I currently run Havoline Dexcool (the orange stuff). I have not had any problems and I flush/fill (70 Water / 30 AF mix) every 2 years since 1998. Also, I only drive the SHO in the summer. Some forums I have been reading seem to all praise the G-05 anti-freeze. Original water pump at 125K too. http://www.valvoline.com/pages/products/product_detail.asp?product=10 Thanks, Chad L 92 Red