[Raphael X4]

Originally Posted by FlyingAlpaca

Stupid tire questions follow:

Thinking about the M-sport diff on the X4 M40i. This selection demands a "low profile" 20" tire. BMW warns that these tires could be much rougher and risks vehicle damage.

Is a non-run flat "low profile" significantly rougher than a run flat?

Can I put non-low profile tires on later?

Are the OEM 20" non-run flats (Pirellis I think?) OK in the wet?

What about winter?

Ultimately I'm trying to make a call before I order, so any input will be appreciated.

Yes low profile is likely to cause more damage if hitting a pot hole.

Non-Run-flat results in a stiffer ride because the sidewalls of the tire are thicker so the tire can maintain shape if deflated.

Yes, you can put on non-run flat after.

In winter run-flat and non-run-flat doesn't really affect the performance. Things like tire make/model/type and size are more important.

[FlyingAlpaca]

Originally Posted by Raphael X4

Yes low profile is likely to cause more damage if hitting a pot hole.

Non-Run-flat results in a stiffer ride because the sidewalls of the tire are thicker so the tire can maintain shape if deflated.

Yes, you can put on non-run flat after.

In winter run-flat and non-run-flat doesn't really affect the performance. Things like tire make/model/type and size are more important.

Thank you Raphael X4!

[avi66]

Originally Posted by Raphael X4

Non-Run-flat results in a stiffer ride because the sidewalls of the tire are thicker so the tire can maintain shape if deflated.

I thought run-flat tyres were stiffer than non-run flat to maintain the ability to operate without air inside.

The run-flat side wall stiffness is why some claim the ride is harsher than non run flat.