I just bought a 2006 M7 with 820 miles on it... The person I bought it from said he has only run Blue Marble oil through it, but I have heard a bunch of people say they don't like this brand. I don't really like the idea of changing the brand of oil that has been going through since its bad for seals and stuff, but what are your guy's opinions on this..? Mainly from what I have read it seems like everyone who has used only blue marble in their machines haven't had any issues, but everyone that switched from a different type to blue marble has had lots of problems. Soooo what do you guys think...?