My engine builder turned me onto it, he only uses amsoil and he isnt a dealer. I was using royal purple at the time and made the change. I did a test on the RP with oil fortifier and it came back satisfactory. But after being around the diesel and car community for awhile basically every test i have seen is that amsoil is better than RP. Then adding to my logic is this, fords main money maker is cars, not oil. Amsoils only game is oil, so i would bet that it is better than motorcraft.
Also consider that most oil brand’s tech has gotten so advanced over the recent years that it really wont matter what brand you use, as long as you use a reputable brand (not amazon, not sahabeebs), and stay with the oil change intervals. Will the OP notice any difference between off the shelf vs amsoil? Probably not. Will it make a difference in the life of his truck? Probably not. Is amsoil “better” than off the shelf? Probably, just comes down to if you think the increase in performance (however much may be) is worth it to you.
As for being on Ford’s magic list, manufactures have to pay Ford to test it to get it on the list. My guess is amsoil didnt see the need to do that, but rather have the customer make the call instead. Look on the Ford list, you got guys like “valuetech” on the approved list. Look that one up and tell me if you would prefer that over amsoil. I wouldnt even put that in a push around mower.
I only use amsoil because it makes me feel better about myself since i own a 6.4. Gives me a false sense of security.
Here are some links for tests if anyone is interested, independent tests only
What are the results of Royal Purple vs Amsoil test. Who ends up as the winner?
myengineneeds.com
JCW Garage - Synthetic motor oils testing results - All synthetics are not the same. Which is best? I leave up to you. Properties need to be considered to make an educated decision. Good lab testing is essential and here is good lab testing for gasoline engines: What is the best synthetic motor...
www.northamericanmotoring.com
