Mountain Driving Questions

[cinderella]

Hey, ya'll.

2017 Challenger 38" (automatic transmission) owner here. My husband and I have looked in our Ford owners manual and the overall manual that came with our Challenger and have also tried to look online and cannot seem to find an answer to these questions:

What is the proper way to drive through mountains with regard to taking the best care of your brakes/engine as possible? Based on my research, I have concluded that I should approach a downhill grade going fairly slow (40ish) and if I need to hit the brake, hit it hard to reduce speed 5 mph or so (at this point the RPMs increase to help the engine slow down so I don't have to keep hitting the brake so much) and try not to brake more than once a minute. There is no redline on the RPMs dial, but we never push that above around 4000. We want to do what is best for the engine and for the brakes, but we can't seem to find any further info on this.

Also, what are the 1st, 2nd and 4th gears for? Can these be shifted to on the fly? Or must one stop the rig to put it into one of these lower gears during climbing or descending mountain hills? Thank you for your advice!! Sorry if these questions are stupid. But I really have tried to research and am not coming up with much beyond what I've stated above. The runaway truck signs scare the heck out of me and we don't want to be one of those guys!

[JamieGeek]

They all have automatic transmissions.

If you are not pulling a toad just drive it. When going downhill you can put it in Tow/Haul (tap the button at the end of the shifter) and then you can just tap the brakes to get it to downshift--don't worry about it redlining: the computer will prevent any damage to the engine.

Once back on level or ascending you can take it out of tow haul.

The engine/trans are pretty bulletproof so no need to baby it (they've both been built by Ford for a long time).

[Bob Denman]

I agree: "Tow/Haul" Mode is your best friend!

[TurnerFam]

it works the same whether in ‘tow’ mode or not, that just causes the trans to shift sooner if you are towing something

i’ve delivered these to dealers with my tow car behind, and never have had the need to use ‘tow’ mode, but tapping the brake pedal when descending steep grades will trigger the trans to downshift on its own, similar to an exhaust brake on diesels

[JamieGeek]

Depends on the model year: Older ones would only downshift with T/H on, newer ones just do it all the time. Granted: OP is talking 2017 yeah..

[SuperD]

Many of the 2016 and 2017 models require an ECU flash update in order to shift correctly. Our coach would not downshift when it was delivered, since I knew I was going to install a 5 Star Tune I did not get our coach flashed, the tune took care of the problem.

[Beau388]

Originally Posted by cinderella

Also, what are the 1st, 2nd and 4th gears for? Can these be shifted to on the fly? Or must one stop the rig to put it into one of these lower gears during climbing or descending mountain hills? Thank you for your advice!! Sorry if these questions are stupid. But I really have tried to research and am not coming up with much beyond what I've stated above. The runaway truck signs scare the heck out of me and we don't want to be one of those guys!

The redline for all V-10s is 5,200 rpm. The engine's computer will not let the engine exceed that rpm under any circumstance. I.E. if you put the transmission into 1st and floor it, the engine will accelerate the coach until the engine reaches about 5,100 rpm then the computer will manage the rpm so that it stays below 5,200 rpm even though your foot is still on the floor. Your coach has an electronic throttle. There is no physical connection between the foot throttle and the throttle body.
If you plan to go down a 10% or greater grade, it is best to slow to about 20 mph and shift into 2nd and proceed carefully down the grade. You can select any gear manually at any time and you will not hurt the transmission or the engine at any time. Ford has been using the V-10 in it large trucks and RV since 1998 and six speed transmission behind diesel trucks since 2011, so they have experienced every eventuality. If your foot is completely off the accelerator and the coach is still accelerating a firm press on the brake petal will cause the transmission to down shift. If the forced downshift would cause the engine to exceed 5,200 rpm, the transmission will not downshift.
Tow/haul mode simply reschedules the up-shifts and down-shifts holding in lower gears longer and increases the internal pressure of the transmission giving firmer/quicker shifts

[captmetal]

i just traveled (in june) (thor outlaw 37 ls ford f53) over some 10,000 ft pass's in the rockies, i go slow average 25-30 mph down the hill, i use tow/haul for braking but do not over rely on it or the brakes, using a balanced combination of both i still had to stop twice cause the brakes were overheating.

if you survive a brake failure or loss of brakes due to overheating, your vacation is ruined trying to find a shop to do your brakes and then the cost of a emergency brake job. the tow maybe covered by good sam or other program but the brakes are a wear item not covered by any warranty.

and for all who think i am to cautious, count the dents in the guard rail down your next mountain pass.

[Mel556180]

Originally Posted by captmetal

i just traveled (in june) (thor outlaw 37 ls ford f53) over some 10,000 ft pass's in the rockies, i go slow average 25-30 mph down the hill, i use tow/haul for braking but do not over rely on it or the brakes, using a balanced combination of both i still had to stop twice cause the brakes were overheating.



if you survive a brake failure or loss of brakes due to overheating, your vacation is ruined trying to find a shop to do your brakes and then the cost of a emergency brake job. the tow maybe covered by good sam or other program but the brakes are a wear item not covered by any warranty.



and for all who think i am to cautious, count the dents in the guard rail down your next mountain pass.

What he said! RVs are big trucks, and should be driven accordingly.

[Richard]

A good rule of thumb is if you had to use 4th gear to climb the mountain be prepared for 3rd going down. Transmission electronics will prevent going over engine redline but you must then maintain your speed below the redline point. You’ve got lots time so be prepared to take it easy down the mountain. Be particularly concerned of any grades 7% or greater. Remember you are driving a truck and not a car.

[DenverTransplant]

We have taken our 2017 ACE over the I-70 tunnels and Vail Pass multiple items with a toad. We use tow/haul mode (but did have to have the ECM flashed to fix the no downshift problem). Going up we do 35-40 MPH with RPM’s as high as 4500. Going down same thing. Tow/haul downshifts when you tap the brakes and generally holds us at 40-ish. The engine is running at 4000 to 4500 just about all the way.

I do have to occasionally hit the brakes going down, especially going down the west side as its a long, steep grade. I slow down to 5-10 MPH below what is comfortable and then let the coach speed up before hitting the brakes. Vail Pass is also pretty steep going down the west side, but with more curves. The first time we did I-70 we hadn’t had the ECM flash done and the brakes got pretty hot. Wouldn’t want to do it that way again.

Going down the east side isn’t as bad. The grades aren’t as steep, but it is a longer pull with some flats and climbs. Curves aren’t bad, except for east of Idaho Springs as you go through the tunnels and weave your way along Clear Creek until you hit the climb up Floyd Hill. We’ve made it down from there hardly having to touch the brakes at all.

Some Colorado passes aren’t as nice. Highway 40 over Berthoud Pass has a bunch of switchbacks and some pretty steep climbs and downgrades so its a lot slower. You can make it as the road itself is good road, just slower than everyone else. Monarch and Wolf Creek passes in the SW part of the state are also curvey and steep in places.