On one of my tunes from Nelson. Mine was definately faster by the butt meter with it unlocked. I really liked the feel of the more power that way. But, I had to get mine to lock up cause I tow with mine. I didn't want it stalling around with a load behind it. Afraid it would be to hard on the trans, even though I have a bigger trans cooler on it. So I had to get him to reutne that part of it.