Ive tried this in 2 transmissions now. I am not sure it has done anything, as far as shift feel or quality. In the chevy the flare under heavy throttle is still there for the most part. In the toyota I added a half bottle tonight and just took it for a long local drive but didnt notice much difference, both with fresh maxlife. According to the bottle it cant hurt anything, and it can make the trans up to 40* cooler. The reviews on amazon make this stuff out to be magical. Maybe I need to give it more time? Put the whole bottle in the toyota?