I've used just about every brand of oil I've seen at the stores. LOL. When I first bought my car I was using BMW oil, then I switched to finding BMW LL approved oils, then when I saw sale/cheap prices for 5w30 I'd get that and one thing led to another and now today as long as it's synthetic oil, I just put it in. In my garage I have a combo of Noname 5w30, Mobil1 10w-40, Castrol 10w-30. They all have certifications on them but I don't pay much attention to them anymore. I just grab whatever is closest to me when I'm doing a top up. My main base in the engine right now is Motul 8100 5w40. Some say my practice is a ticking time bomb, but I don't see it when I look into my bare engine, how it drives on the road, the fuel economy, performance, etc... My dad is the same with his '97 540i that has more mileage. My sister's '01 Audi A4 hasn't had a problem either. North America is sold on brands because of how it makes us feel when others use a "lesser" brand.
If most engine oils on the shelves today were made for a specific use, and only one use, I'd think oil manufacturers would be getting sued up the behind from customers who have absolute no clue about what to purchase because the internals of their engines broke from wear. But the petroleum product companies are still in business today making enormous profits! My car is happy whether is gets Tier 1, 2, or 3 fuel. I'm not too fussy about what goes in it as long as the station is the only one with super old pumps and noone refueling at that station when busy Chevron, Shell, and Texaco are next door.
Last edited by rovert; 10-10-2012 at 04:39 PM.