recall in my X3 I had to adjust measurements thru the iDrive when I went from 19" stock to 20"

[Chong]

Originally Posted by Black5spdz

We did 295/40/21 and 315/35/22 on my wife’s car for ride quality, rim protection and to get an all season Continental dws on it. With those tires and lowered on mss the ride is better than stock, tires don’t pick up every rock and can be left on for us all year. To me it looks better than the stock size rear tire that appears stretched and very little sidewall.

Hey, I was just wondering how low you are on the MSS Springs and if you have any rubbing issues? I'm lowered on MSS currently and was wondering if I'd run into any issues.

[SlowX6M]

Originally Posted by Black5spdz

We did 295/40/21 and 315/35/22 on my wife’s car for ride quality, rim protection and to get an all season Continental dws on it. With those tires and lowered on mss the ride is better than stock, tires don’t pick up every rock and can be left on for us all year. To me it looks better than the stock size rear tire that appears stretched and very little sidewall.

This actually looks great!

[marillo]

Why does tire width affect the % difference ? it should just be diameter which would just be side wall and rim size ? what am I missing ?
For example 275/40 r20 is -1.4% yet a 285/40 r20 is -0.3%
I guess it is a percentage of the width not an absolute measurement.

My ultimate question is do you think a 275/45 r20 would be ok for the 2024 x5 m comp ? for winter of course

[eelnoraa]

Originally Posted by marillo

Why does tire width affect the % difference ? it should just be diameter which would just be side wall and rim size ? what am I missing ?
For example 275/40 r20 is -1.4% yet a 285/40 r20 is -0.3%

Because the height of side wall is defined by aspect ratio number, the 40 here. It means side wall height is 40% of the width. So same aspects ratio, wider tire, taller side wall, larger overall diameter.

[marillo]

Sorry I edited it - see last part

[svangron]

I've been looking at this also. The front looks fine in the 295/35/21, but the rear tire I would like a bit more sidewall. Looking at moving up to a 325/35/22 which would add 1.6" to the overall diameter. Michelin offers their Pilot Sport 4S in this tire.

[eelnoraa]

Originally Posted by svangron

I've been looking at this also. The front looks fine in the 295/35/21, but the rear tire I would like a bit more sidewall. Looking at moving up to a 325/35/22 which would add 1.6" to the overall diameter. Michelin offers their Pilot Sport 4S in this tire.

Wow, front vs rear will be 1.9” or 6.5% different. No man, it is a significant.

[MADBMWX5MC]

Well, closing the loop since I started this opne...as I am concern, I am staying with OEM dimensions for now.

[svangron]

Originally Posted by eelnoraa

Wow, front vs rear will be 1.9” or 6.5% different. No man, it is a significant.

The comments above are based on arbitrary "assumed" tolerances that BMW has. The overall diameter of the tire IMO shouldn't make that big of a difference other than it may throw the speedo off a small amount.

I was just asking if anyone else has tried other tires sizes.

[fl_x5m]

Originally Posted by svangron

The comments above are based on arbitrary "assumed" tolerances that BMW has. The overall diameter of the tire IMO shouldn't make that big of a difference other than it may throw the speedo off a small amount.

I was just asking if anyone else has tried other tires sizes.

It wouldn't work in that size. Your rear tires would be doing 652 revs per mile and fronts 693 revs per mile. Original tires are only 7-8 revs per mile difference. You're looking into mechanical problems if you run this set up.

[eelnoraa]

Originally Posted by svangron

The comments above are based on arbitrary "assumed" tolerances that BMW has. The overall diameter of the tire IMO shouldn't make that big of a difference other than it may throw the speedo off a small amount.

I was just asking if anyone else has tried other tires sizes.

This comment is from someone has no idea how xdrive works or how many have had transfer case issue. Please search in YouTube.

[Jeff J]

eelnoraa Not trying to hijack, but could you explain or point to a particular link regarding why a larger diameter tire would cause an issue with the transfer case? I'm assuming same diameter front/rear - I completely understand why different diameters front/rear would be an issue. I don't understand why changing the rolling diameter equally F/R would cause issues with anything beyond speedometer accuracy (and fender rubbing if you took it too far).

Edit: I see now that you're referring to the above commented 6.5% difference front/rear. Yeah, that would be a problem for the transfer case.

[eelnoraa]

Originally Posted by Jeff J

eelnoraa Not trying to hijack, but could you explain or point to a particular link regarding why a larger diameter tire would cause an issue with the transfer case? I'm assuming same diameter front/rear - I completely understand why different diameters front/rear would be an issue. I don't understand why changing the rolling diameter equally F/R would cause issues with anything beyond speedometer accuracy (and fender rubbing if you took it too far).

Edit: I see now that you're referring to the above commented 6.5% difference front/rear. Yeah, that would be a problem for the transfer case.

Yes. Larger diameter in all corners, but consistent diameters, the xdrive doesn’t know. This impact two things: Speedo and potential physical clearance.

Now different diameters front and rear, I think if difference is small, it should be ok. I refer to x5m 21/22 setup, there is a 1% difference from BMW factory, is is the largest front/rear difference I can find within x5 factory setup. I think we can safely assume 1% is ok. While I don’t know for sure at what % problem will arise, we were taking 6.5%, not 1.5%, I won’t take this risk myself.

Calling 6.5% is manufacturer tolerance is laughable. In the world of mass manufacturing, 6.5% off target is called defect. This part will be rejected. As simple as windshield wiper cannot be 6.5% off target from manufacture. Heck, even if you go to home depot buy a piece of lumber, they cannot be 6.5% off target.