[818M3]

Can anyone who has real life experience chime in on this. I have been hearing the xdrive will start to act up with aftermarket wheels and tires. I am assuming it is very sensitive to weight distribution?

Thanks!

[Camarejh]

I had an F90 with aftermarket HRE 21s and it was fine. You have to stay within 1% in circumference difference otherwise it will act up. So just make sure you have the correct size tires on your aftermarket wheels and youll be fine. Theres a tire comparison website thatll give you all the details after you enter the tire sizes. Stay within 1% and youre good. Im sure someone else will chime in with the exact parameters but within 1% and youre golden. On my M5 i had 285/30 front and 295/30 rear and it was just fine.

[tooshay]

Gotta keep the tires diameter as close to stock as possible. Most say under 1% from front to rear.

[jummo]

I have had quite a few XDrive BMWs and run dedicated winter wheels and tires with no issue.
Some have been a different size than stock but as long as all four are the same, no problem.

[Jerrytarg6_m340]

Don't need to be a square setup Like others who said you just need to stay under 1%

[818M3]

What do you guys mean by 'within 1 %' of stock sizes? Do you mean the diameter, offsets and widths cannot have a difference (greater or less) of 1 %?

[TENPIN]

Originally Posted by 818M3

What do you guys mean by 'within 1 %' of stock sizes? Do you mean the diameter, offsets and widths cannot have a difference (greater or less) of 1 %?

Diameter.

With one tire significantly larger or smaller, the differential on that end of the vehicle will think the vehicle is turning (one wheel rotating faster or slower than the other) while the rest of the drivetrain thinks the vehicle is traveling straight with all wheels rotating at the same speed. This can put enormous mechanical stress on driveline components and lead to premature failure of expensive components.

[BulkBen]

Originally Posted by TENPIN

Diameter.

With one tire significantly larger or smaller, the differential on that end of the vehicle will think the vehicle is turning (one wheel rotating faster or slower than the other) while the rest of the drivetrain thinks the vehicle is traveling straight with all wheels rotating at the same speed. This can put enormous mechanical stress on driveline components and lead to premature failure of expensive components.

Correct, just to clarify through its diameter front and rear which must be closely matched (within 1%), this is quite different to the diameter needing to be 1% from stock as some others hand mistakingly suggested.

I’m confident that if were silly enough you could run 245/30 19’s square (which is 7% smaller diameter than stock) on this with matching rims, while not freaking anything out on the car.
You’d certainly trigger other drivers with how bad it looks though .

[Mowe]

I have not had any issues. I'm at 1.1% with a 285/295 20" setup.

[BulkBen]

Originally Posted by Mowe

I have not had any issues. I'm at 1.1% with a 285/295 20" setup.

This is helpful, we need a few more posts from people pushing the limits of what’s possible here, as 1% may be quite conservative.

Only guy so far who clearly had issues was running 285/35 19 on the front and 305/30 19 on the rear which is a whopping 2.5% off.

[818M3]

Originally Posted by Mowe

I have not had any issues. I'm at 1.1% with a 285/295 20" setup.

Do you have photos of your wheels on the car?

[Mowe]

Originally Posted by 818M3

Do you have photos of your wheels on the car?

Took a few today. No it the greatest but you get the idea.

[997CABOVA]

To stay within that 1.1% if you wanted a 20" setup around staying as close to OEM what would your ET and Tire setup look like??

Im a mess hahaha theres so many setups out here.

[Mowe]

Originally Posted by 997CABOVA

To stay within that 1.1% if you wanted a 20" setup around staying as close to OEM what would your ET and Tire setup look like??

Im a mess hahaha theres so many setups out here.

The offset will be the biggest dictator.

I have 285/30/20 and 295/30/20.

I don't believe anything bigger will up front with out severe rub. My offset up front is +6 and +12 out back. The front is a bit aggressive and I'd go a little less if I did it all over again.

[jeegunkim]

Originally Posted by Mowe

The offset will be the biggest dictator.

I have 285/30/20 and 295/30/20.

I don't believe anything bigger will up front with out severe rub. My offset up front is +6 and +12 out back. The front is a bit aggressive and I'd go a little less if I did it all over again.

EDIT:

DISREGARD -> So if you're at 1.1% with these sizes, what tire size would bring you back into the threshold of 1%?

NVM, just ran through this calculator and answered my own question above - 275/285 would get you to 0.8% but probably not the ideal size for the wheels I'm ordering.

Are you on xDrive? And even at 1.1% you haven't had any issues?

[Mowe]

Originally Posted by jeegunkim

EDIT:

DISREGARD -> So if you're at 1.1% with these sizes, what tire size would bring you back into the threshold of 1%?

NVM, just ran through this calculator and answered my own question above - 275/285 would get you to 0.8% but probably not the ideal size for the wheels I'm ordering.

Are you on xDrive? And even at 1.1% you haven't had any issues?

Have not noticed or had any issues. I think the .1 is negligible.