I was chatting with someone from Valvoline and I asked about a GTL base and also EP and Restore and Protect, they mention that they don't have a GTL base but a mineral oil base..
But with Valvoline R&P being $30 for five quarts, we may just be better off getting Castrol EP for the same price.. one may say that's a better oil since it's rated for 25k, and I believe it has more certifications..
I know Extended Protection Max life is a GTL base, it doesn't appear, that Extended Protection is a GTL base or R&P. From looking at the safety data sheets