HD TRUCK COOLANT Red is a premium quality, organic, long life anti boil/anti-freeze coolant concentrate. HD TRUCK COOLANT is based on carboxylate technology and contains no silicates, borates, phosphates, nitrites, nitrates or amines. It is suitable for both automotive and heavy duty diesel engines. HD TRUCK COOLANT contains 90% monoethylene glycol and a double inhibitor package ensuring ultimate corrosion protection and extended service life.