that being said, NAD is so ubiquitous that I can't imagine it is the only factor. It's may be more akin to saying if you use Chevron gas with techron vs. Arco

that being said, NAD is so ubiquitous that I can't imagine it is the only factor. It's may be more akin to saying if you use Chevron gas with techron vs. Arco gas, that your engine may last another 5,000 miles or something. But it doesn't address primary causes of engine failure based on design, engineering, etc.