rix

On those 10% - 13% highway grades, the engine braking alone doesn't keep the vehicle speed down, but it helps; it definitely helps. In my experience, it is quite aggressive in tow/haul mode. There are hills that my truck shifts down to 5th to go up, but it shifts into 2nd going down the same hill on the return.

Tystevens

Well, like I mentioned previously, one of our favorite spots is at 10,600 ft elevation; the climb is from 5000-10,600 over about 15 miles. So lots of steep winding roads.

The EB does just fine on this, coming up and going down with our 6500 lb travel trailer. I can come down the grade only using the brakes a few times. Lots of 1st and 2nd gear and high rpm, sure, but it does as well as, say, my GM 5.3 does controlling the downhill speeds.