My mechanic, also long-time in local racing is an Amsoil dealer, so obviously I use all their oils and other fluids in the Mini and my other car. They have one of the best reputations in town for reliability and honesty in this industry. They aren't cheap though.

Anyway, I quizzed them why and when they went with Amsoil. The answer was the racing. Engines, transmissions and rear-ends that would overheat and fail after a race or two, immediately began holding up, and failures were rare after they replaced the fluids with Amsoil.