Anyone done one on there Z yet? I was debating changing the coolant and using one of the following:

Havoline Extended Life (nitrite-, nitrate-, phosphate-, silicate-, borate and amine-free formulation)
Peak Global (Formulated for use in all American, Asian and European automobiles -- phosphate free)
Nissan OEM (green, silicate free)
Toyota OEM (red)
Honda OEM (blue)

Just curious if there is any benefit (cheaper/better protection/better cooling) than OEM. Havoline seems to have a lot of good things going for it, but can't make a comparison against OEM because I can't find any documentation on OEM.