After 1,700 miles with ARX in my 2.8 V6 Audi engine I'm anxious to begin the ominous rinse phase. The oil currently in use is M1 5W-40, which according to Terry, is fine for the cleaning phase. Please help me choose the perfect oil for the rinse phase. I want to use an XW-40 oil with an HTHS of preferably =/>3.9. I was thinking of using Delo 400 15W-40. Please suggest some other oils. My knowledge of mineral oil is not up to snuff!