[m440i804]

Modern Spare uses 135/70 R18 as the spare tire in the kit they have for the m440i. I put the sizes into the comparer and wanted to know if the overall circumference of the tire would cause an issue with the xdrive system? If so, should I change the doughnut out with a 145/70 R18?

Thanks for any help provided.

[prostcfc]

The circumference difference is > 1%, so theoretically, yes, it would be a problem for xDrive. Then again, a spare is supposed to get you to a tire repair spot, not driven indefinitely, so I doubt there will be any damage. 145/70-18 is within the 1% margin.

[m440i804]

Originally Posted by prostcfc

The circumference difference is > 1%, so theoretically, yes, it would be a problem for xDrive. Then again, a spare is supposed to get you to a tire repair spot, not driven indefinitely, so I doubt there will be any damage. 145/70-18 is within the 1% margin.

Would you change out to a 145/70-18, or let it be?

Thanks for your input.

[prostcfc]

Originally Posted by m440i804

Would you change out to a 145/70-18, or let it be?

Thanks for your input.

I would change it, yes.