Have you guys ever heard of AMSOIL they basically invented synthetic oils years ago before anyone else had it. 100 % full synthetic motor oil , I use it in my Mercedes and it is good for 25.000 miles per oil change, GUARANTEED amazing product they can even test your oil say at 20.000 miles by a independent lap to prove it is still good, but you do need a special oil filter with nano fiber technology that can handle the extended drain cycle which AMSOIL also makes. If everyone used these SUPER OILS our oil prices would go way way down . Not only that they are much better for your engine since synthetic oils almost totally eliminate engine wear due to there extreme anti friction properties , I was in Germany on holidays a few years a go and I rented a brand new BMW for the autobahn anyways the digital computer said next oil change in 30000 km , the oil is full syntetic right from the factory when it is built thats why ...