[Christ]

Originally Posted by MetroMPG

The viscosity stability of synthetic gear oils should return better efficiency in cold conditions. It's an issue for transmissions/differentials, since they don't benefit as much from the heat of combustion as engine oil does.

I can find dozens of links that claim to support this notion.... but can I find one on short notice that appears to have some science behind it? Nope!

Anyone?

That's what I'm getting at. I've never seen/heard of a real benefit that was measured in a scientific sense, or couldn't have been explained by old fluid vs new, so I can't suggest in good conscience that there is any discernible gains from using synth over dino for the most basic of comparisons. Longer change interval isn't really even going to come into play, since many vehicles operate their entire lives on whatever fluid was installed at the factory.