Truthfully I think they are all a wast of money. They are allow cost band-aid to a high priced problem. I think they make most people feel like they did something to help the trany, a pacifier at best. I do not think there is any good short cuts around the automatic transmission. Keep your money and stick it in a jar labeled "Future Transmission Replacement Fund". Every time you pull a heavy load, tow anything, or race the guy next to you in the Ford to the next stop light, toss a twenty dollar bill in it. If it last long enough, might make a dent in the new trany to come.