Mountain MPG

[wermlr75]

We'll be driving through some mountains (Arizona, New Mexico, etc) for the first time and I'm hoping for some guidance on how they affect MPG. The worst I've gotten so far was 8.5 going into a headwind in some hilly country.

 

[kenandterry]

We'll be driving through some mountains (Arizona, New Mexico, etc) for the first time and I'm hoping for some guidance on how they affect MPG. The worst I've gotten so far was 8.5 going into a headwind in some hilly country.

No one can give you an exact answer. What speeds do you hope to drive at? How heavy is your rig? How steep are the roads you’ll travel?

Prepare for 5 MPG……maybe worse, maybe better. Nobody expects great gas mileage moving their over-the-road home.

 

[Mr. Dan]

For those who can't see the member's signature, it says
2018 F250 4x4 Diesel
2023 Flagstaff 8529CSB (now called a 372RL)

 

[Reverse_snowbird]

We'll be driving through some mountains (Arizona, New Mexico, etc) for the first time and I'm hoping for some guidance on how they affect MPG. The worst I've gotten so far was 8.5 going into a headwind in some hilly country.

Your mileage will go down as you climb the mountains. Your mileage will increase as you go down the other side, but your brakes will be tested, so make certain you learn to downshift.
Gas/diesel stations in some areas will be difficult to find, so fill up when half full.

Safe travels.

 

[Bob K4TAX]

Your mileage will go down as you climb the mountains. Your mileage will increase as you go down the other side, but your brakes will be tested, so make certain you learn to downshift.
Gas/diesel stations in some areas will be difficult to find, so fill up when half full.

Safe travels.

You mileage depends largely on the right foot pressure. In other words, less is best. You just have to be the judge, knowing your truck, your trailer and the road conditions relating to inclines and declines.

An exhaust brake system sure saves on brakes on both the truck and trailer on those long down grades. If the truck is equipped with a tow package, engage the tow mode and let the computer handle the shifting.

Bob

 

[DbleDutch]

We'll be driving through some mountains (Arizona, New Mexico, etc) for the first time and I'm hoping for some guidance on how they affect MPG. The worst I've gotten so far was 8.5 going into a headwind in some hilly country.

We have moved our RV rigs in the 12,500 lb range from the desert 1k elevation to the mountains 7-8k elevation regularly for years. Average 7-8 mpg for our gassers. Friends with their diesels get slightly better hauling, but we do better when not hauling. Use all the tools your tow vehicle has to control climbs and down hills.

Enjoy your travels and watch weather for the high elevations. Snow has started to fly.

 

[DougW9876]

We went from Las Cruces over the hill to Alamogordo, Roswell, and on into Amarillo on a trip from AZ to Western NY with a 2014 F350 diesel pulling a 12,000lb fiver and that tank of fuel was the best of the whole trip. It was long ago enough that I don’t remember the actual mileage numbers but I do know I was surprised at the increase over the mountains. I suspect it all had to do with winds and the lower speeds driving over the mountains but never really studied it to hard.

 

[jjscsix]

I can’t speak for a tow vehicle, but I have ridden many, many thousands of miles in the Rocky Mountains on motorcycles. I get 10% + better mileage in the mountains than i do in normal riding, I think for two reasons. One is that my average speed is a lot lower even when I’m on flat land, and the downhill makes up for the uphill.

Pulling a trailer certainly could be a lot different due to the load.

 

[Chuck_S]

Air resistance remains the biggest user of fuel once the rig is rolling. Air resistance is also exponential meaning it's twice at 70mph than it was at 50mph (whatever that was). No, you won't use half the fuel at 50 than 70 but it will be noticeably better.

If your main concern is fuel just slow down.

-- Chuck

 

[Bob K4TAX]

Air resistance remains the biggest user of fuel once the rig is rolling. Air resistance is also exponential meaning it's twice at 70mph than it was at 50mph (whatever that was). No, you won't use half the fuel at 50 than 70 but it will be noticeably better.

