Do not use summer tires where the temps. go below freezing regardless of snow conditions. Summer tires lose allot of traction when the temps. get cold because the rubber hardens, a dangerous condition.
If you don't want to swap out tires for winter your better off getting an A/S tire that leans towards dry performance over snow traction like the Michelin Pilot A/S plus but then you have the run flat issue since it's not available in a run flat version in our size. I had them on my Audi S5 and they were good in the dry and rain but just fair in snow.
What I'm thinking of doing like "djsilo" mentioned is getting a 45 series tire since I've had many bubble problems with the Goodyear LS2 245/40/19 tires. I'm looking at the Bridgestone Potenza RE-960-AS Pole Position run flat which comes in 245/45/19 and is a newer design run flat compared to the Goodyears. I'm not sure if BMW will honor my wheel and tire insurance though if i don't use the original OEM tire. Why can't this be simple.
ordered-2018 M550ix White, Mocha
2014 550ix Mineral White, Black
2015 X5 35i
Porsche 997 GT3
Porsche 993 Cab.
Porsche 996 Turbo (Ruf 550) gone but not forgotten
ordered-2017 Mustang GT350
Last edited by Diver624; 12-09-2012 at 10:13 AM.