Powercool is the Detroit antifreeze/coolant. You can get it premixed 50/50 or buy it straight and mix with distilled water. Nalcool is an additive you can use with distilled water but has no freeze protection. Penray makes a cleaning product for descaling the cooling system. I've used the 2 part cleaner with very good results. I've used the straight Powercool for over 12 years now. Once the system was cleaned, I never had an issue again. Detroit claims the powercool can be recharged and used for many years, providing the cooling system is clean.