Driving in Mountains and Hills

[Jraulpilot1983]

I don't manually downshift going up hill. My transmission is a 6 speed and has the newfangled semi-auto thing where I could increment or decrement the selected gear. But I find it easier to just let the transmission do it's thing. If it pops up into a higher gear going uphill, which it often does, I let off on gas for an moment until it drops back, and gently ease the pressure back on.
My van gets the best mileage at 2000rpm, so I strive to stay in that range.
I've yet to need downshifting on the way down. But I'm pretty used to having crappy brakes. So by habit I'm always trying to avoid braking going down hill.

Yes..
It is interesting how Barometic Pressure, Altitude/Air density,Temperature & humidity creates a Large array of conditions that make the variable MPG on the "Rig".

 

[Cajunwolf]

About the same here until I hit the mountains. In December of last year, I went from Odessa, Tx, to Truth or Consequences, NM, back here to Houston and made 11.7 overall. I did 13.3 last week, running to San Antonio to see a cousin. I do carry a lot of weight, though. I've pulled all the emissions, 3-inch exhaust, and have a spare alt where the air pump used to be that runs to a charger made to keep my lithium batteries up while driving. I have panels on the roof, so this only helps when driving at night with the 6000 BTU A/C, and that's only if I need to.

 

[Willow4303]

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!
Willow

 

[Malamute]

Strong crosswinds will play a significant role in power required and fuel economy. The times ive had rigs get hot in windy conditions I tried to stop and park pointed directly into the wind to help it cool, either running at idle or shut off. Crosswinds require power to plow through and stay on the road in the direction you want to go and I believe affect the airflow through the radiator or engine compartment which will reduce cooling efficiency to some degree. A truck driving friend told me crosswinds affect his fuel mileage more that a headwind.

It sounds like your rig has a useful tow/haul mode that will probably negate most of the manual downshifting, though I dont know how well it does in extreme conditions like some of the western mountains have, like coming down the west side of the Bighorns in Wy into Lovell. 2 lane roads are not as gentle grades as Interstates also, nor do the have as much space to deal with faster than safe speeds should they happen, in other words they are less forgiving.

My vehicles are all old enough that using cruise when towing or just in hills without towing that I turn it off. The cruise on my vehicles seems to have an absolute obsession with not dropping ANY speed and is willing to SLAM it into passing gear and race the engine RPMs to avoid dropping ANY speed if possible. Thats hard on transmissions and my nerves. I dont really care if it drops some speed on hills, not to mentioned i can often maintain speed with gentle use of the accelerator pedal and be easy on my equipment where cruise wants to run the motor and trans as hard as possible in the insane quest to not lose 2 mph at any cost..

 

[Willow4303]

Strong crosswinds will play a significant role in power required and fuel economy. The times ive had rigs get hot in windy conditions I tried to stop and park pointed directly into the wind to help it cool, either running at idle or shut off. Crosswinds require power to plow through and stay on the road in the direction you want to go and I believe affect the airflow through the radiator or engine compartment which will reduce cooling efficiency to some degree. A truck driving friend told me crosswinds affect his fuel mileage more that a headwind.

It sounds like your rig has a useful tow/haul mode that will probably negate most of the manual downshifting, though I dont know how well it does in extreme conditions like some of the western mountains have, like coming down the west side of the Bighorns in Wy into Lovell. 2 lane roads are not as gentle grades as Interstates also, nor do the have as much space to deal with faster than safe speeds should they happen, in other words they are less forgiving.

My vehicles are all old enough that using cruise when towing or just in hills without towing that I turn it off. The cruise on my vehicles seems to have an absolute obsession with not dropping ANY speed and is willing to SLAM it into passing gear and race the engine RPMs to avoid dropping ANY speed if possible. Thats hard on transmissions and my nerves. I dont really care if it drops some speed on hills, not to mentioned i can often maintain speed with gentle use of the accelerator pedal and be easy on my equipment where cruise wants to run the motor and trans as hard as possible in the insane quest to not lose 2 mph at any cost..

