Mountain Driving Tricks

[dkoldman]

I have searched this site but most questions seem related to big Diesel Pushers? Clue for me is I may not need to worry

But I am planning my 1st trip through some basic mountains, nothing too steep but mountains nonetheless.

I have new 2019 Sunstar 29VE (7k miles) F53 with Drive & Overdrive capability. It also has 4, 2, 1 gears (on steering column anyway) NOT the 3, 2, 1 gears that are in my manual

The Ford manual says ABSOLUTELY NOTHING about Mountain driving

It says use D to drive like normal ( well alrighty then )

It just says use Overdrive if you wise to engage all gears automatically?
It says use 3rd gear for slippery roads? ( I don't have a 3 gear)
It says use 2nd to start up on slippery road?
It says use 1st for maximum engine breaking? But it also says if you driving don't go to 1st? So I assume you need to stop or slow down real slowly then go to 1st to to do engine breaking

Surely this can't be this hard.

What is normal to do assuming I drive like normal in Standard D gear?

[Old Scout]

...think the "tricks" should be similar: 1-keep RPMs up on climbs; 2- start downhills at low speed, shift down early and as appropriate to maintain that speed, use service brakes sparingly....start out under control and finish the down grade the same way.....you don't have exhaust or engine jake brakes on gassers so maintaining control and preserving service brakes is paramount on down grades....

[dkoldman]

Originally Posted by Old Scout

...think the "tricks" should be similar: 1-keep RPMs up on climbs; 2- start downhills at low speed, shift down early and as appropriate to maintain that speed, use service brakes sparingly....start out under control and finish the down grade the same way.....you don't have exhaust or engine jake brakes on gassers so maintaining control and preserving service brakes is paramount on down grades....

Thanks I have 6 hour trip tomorrow. I know of at least one tunnel; so I will ensure the fridge and heater is off when I drive through it.

But let me try to put what you said in layman turn so my DW can understand

Do I even bother with Overdrive? (These are Boston Mountains in NW Arkansas.

Assuming I drive regular with "D" Are you saying when I start to pull a hill and rpms drop to ( i.e. 2,000 rpms) I should go to Gear #4?

Stay there assuming I am in 3,000 - 4000 range? If I am still at 2,000 RPM or lower drop to Gear #2? I am not going to Rocky Mountains so I don't think I will see anything that would force me to go to Gear #1?

On the other side (down hill) I think you are telling me to drop the gears up maintain where I am at to get up the hill until things level out. I would go 4, to 2 to 1? Intent to stay off brakes as much as possible.

Bonus Question What happened to gear #3? Did Ford reasoned that a Gear #4 was better or cheaper to have than a gear #3?

[Goodspike]

I'm not at all familiar with your system, but do want to ask if it has a tow/haul mode? That would be the first thing.

Second, I can't imagine you'd want to allow the transmission to shift into overdrive, so I wouldn't select that.

The last thing I'll offer in my ignorance is don't worry too much about the engine reving up somewhat near whatever your redline is. If the engine can handle that under power it can handle that under vacuum.

Actually I will offer one last thing. On some vehicles cruise control will help maintain a speed, downshifting the engine. You might give that a try on a smaller hill first.

Again note none of this is specific to your vehicle.

[l1v3fr33ord1]

dkoldman-

Put the transmission in "D" and leave it there.

At the start of the grade, going up, put the coach into Tow/Haul mode. Leave it there until you get down the other side of the grade. Some people leave it on all the time.

As you come downhill, and start to gain speed, press the brake pedal quickly and the transmission will downshift for you- once per press.

That's all you need to do. No manual shifting is required. The Ford transmission programmers have done all the work for you.

PRND421 means your coach has the six-speed transmission, first installed in 2016 model-year F-53 chassis. The manual's PRND321 reflects a five-speed transmission, which would be incorrect for the 2018 or 2019 model-year chassis on which your coach is built.

[dkoldman]

Originally Posted by l1v3fr33ord1

dkoldman-

Put the transmission in "D" and leave it there.

