Prestone claims their product is compatible with all systems:
New Prestone Cor-Guard™ was the result of seven years of research and development at the renowned Prestone Innovation Center. The development team set out to improve existing technology AND to maintain Prestone's ability to work in any car and light-duty truck. New Prestone will not void your warranty and can be used to fill your radiator after a flush and clean or it can be added to your existing fluid to optimize your system.
Prestone | Cor-Guard