On a manual tranny, how hard is it on the tranny and motor to downshift to help slow down?? My friend's dad might be gettin a new bass boat, and said my buddy could take it to the lake whenever he wanted...problem is he has a lifted jeep wrangler w/ the 2.5L 4 cylinder and 5 speed...i know it can pull it...but im worried about it slowing down a boat that heavy...I would imagine that the boat will be about the same weight as the jeep itself, so im guessin it would be hard on the brakes...so im sure there will be times he has to downshift to slow it down within a decent distance...is it gonna be that hard on the motor and tranny to assist slowing it down this way??