I have a 1988 Toyota Corolla w/auto tranny that takes Dexron II. I would like to do a change or 2 of the fluid. At Walmart I see Super Tech Dexron VI that says it is compatible with Dexron II, and also another one that is Mercon V that says it is also compatible with Dexron II. Which one would be better in this case, or would it be better to get a name brand fluid?