First off let me say I was very impressed in the performance improvement in my ’76 Thunder Bird (460 CI engine). I bought it new, presently 72,000 miles. Since the B-12 Chemtool, it runs better than it did new. Being a retired airline pilot, 31 years with US Air, I’m very concerned about perfectly functioning fuel systems and engines. The performance change was great as he said it would be. Now it performs like a DC-9 (my favorite airplane).