I was wondering if it was hard on the engine or transmission to use it as an aid in braking. When coming down a steep hill, if I step on the brake slightly the transmission will downshift and my rpm's can go up to between 4000 and 4500. Of course the same is true when we climb a steep grade. We can sometimes run at this high rpm for five or ten minutes. Am I being to hard on the engine/transmission? I might add that we are also towing a Honda CRV. Thanks for any input.