Recently my 3800 v6 series II sprung an internal coolant leak due to an engineering defect which caused the upper intake manifold to warp. My car was going through, no kidding, 1/2 gallon of coolant per day. Before changing the intake manifold and gasket sets, I decided to buy myself a few extra days by getting an oil change. Someone recommended that I add some of your stabilizer. After doing so about a week ago, I have yet to loose a single drop of coolant. What a product!!! I have become one of your greatest spokesman on the streets. Also, thanks for the new stadium for my beloved Colts!