Originally Posted By: Flareside302
I look at it this way. in certain applications. G-IV/G-V is better. like racing or a serious built engine that gets beat on as a daily driver...
the better the base stock to start building with, IMO using the right Additives you'll have a much better oil than any G-III could dream of. and that for me is enough to be a Amsoil Signature series fan, and dominator line fan.
but g-III oils have they're place.
Seriously built engines?
I'd argue that applications like the Ford Shelby GT500, GT1000, the ZR1, basically anything wearing an AMG or ///M badge, the GT-R, Porsche....etc are the most demanding applications. They have to make that kind of power and continue to do so for well beyond their warranty period to retain their prestige.
And the common thread with those applications is that they are covered by a manufacturer cert/approval process. There's no requirement for a specific base oil, there is a requirement for a specific level of PERFORMANCE.
Oils like M1 0w-40, PU 5w-40, these oils meet the performance requirements for most of those applications yet do not meet your personal definition of "better" because they are not predominantly G-IV/V.
Porsche uses M1 0w-40 in their race cars, as we've had confirmed on here multiple times. GM uses it in their Corvette Race Program cars. This seems to rather boldly contradict the premise of your post.