Prestone has not sold the traditional green silicated antifreeze for a long time. It's the "All makes" Dexcool clone now. I'm not sure about the shelf life of the inhibitor. But > 5 years I probably won't use it. You can call Prestone and ask for a more accurate answer. Can't remember from reading posts.
The Toyota super long life coolant, Zerex Asian Vehicles coolant, Peak Global are all organic acid type coolants that use phosphates in place of the problematic plasticizer 2EHA acid used in Dexcool. If you have the 5SFE bi-metal engine (aluminum head and iron block), then I'd stick to the Toyota Red every 2 years/30K miles.
Besides, you'll have the hang loose plastic vacuum valve on the radiator cap that lets air in. Organic acid type coolants hate that and can turn to gel when air is in the system.
The silicated old green is excellent in bi-metal engines and so is the G-05 low silicate coolant. However, if there is cheap rubber pump seal in there then silicates will wear them out much sooner than pumps with carbide seals. Most Asian pumps come with less expensive rubber seals, so they require no silicates in the coolant.
Originally Posted by dave52
Have an unopened gallon of the green prestone concentrate antifreeze. Can I use this in my 97 Camry for a coolant flush or do I have to get the official Toyota antifreeze at the dealer $$$??