I only use Toyota OEM Long Life Coolant. These engines were made to run with that coolant and not Super Long Life Coolant. SLLC contains sebacic acid, while LLC contains benzoate instead, which is a more traditional corrosion inhibitor. Basically some of metals inside our radiators can be corroded away from SLLC, while LLC has the ingredients to keep corrosion minimal. SLLC was made for newer Toyota engines and should only be used on those (4th gen +).