2003 M5 Oil Consumption

I recently purchased a very nice used 2003 M5 with around 34K miles on it. It appears to have been well maintained by the dealership I bought it from. I have noticed though that it goes through a quart of oil every 3 or 4 thousand miles. No leaks, and I have never noticed it smoking. Dealer says this is common for the M5. Is this true? Any recommendations on what motor oil to use in it to minimize this. Keeping in mind though that I am in Ohio, so winter is a factor. Any thoughts are appreciated. :rolleyes: