do that five year antifreeze,150,000 miles.really work.can you leave in,for five year.
Others will disagree but that’s the last thing I would do with a new car.
year, make model of vehicle?
I tried a 5/50 that was a DexCool clone, and it ate the O-rings that sealed my radiator end tanks to the core in two years (new radiator when I first put in that coolant). I will never touch that stuff again.
With all the fancy stuff they are doing with cars today, it is usually best to stick with the recommended products.
What will work with one make year and model of car will not work with another. So the best we can do from your original post is to give general advice. If we know it was a 1966 Ford, we might be able to be more specific.