At the start of the grade, going up, put the coach into Tow/Haul mode. Leave it there until you get down the other side of the grade. Some people leave it on all the time.

As you come downhill, and start to gain speed, press the brake pedal quickly and the transmission will downshift for you- once per press.

That's all you need to do. No manual shifting is required. The Ford transmission programmers have done all the work for you.

PRND421 means your coach has the six-speed transmission, first installed in 2016 model-year F-53 chassis. The manual's PRND321 reflects a five-speed transmission, which would be incorrect for the 2018 or 2019 model-year chassis on which your coach is built.

This is perfect, I will print this out and add to my manual and put in my SOP I keep for my RV. I wonder the odds of Ford sending me the correct manual?

Look forward to trying this tomorrow.

[dkoldman]

Originally Posted by Goodspike

I'm not at all familiar with your system, but do want to ask if it has a tow/haul mode? That would be the first thing.

Yes, it does. I will use tow/haul mode when I get to the mountains. If you read the manual it it reads as if you only use tow/haul mode when your are towing or have a trailer

[macnut]

Originally Posted by l1v3fr33ord1

dkoldman-

Put the transmission in "D" and leave it there.

At the start of the grade, going up, put the coach into Tow/Haul mode. Leave it there until you get down the other side of the grade. Some people leave it on all the time.

As you come downhill, and start to gain speed, press the brake pedal quickly and the transmission will downshift for you- once per press.

That's all you need to do. No manual shifting is required. The Ford transmission programmers have done all the work for you.

PRND421 means your coach has the six-speed transmission, first installed in 2016 model-year F-53 chassis. The manual's PRND321 reflects a five-speed transmission, which would be incorrect for the 2018 or 2019 model-year chassis on which your coach is built.

Great advice. The only thing I will add to it is if it’s a steep hill, say 6% grade or more, start down the hill no faster than you went up the hill. In fact, I usually back off a bit as I near the top. That way, when I start to transition to downhill I can tap the brakes and the tow/haul mode will go into a lower gear right away and allow me to use the brakes less going down the hill. Some times I tap the brakes another time or two to get it into an even lower gear. Of course, the lower the gear the slower you need to be going for the tow/haul more to do its thing.

I can go down a steep 7% grade towing my CRV going about 35 and hardly ever have to tap my brakes. Since all RVs vary a bit in size and weight, your experience may vary, but after a few grades it will be easy.

[sanda]

Originally Posted by l1v3fr33ord1

dkoldman-

Put the transmission in "D" and leave it there.

At the start of the grade, going up, put the coach into Tow/Haul mode. Leave it there until you get down the other side of the grade. Some people leave it on all the time.

As you come downhill, and start to gain speed, press the brake pedal quickly and the transmission will downshift for you- once per press.

That's all you need to do. No manual shifting is required. The Ford transmission programmers have done all the work for you.

PRND421 means your coach has the six-speed transmission, first installed in 2016 model-year F-53 chassis. The manual's PRND321 reflects a five-speed transmission, which would be incorrect for the 2018 or 2019 model-year chassis on which your coach is built.

I have to disagree with you on the downside suggestion. If you let the trans computer do all the downshifting you will end up running very high RPM's. I tow often over the mountains of Colorado. Manually downshift to a low enough gear to safely hold the speed. Occasionally tap the brakes to maintain that speed. Keep an eye in the mirrors for traffic and pull over when you can and let them go.

[twinboat]

Originally Posted by dkoldman

Yes, it does. I will use tow/haul mode when I get to the mountains. If you read the manual it it reads as if you only use tow/haul mode when your are towing or have a trailer

You are hauling.

Ford built the bare chassis, someone else added what your hauling, a heavy house !

If it was an emoty, flat bed truck, then you wouldn't be hauling.

I turn on Two/Haul when I start the Motor home.
I also set the cruise control on highways. With CC set, it upshifts and downshifts automaticly going uphill and downhill, without me needing to touch the gas or brake pedals.