Thank you for the information! I agree about cruise control, I rarely use it on any vehicle because even in later model vehicles it behaves exactly as you described. It makes sense that the wind was really throwing a wrench into the works, it was a difficult drive. I was getting shoved around nearly non-stop, even at lower speeds.

 

[eDJ_]

For those who would be operating in mountainous areas, would it make sense to add a transmission & engine oil cooler ?

Aluminum 6 row bolt on cooling radiator

 

[bullfrog !]

Interstate driving is generally a constant speed and they generally have longer grades compared to back roads and US Highways. Slowing down and then speeding up creates a lot of heat especially when going up and down hills and mountains. You’re better off not to travel or decrease drive times when traveling backroads or during inclement weather.

 

[Malamute]

My take away from experience on driving 2 lane highways a lot and towing is just to not get in a hurry and definitely dont force the issue of speed going up hills. If the motor is more comfortable going 45 up long grades, so be it, its much easier on it and you will likely not have as much overheating if not forcing it to go as fast as humanly possible. I hate wringing the guts out of my motors. If you slow down, turn on the flashers to let other drivers know youre going slower than traffic flow, dont be afraid to take breaks to let people pass if they stack up behind you, and on top of hills where theres pull-outs.

I prefer driving 2 lane roads much of the time, I find it more relaxing and theres more to see, I just re-calibrate my mental speed and dont get in a hurry.

Towing a large load of lumber and firewood in seriously steep grades in mountains Id often be going 25 mph up and 25 mph down the grades, its what the motor was comfortable doing. It didnt try to run away on the down grade and I wasnt cooking my brakes. A guy that was with me once sounded somewhat irritated asking if i was going to go 25 all the way down, to which of course I said "Yes, are we in a hurry?"

If you run right on the ragged edge of being able to brake to a safe speed, then having your brakes overheat, letting off them, then getting on them again to keep from going dangerously too fast, youre doing it wrong. If the brakes go out one of those times and youre already going too fast to make it without that breaking interval, youve got little or no leeway to stop. Ive been there, done that and ended up running the truck off the road into a dirt bank to stop it. Brake line broke. Since then ive never gone faster than I could emergency stop if the brakes failed, and usually drive down potentially interesting grades by downshifting and letting it engine brake at a comfortable speed thats not too hard on/over revving the motor.

Transmission coolers are good, and a temp gauge on the trans is good, if it gets hot, stop a few minutes with it running and preferably pointed into the breeze and wait for the temp to go down. It happens within a few minutes when ive done it.

Youre not carrying a heavy load, but if it was getting hot in the crosswinds, the result is similar.

 

[Overland One]

Just to add a point here to all of this great advice and tips from everyone about mountain driving, besides being killed or hurting someone else, overheating the brakes, even if you think you "got away with it again" can warp your rotors, especially if it is raining and they get cooled rapidly by road puddles after being really hot. Replacing rotors, even doing the work yourself like I do, is still not cheap. I just replaced both front calipers on my Dodge van and normally, I would have automatically replaced the rotors even though they looked good and had no grooves or run out. But, when I priced them, they wanted like $300+ each! I thought they would be about $50-$100 each like I was used to paying for my other vans and cars over the years. So, I just put them back on with the new calipers and new brake pads knowing I will need to replace them one day. My point here is, depending on what vehicle you have, if you overheat your brakes like this your chances of warping those rotors goes way up and replacing them could cost a lot.

 

[eDJ_]

Something I've not seen mentioned in this discussion is the replacement of older Ignition wires with quality replacement sets. It will make an impressive difference if this hasn't been done for several years. Those "spark plug wires" don't have wire in them, but instead have carbon impregnated fiber which will in time lose it's conductive ability. (car makers recommend 30,000 to 60,000 miles these days with OEM grade sets) The reason they don't have metal wire is so that it won't create interference with yours or other people's radios.

