Hello All! I would like to revive this thread! I read everything posted here, and several other resources online after reading my Ford E450 Super Duty and my motorcoach user manuals. I am going to be traveling from Colorado Springs to the Black Hills National Forest in South Dakota, near the Wyoming border.
I am also very new to RVing and have only taken the rig on mountain roads twice. The first time I drove it in the mountains I was driving from Colorado Springs to Phoenix Az using I-25, I-40, and I-17, which has several 6 and 7% grades, both up and down. That trip went great! I did not do any down shifting, just anticipated the hills going up and down. I was not using the tow mode but did use cruise control off and on through the hills. I did not need to use the brake excessively, pressing the brake for about 20 seconds would slow the rig enough to be safe and for it to downshift. The transmission never got hot, nor did the brakes.
The second mountain trip did not go as well, due to the closure on I-40 East. I was traveling from Phoenix to Colorado Springs and took 87 out of Phoenix, then 260 till it ran out, I forget which route next, and then many, many miles on Route 60 in Az and NM. I finally got onto I-40 just east of Grants, NM.
The engine seemed to be laboring going up hills (about 3000 rpms) whether cruise control was on or not. The brakes never got hot, when I used them briefly to slow to safe speeds, the rig would downshift, as on the other trip, BUT the drive train (?) was getting hot. The floor and console near the center of the cab was getting warm--I could feel it on my feet and legs. I stopped using cruise control very early into the trip because of gusty winds.
It was very windy in Az and Nm, I drove very long stretches at 45 mph with flashers on, just to keep the rig on the road. Not sure if this played into the heat in the cab from the floor and console, it was mostly cross winds, not head winds.
I stopped and turned off the engine for 15 to 20 minutes when it felt warm, but this situation (warm floor, cab over drive train area) persisted for the duration of the trip, until I crossed the border into Colorado.
In any case, I'm not sure about down shifting the rig, using tow mode, etc. for the next mountainous journey. My motorhome is gas not diesel, it does not have an OD button or switch, and besides P, N, D, it has 4, 2, 1. The manual only addresses 3, 2, 1 and says nothing about using those gears for going up or down hills. It says 3 is for improved traction on slippery roads. It says 2 is to be used to start moving on slippery roads, and 1 provides maximum engine braking, and allows upshifts by moving gear shift lever.
The manual includes the following on Forced Downshifts: allowed in Drive with tow/haul feature off; press the accelerator to the floor; allow the transmission to select an appropriate gear.
Tow/Haul mode info: Delays upshifts to reduce the frequency of transmission shifting; provides engine braking in all forward gears, which slows your vehicle and assists you in controlling your vehicle when descending a grade; depending on driving/load conditions, may downshift the transmission, slow your vehicle and control your vehicle speed when descending a hill, without pressing the accelerator pedal. The amount of downshift braking provided varies based upon the amount you press the brake pedal.
Based on what I have read and what my manual says about tow/haul mode, I am inclined to use that feature while anticipating the hills and using the same approach as I did on my first mountainous trip. I'm not sure what made the second trip so much harder on the rig, but want to avoid that as well as any safety issues.
I am not towing anything and would be surprised if the load is more than 400 lbs. My main question: does anyone have thoughts or ideas about why the engine seemed to be laboring more to climb hills when I drove on the back roads in windy conditions? I assume the laboring is why the console and floor were getting warm . . . All thoughts and insights are appreciated, as always!