Hi: I bought your product after reading some comments about it. I used it for a 1979 Chevrolet C-10 with over 106,000 miles. It was leaking oil, so after removing the oil pan I noticed that at less than 1,000 miles the oil got very dirty. The cleaning was working! It really impress me since previous oil changes at 3,000 miles were not as dirty as this change. Great product! Sincerely, Jose from Georgia