Hi All,

New to this forum, so first post.

I was wondering about tyres after reading about the x-drive sensitivity:

• I have a 2007 e83 30SD running the standard staggered 235/50R18 in the front and 255/45R18 in the back.
• It became rapidly clear why the previous owner sold the car to the garage as two weeks after buying it the trifecta of lights came on. I changed the transfer case fluid and replaced the actuator nylon wheel and all is well. I suspect the previous owner put wrong winter tyres on it and upset the x-drive system and then replaced the summer tyres on it and quickly sold it...
• I bought the car with winter wheels which are a square setup: 245/45R18 Pirelli Soto Zero (not * rated).
• The winter alloys are also 8Jx18H2 ET45 when I believe the original BMW summer wheels are 8Jx18H2 ET46.

Would anyone be able to advise me on what to do:

• Can I run these winter wheels as they are, or should I replace the tyres to the recommended square 235/50R18 on the same alloys?
• As far as I can tell there are no longer any * rated winter tyres available (Dunlop SP Winter Sport 3D). Which tyres are proven to work?
• Does the 1mm offset difference in the alloys make any difference?
• My summer tyres are Dunlop SP1, which are the only recommended * rated tyres for the staggered setup. When I run it through the wheel size calculator, I get a diameter difference of 1.2%, which seems large... Should I run a square setup my next tyre change? Strange that BMW would recommend such a setup on the notoriously sensitive x-drive system...
• I love the Michelin Primacy 3 tyres (and the Alpin 5 winter tyres), but they are not BMW rated, but I suspect they could be ok in a square setup, is this true?

Thanks for your input,

Dan