What Race Oil do you trust?

[Bobby Fazio]

Reviving this thread to ask if anyone has given thought to Viscosity Index? As I understand it, the higher the VI number, the less the oil changes with temperature. In trying to be as consistent as possible in our classes- cold morning runs vs a hot laps, would it make the most sense to run oil with a high VI? I've noticed Royal Purple, Eneos, and Driven have high VI numbers.

I would also extend this question to ATF and Differential as well.