Originally Posted by former NXMX5
no way. no 15w50 at all. 0w40 only -- i have used it too; heavier oil used to be ok on a tired v8 to fill in for wear on parts, but with this engine i wouldnt try it --
7800K... you measure in kilometers?
No, its going to be about seven thousand eight hundred by the time I change it. Here's what I'm going to do since I bought that "extended life" Mobil 1 already. I'm going to go out and buy some 0w30 (case) and then add (2) quarts of the "extended life" oil to that, thus giving me pretty much the multi-viscosity I need after the blend. The rest of the oil is going into my wife's Ranier in the spring. I went from 12.5K to about 29K w/o changing the oil, I use Mobil 1 in that, but I did change out the filter at 7.5K and used a Mobil 1. Recently Buick offered us a free oil change under "customer appreciation" day, so I let them use regular motor, but in the spring, its back to Mobil 1 and only changing the oil filter. You may ask why I do this and its because of a book called "The 3,000 mile lie". It pretty much states when you run synthetics you only need to change the filter, using a quality one at that. The guy who told me about this and believes in it is an ex-Ford engineer from England who was the chief engineer for the Ford Contour back in the mid 90's. This guy is one of the smartest people I've ever talked to about cars, so I believe him.