Thanks Dane, still wondering if that is true with the 15w40 oil choices in the 7.3's (Delo/Rotella/Delvac/Valvoline PB)
It can be and the reason why is this. All synthetics are a base stock with an additive package. What seperates the brands are the additive package. When you add one individual additive it effects another. Brand V may put an extra shot (so to speak) of the additive that fights shearing, by doing that they may degrade the ability to hold viscosity with another additive. That is why you will see many brands choose something wear, shear stability, viscosity, the ability to combat high temps, additives to make the oil more slippery in effect raising the fuel mileage but sacraficing something else to do it.
This is why I chose Amsoil. The products they make are the best compromise in additives making their product perform near the top in all tests and not the top in one test then falling to the bottom 3 in the next.
I can give you a link to read a gear oil White Paper and you will see how this plays out in the test results. There is one test with Amsoil products that you will hardly ever see another oil beat Amsoil and that is the 4 ball wear test.
To me wear is critical to the life of our 14,000 dollar diesel engines. That is why I use a FilterMag and Amsoil products and why I became a dealer of Amsoil products. My research told me these were good things that actually pay off in the long and short runs and save me money in both the long & short runs.
Dane