Don't over think the transmission shifting, let the engineers, who built it, do that.

Don't worry about the high RPMs, that engine is built to run above 5000 RPMs.I often see 5200 RPMs on mine in real steep hills.
If it gets to high, it will shift and not damage the engine. At that point, your must be just about driving off a cliff.

Get on the road put it in D, set the CC and give it a try.

[dkoldman]

Originally Posted by twinboat

You are hauling.

Ford built the bare chassis, someone else added what your hauling, a heavy house ! I got this visual of me driving my house pulling my 24 ft boat to the lake Now that would be hauling

If it was an emoty, flat bed truck, then you wouldn't be hauling.

I turn on Two/Haul when I start the Motor home.

Are you saying you use tow haul all the time regardless of mountain driving or all the time when you know you are going into hills or mountains?


I also set the cruise control on highways. With CC set, it upshifts and downshifts automatically going uphill and downhill, without me needing to touch the gas or brake pedals.

Don't over think the transmission shifting, let the engineers, who built it, do that.

Don't worry about the high RPMs, that engine is built to run above 5000 RPMs.I often see 5200 RPMs on mine in real steep hills.
If it gets to high, it will shift and not damage the engine. At that point, your must be just about driving off a cliff.

Get on the road put it in D, set the CC and give it a try.

I have use the Cruise Control before, (just not in mountains) and I've felt what you are talking about. It does kick in on the hills and slows itself down just from normal interstate driving. My knock on Cruise control has been the other traffic It seems like cars flying by at 100 mph just enjoy getting right beside me to slow down and wait until I am about the to run into car ahead forcing me to brake and killing the cruise; then they take off. The resume will get me back going though.

Trying to visualize driving on cruise in mountains though, speed limit will vary widely from about 40 mph to 70 mph

[Goodspike]

Originally Posted by dkoldman

Yes, it does. I will use tow/haul mode when I get to the mountains. If you read the manual it it reads as if you only use tow/haul mode when your are towing or have a trailer

LOL. You might want to use it in more than the mountains. It really depends on the vehicle and your total weight. It can also help with shift points when going varying speeds in slower traffic, etc.

[Goodspike]

Originally Posted by dkoldman

Trying to visualize driving on cruise in mountains though, speed limit will vary widely from about 40 mph to 70 mph

Well realize that going down a very steep grade with a heavy vehicle you do not want to be going too fast because you want to avoid hitting the brakes as much as possible. They can heat up and fail. So if you know you have a 40 mph turn coming up, you probably don't want to be going 70 or even 60 within a mile or so of that because you'll probably have to use the brakes to slow down.

A good example of that is the west side of Steven's Pass (Hwy 2) in Washington state. Heading west the downgrade is quite steep, and while the road is two lanes going down (and two up) the first three or so miles, at the bottom of that 4 mile stretch there's a 40 mph corner. I try not to exceed 50 getting to that point.

Map of corner:
https://www.google.com/maps/search/s.../data=!3m1!1e3

Warning sign at top:
https://www.google.com/maps/@47.7462...7i16384!8i8192

[rarebear.nm]

Having grown up and lived most of life in the Rockies, I Feel I have some measure of our mountain roads.

I want to add a comment on using your service brakes. First I agree to use them as little as possible. In my diesel, my goal is not to use the service brakes at all on the decent. When you need to slow down for a turn do so in the straight away approach to the turn. Try to avoid braking while in the turn as much as possible. You have much better vehicle control when under power as opposed to when braking. This is important in turns and any non-dry road conditions.

As for letting the onboard computer do its thing vs. my staying in control, I prefer to take over for decent. Going upgrade the computer likely will do fine. Even so, I still prefer to take control for the upgrades as well. My objection with leaving the decent to the computer is it can not "see" what's ahead to make speed corrections in advance. Like a tight turn, a slow truck or any other condition that may require some kind of speed adjustment. The computer is very good at knowing the immediate condition not what lies ahead. Just saying from years of mountain driving...