[QUOTE=Grumpy;256724][QUOTE=Plowtoy;256683] Personally, I run the 21372, but we are changing oil every month and a half (5000 miles). I also use a heavier oil than what is recomended. I figure that the 5W20 is just too thin for what is expected of those engines (im no engineer though).
Ford uses 5W20 because of the close ring tolerances. You are probably doing yourself a disservice running the heavier oil. I was told to always run 5W20.
Originally Posted by The Logans
The last time I was at the Ford dealership they were replacing a 2013 V10 engine that the owner had put 10W30 in it. The shop manager said that because of the fine tolerances, and the small size of the oil ports that you MUST use 5W20.
I also can't find anyone to change the oil, so thanks much for the video!
I might just be lucky??? But I've been running heavier oil since I started working on these cut-aways (12 years ago). I have several with 200+ thousand miles on them, and 3 well on their way to 300000.
I've heard of the close tolerances, but as a mechanic, my brain works oppsite. A new (low milage engine) will have very tight tolerances (i get that), but as they get older, those tolerances will decrease (get bigger) there for, I see as an engine with over 50000 miles on it, will have more tolerance and can use the thicker oil, which takes up those tolerances.
I have also found that my consumption has decreased with thicker oil. I think that with the thiner oil, it is able to get past the rings and be burnt off the cylinder walls, where as the thicker oil gets cleaned off the surface better.
Just my $.02... Im sure Ford spent millions of $ to figure out what will get them the best mileage and EPA approval, but this has worked for me for hundreds of thousands of miles with no major mechanical problems...