[MotoMoto]

Hey guys 'n gals,

I thought I understood most car things to a decent level, but then tyres...

I just read the sticky from the sponsors, but can you guys confirm I'm understanding it right.

Just took ownership of a 2015 330d F31 xDrive M Sport - Hurrah! - and have been doing some research and reading on the foibles of the Drive system. Checking my tyre sizes to see what the PSI should be, I spotted I had what I thought was 2 different sizes on the car.

Front 225/40R19
Rear 255/35R19

Up until about 20 mins ago, I always thought the 2nd figure was a mm measurement of the sidewall. But have I read correctly, that it's a ratio of the width to height? So essentially, these are the same profile tyres, and I don't need to worry about my xDrive transfer box exploding

As an aside, I thought from my reading that the xDrives didn't come with staggard wheels.

[alohasurftoad]

Bmw offers staggered wheels/tires on all of their series and models with x-drive.

225/40/19-255/35/19 is OEM size combo on F3/4 series including x-drive.

[MotoMoto]

Is that right? I clearly need to do a little more homework.

Thanks for the heads up Surftoad.

[thejeremyman9]

I suggest you start with a google search on how to read tire specs and go from there.

https://www.goodyearautoservice.com/...ll%20will%20be.

[MotoMoto]

Originally Posted by thejeremyman9

I suggest you start with a google search on how to read tire specs and go from there.
.

I didn't know I needed to, until yesterday I had honestly gone 46 years thinking the second number was a height measurement.

Thanks for the link, really useful and clear. I consider myself learned.