If your main concern is fuel just slow down.

-- Chuck

As I wrote earlier, "Your mileage depends largely on the right foot pressure." The more one presses it down the lower the MPG.

Bob

 

[ppine]

Right foot pressure is part of the story. Staying in the power band for your engine and controlling the speed and gears is important. So is anticipating the crest of a hill or mountain range. I want to be going under the speed limit at the top.

Pulling in the mountains is when diesels show their total superiority. Mileage, performance and longevity.

 

[NMWildcat]

Don't be afraid of the mountains out west!! Just go slow, watch your temps, and when going downhill, go slower.

For interstate mountain driving, your mileage will likely go down a bit, but on the slower 2 lane roads, it may actually go up.

Trick is to let your truck do it's thing as far as gear selection, it is smarter than you. On very steep uphills, I will reduce my speed and lock out the higher gears. This is mainly for temp control during hot weather (lower gear to keep the rpms up and slower speed to keep the rpms in range).

Going downhill, start off slow and let the transmission gearing and engine brake work. Most downhills the only time I tap the brakes is to keep rpms in range. Usually never even touch the brake.

As far as worrying about mpg, stop it! Just try to never go below half a tank out here and plan your fill up locations.

 

[ppine]

Easy to tell people that haul in the mountains. It just takes some practice. Some passengers get freaked out if they are from flat country. They can be a nuisance if they are very vocal. Practice makes perfect. Stay on the interstates at first, then US Highways. Check with local people about secondary roads.

 

[D W]

Definitely going to affect MPG in New Mexico, especially around Santa Fe. That place is well over 1 mile above sea level.

 

[wermlr75]

Thanks all for the advice. I'll be going slower (55-60, much to my DW's chagrin) and will be using the Tow-Haul feature. And, annoying as it is, stopping to fuel up a little more often until I get a feel for it.

 

[Reverse_snowbird]

Another thing.....

If you've never driven the mountains in the west towing a trailer, be aware that crosswinds can be dangerous. They aren't predictable and when they hit the trailer broadside, it's easy to lose control. Know where your brake controller is and how to use it.

 

[MR.M]

We'll be driving through some mountains (Arizona, New Mexico, etc) for the first time and I'm hoping for some guidance on how they affect MPG. The worst I've gotten so far was 8.5 going into a headwind in some hilly country.

The best mileage i have ever gotten towing is when i'm in the mountains out west . it's either because each up has an Almost equal down or more and the fact that the engine computer is leaning out the fuel for elevation though you lose power along with that . down in the flat lands 7.5 to 8.5 mountains 9.5 to 10.5 so go figure .

 

[Corn-Belt]

Thanks all for the advice. I'll be going slower (55-60, much to my DW's chagrin) and will be using the Tow-Haul feature. And, annoying as it is, stopping to fuel up a little more often until I get a feel for it.

I just returned from a 4000 mile trip from the Midwest to Idaho and back. Worst mileage was Day 1 traveling West from my home in MN against a headwind and last day driving east and north through IA (less than 9 mpg). My best milage was driving east through WY across the plateaus at 6000 feet elevation- was at 20 mpg for most of a tank. Averaged 11-12 mpg over the whole trip. My new theory is that altitude has nearly as much impact on wind resistance as the wind direction and speed itself. I also drive slow (58 mph) and believe that helps mpg a lot as well as the safety and comfort level with my particular vehicle combination.

 

[Chuck_S]

The "Miles to Empty" display can be set to Towing on my Expedition so I assume your truck has the same ability. The drop after 50 miles seems very fast. Plan your fuel stops. Don't be fussy about fuel brand, the engine doesn't care. And since BP changed their credit cart to VISA I can get gas anywhere and it all shows up on the BP statement which my wife pays!

-- Chuck

 

[Sunseeker16]

Feed it when its hungry and take your time both up and down hill. Brakes can get hot just use the tools you have built into the vheicle and youre trip will go well.