7 miles of an 8-9% grade downhill...WOW, you better have everything dialed in perfect. If it were me I'd do a few practice runs completely empty. Engine braking will work until the ground speed starts overrevving the engine and you have to start up-shifting to keep from blowing the engine up which decreases engine braking and increases ground speed...it's a slippery slope. Is there a run away truck ramp on that hill?
Mike B
