Well, I changed the oil in my 05 LT for the 6000 mile service. When I changed it for the 3000 miles, I used the BMW oil from the dealer. First thing I noticed is the bike ran rough. I thought it would go away but it never did. My gas mileage went from a consistent 44 mpg to 38 mpg. I changed the oil last weekend with Castrol 5W30 per recommendations on this site. I road to work today since it was 60+ degrees here in the DC area and my gas mileage went right back to 44 mpg. What gives with this BMW oil?