I live in Florida so I have the LUXURY of being able to dump ALL my cooling fluid and replace it with a mixture of 15 percent Glycol, distilled water AND WaterWetter. I have dropped engine operating temperatures significantly. I will be able to provide EXACT temps shortly but it looks about its a 20 degree drop. GLYCOL transfers heat VERY POORLY so the less you can use the better. IF YOU LIVE WHERE IT GETS COLD YOU MUST HAVE FREEZE PROTECTION. WaterWetter ADDS to heat transfer making the cooling system more efficient.