No Mate, Disco box gives you higher output ratio IIRC about 1.4 at the output for 1 at the input, compared to 1.2 output for 1 of input on a defender (military ones are even worse). It will rev lower, this may mean you have to change down sometimes when you are going up steep hills at lower speeds, but otherwise much better. Ashcrofts are the people to talk to though and they're really helpful.