If you find a steep grade or a hill somewhere and take your rig about half way up and stop and then try to accelerate from being stopped and you hear your engine cough, backfire or stumble........you may be ready to replace the ignition wire set. A new set of ignition wires make a big difference in your rig's performance and even gas mileage.......especially in mountain driving.

 

[Malamute]

Something I've not seen mentioned in this discussion is the replacement of older Ignition wires with quality replacement sets. It will make an impressive difference if this hasn't been done for several years. Those "spark plug wires" don't have wire in them, but instead have carbon impregnated fiber which will in time lose it's conductive ability. (car makers recommend 30,000 to 60,000 miles these days with OEM grade sets) The reason they don't have metal wire is so that it won't create interference with yours or other people's radios.

If you find a steep grade or a hill somewhere and take your rig about half way up and stop and then try to accelerate from being stopped and you hear your engine cough, backfire or stumble........you may be ready to replace the ignition wire set. A new set of ignition wires make a big difference in your rig's performance and even gas mileage.......especially in mountain driving.

View attachment 33884

...and boys and girls, remember to only remove one spark plug wire and replace it at a time. Simply pulling all the old ones off then trying to figure out where each one actually goes so its in the correct firing order can be trying to ones patience and blood pressure.

 

[wayne49]

Do Not Stop in the middle of a steep climb. Keep moving. Keeping an object in motion requires less energy, than what is needed to get a stationary object moving.

Another thing is, if your engine temp is running hot during the climb, do not stop at the summit to try to cool it off. The engine will no longer be cooled by moving air and will continue to get very, very hot. Continue over and down in a lower gear, for engine braking, and the temp will drop quickly to normal.

 

[tx2sturgis]

Side winds and cross winds will cause underhood temps to rise noticeably, so that explains the felt warmth in the floor and console areas, as long as all of the gauges were in the normal range, you should be good to go. You may or may not be aware of the engine fan engaging, but trust me, it was doing exactly that, and that very powerful and noisy fan will blow all of that heated air (from the radiator) thru the engine compartment and where do you think it escapes? Right under your feet, under the floor and engine dog house.

The E450 SuperDuty already has an aux heavy duty transmission cooler, so there is no need to add this, but I would suggest adding an auxiliary OBD monitor, I use the Scan Gauge units, but there are many options, and some of them are wireless and send the information to your smartphone. These units will display data from each and every sensor in your drivetrain: charging voltage, oil temp, coolant temp, transmission temp, catalytic converter temp, current horsepower, average mpg, ambient air temp, intake air temp, current mpg, engine rpm, torque converter slip, error codes, etc etc etc.

With one of these installed, you dont have to guess what is going on, you will KNOW if your transmission is overheating, your coolant is too hot, or anything else that is not 'normal' that a factory sensor is monitoring.

 

[dreamrunnerjt]

...and boys and girls, remember to only remove one spark plug wire and replace it at a time. Simply pulling all the old ones off then trying to figure out where each one actually goes so its in the correct firing order can be trying to ones patience and blood pressure.

And remember to use the shortest wire to the furthest away connection that it will reach first. That way you don’t wind up with the last wire not fitting. I was 16 when my BF taught me that.

 

[Overland One]

And remember to use the shortest wire to the furthest away connection that it will reach first. That way you don’t wind up with the last wire not fitting. I was 16 when my BF taught me that.

That's a good tip.

 

[Willow4303]

Hello to all! I just got back from the trip through Wyoming and a small portion of South Dakota. I put the rig in towing mode, and used the Scan Gauge (came with my rig from previous owner) that @tx2sturgis mentioned, and everything went very well; transmission etc. remained in happy range for the duration!

 

[hugemoth]

We have some steep grades here in Oregon but since my camper is on a manual transmission Toyota pickup it's not a problem. Just use low gear and apply the brakes briefly now and then.