Last month I installed the Dimple Plugs on my e39 535iA. The car has 349K kms on it and I change the oil every 10K to 12K kms. I bought the car with 243K kms on it. I use Mobil-1 0w40 LL1 oil(US oil) in my e39. I use about a quart of oil every 8K kms.
I was really surprised on how much metal particles the Dimple Plug picked up. I will be installing the Dimple Plug on my 135i in a week or so - time permitting.
Anyways... check out my photos!
