Diesel Water Wetter coolant additiveSame improvements in cooling efficiency as Water Wetter, but without the rust and corrosion inhibitors. Designed for heavy duty diesel engines which use more than 33% antifreeze. Its cooling system heat transfer agent for use with antifreeze water solutions improves the ability of coolant to wet heat transfer surfaces by 50%. This provides significantly better coolant contact in the cylinder head and can reduce coolant and cylinder head temperature by