What material is the Radiator made out of? The long life coolants do not work well with Copper and Brass soldered Radiators. If the Radiator is plastic and Alum the Long life stuff shouldn't hurt the Radiator.
Is your statement about extended life coolants a general statement or specific to some coolants?
This is from the Zerex website for G-05. It mentions all cooling system metals. Its approved by John Deere and other diesel engine manufacturers. I am sure many of those radiators are soldered copper and brass.
Valvoline’s Zerex
Ò G 05
Ò
antifreeze coolant is a long life,
fully formulated ethylene glycol-based fluid suitable for
passenger cars, light trucks and heavy duty vehicles. The
formulation is designed for both gasoline and diesel
engines. Its lower-silicate, reduced pH, phosphate free
European technology protects all cooling system metals,
including aluminum, from corrosion.