3000GT Coolant: Safe to Use Zerex G-05

I have a 1991 3000GT and have flushed and filled using the traditional green
ethylene glycol coolant every two years. (This seems to have worked out
well since even though the vehicle has 135K miles, the cooling/heating
system is entirely original equipment, with the exception of the water pump
which was replaced as a preventive measure.) In my newer vehicles, I use
Zerex G-05 coolant which only needs replacement every 5 years. Does anyone
know if there is a reason why I should not use the G-05 in the older
Mitsubishi 3000's cooling system? Thanks.

Bob