ive tried X-1r on my starex. i didnt really notice much.but with the starex having an oil cooler the oil really doesnt over heat that much that it would lose its viscosity, but if you really want to protect your engine, then install a by-pass flter. just type bypass filters in google,and it will explain it all to u. i really want to install one in my starex, but i still dnt have any idea where to get it here in the philippines. i m still waiting for my parents to check out the prices in australia when they go there this december.