Part of the problem with SCAs is that the mix ratio has to be right, and you have to maintain the levels - too low and it won't protect. Too high and it will actually eat copper itself, IIRC. This is why you have to dose it correctly and maintain that ratio. HD ELCs(G-05 and compatibles, etc.) use a different method for preventing cavitation, and don't have the "too high" level problem. This is why they can advertize a 5yr/300k mile coolant. (Also, Zerex's HD ELC offers a dose of the same additive pack that you can add at 5 years and extend the life again). Because I'm lazy - I just want to fill and forget for a few years - I chose the ELC coolant. I haven't seen anything wrong with either G-05 or Zerex's HD ELC as far as not protecting or eating any metals, so I can use it in anything.