I put a bottle of it my old truck a 95 dakota which made my tranny shift better. It even fixed a big slip between 2 and 3 too. But I got a tranny flush done and put synthetic in it. When they did the flush I had 0psi at idle and they said the fluid smelt burnt. Basically the fluid was shot and tranny ready to die. But after the flush the pressure went up to 18psi and shifted 10 times better than just putting in the lucas oil. I think a good ol tranny flush is way better than useing lucas to try and fix the problem.