So I just bought a 2008 GL450 with 140K miles, Car looks, runs and drives as new. The car has a sticker at the top of the windshield from the last oil change indicating the car has about 3000 miles till the next oil change is due. I looked at the oil and it was black and smelled like gas. I can't imagine going another 3K miles on this crap, as I call it. The oil was like black coffee. The last oil change was done at a Pennzoil service location, according to the sticker. The oil filter I removed from the car said on it, "Made In Korea". WHAT!!! I became even more unimpressed. Nothing against the people of Korea, but I always use MANN oil filters, and I trust no one well enough to do an oil change on any of my cars, that includes four Benzes and a Maserati. If you take your car to an oil changing facility, I would recommend asking to see what oil filter they are going to put in your engine. Maybe I'm too picky, but hey, Mercedes Benz are supposed to be special cars, for special people, and I can tell you that mine get the best care. I buy the Mann filters from Amazon, cost is around ten bucks. Now, the oil I use, Mobil 1 is good enough but I use Liqui Moly which I also get from Amazon. Not trying to advertise here for Amazon, but I find the auto parts stores have employees that I find a bit..... well, Never mind!! Of course there are opinions for both sides but I prefer using a Mighty-Vac to suck the old oil out thru the dipstick tube, it's quick and easy, then just replace filter and add new oil. Twice a year regardless of miles driven. Never had a problem. Happy Motoring!