Saturday, September 30, 2023


RVs that use the least fuel – First in a 3-part series

It’s no secret that we’re all frustrated by the price of fuel. One of the common threads in many social conversations is if people are actually planning to curtail their travels for the season because of the cost of a gallon of fuel.

In fact, many of you responded to a reader poll stating that you would make changes to your plans based on the price of fuel.

But we also know, based on the popularity of these daily RV reviews, that a lot of you are shopping for new RVs. So I thought I’d look at a few RVs that offer the lowest cost to operate from the standpoint of fuel economy. 

What affects fuel economy

There are a lot of things that affect how much fuel you use to travel a mile. While a common misconception is the number of cylinders an engine has, this number alone isn’t going to affect mileage much. 

Take, for example, a Ford F-150 with the EcoBoost® six-cylinder engine. That engine sports 430 horsepower and 570 lb.-ft. of torque. That’s a lot of gusto. In fact, depending on which version of this engine is chosen, that’s more torque than the company’s new 7.3-liter gasoline V8—which is a huge V8. That V8 offers the same 430 horsepower but “only” 475 lb.-ft. of torque. 

So it’s not just cylinders, but a lot of factors. 

The air that you breathe

Essentially, an engine is nothing more than an air pump. The more air it can pump, the more power it has. This is a huge oversimplification, by the way. 

But another thing that radically affects fuel efficiency is how much power it takes to shove something through the air. If you look at the modern passenger car there is a legitimate complaint that “they all look alike.” There’s a reason for this. 

Cars are heavily regulated and one of the aspects of that regulation is fuel economy. The government has a fuel economy standard that carmakers need to achieve, so the cars are designed to use as little fuel as possible. Since shoving a car through the air is subject to the same dynamics as an RV, it makes sense that changing the shape of the RV to move more efficiently through the air would reduce the amount of fuel it takes to accomplish this. 

This is something that was recently studied by Airstream. It found that the shape of its trailers was less resistant to the forces of the wind than the typical square box that is your average travel trailer. 

Better mileage RVs

So, as promised, I’m going to look at RVs that are the most judicious with a gallon of fuel. I’m going to milk this, er, stretch this over several days. Today we’re going to start with motorized RVs. 

Essentially you’re going to see that there’s a very common theme here. Shoving a large box through the air is the least efficient way to move a rig, so the RV that takes the least amount of fuel to move is likely the one with a diesel engine, of course. 

But there are literally no Class A or Class C RVs on this list. Why? They’re gigantic boxes that are about as aerodynamic as your home. Maybe less so. 

These big square vehicles then add insult to injury by putting all sorts of things on the roof such as air conditioners, vent covers, satellite receivers and more. If your only factor in making a decision when buying an RV is fuel economy, then these are the ones to distance yourself from. 

Don’t feel badly. Travel trailers and fifth wheels, too, suffer the same fate. Well, except for the ones that we’ll mention tomorrow. 

The mileage maker

But the most efficient Class B RV I have reviewed, to my knowledge, is one that’s a favorite for a lot of reasons. That would be the Embassy RV Traveler, if you specifically get one based on the Mercedes-Benz Sprinter chassis. 

The reason for this is that you start with the already-efficient Mercedes-Benz 3.0-liter turbocharged diesel engine, and then don’t make as many profile-changing alterations to that shape. 

So the air conditioner in the Embassy RV Traveler is a different sort of unit that’s based loosely on the Toyota Prius AC system. It’s far more efficient but is also infinitely repairable, unlike all those Coleman units that are so popular. It’s also lower in profile—and that’s where you see the benefit. 

You can also get an Embassy RV in a Ram ProMaster® wrapper; it is a gasoline V6 engine. While there are no federal requirements to provide fuel mileage ratings for larger-capacity trucks, it seems they’re getting about 17 miles per gallon on the highway. 

What I really like about this company is the innovative approach they’ve taken to the whole build process. Every aspect of the design and construction was looked at to optimize that process or system. 

Another leader

The very spacious seating/sleeping area in the VANaholic

Another really solid Class B option is the VANaholic build. You can bring just about any van to Vanaholic and they’ll customize an interior based on their pieces to fit what you need. Not only does the company tailor their build to the van, but you could build one without a rooftop air conditioning system. That would eliminate the drag of one of those systems. 

Better yet, VANaholic uses an aluminum building system that provides a significantly lighter van than is typical with almost every other build. Yet this build methodology also results in a much stronger interior structure than wood would provide. 

While the assumption might be that reducing weight would increase fuel economy, this is less true in the circumstances where we drive our RVs. 

If our RVs were mostly confined to traffic and city life, then weight would be a bigger factor in their mileage. But since much of what we do is drive on the open road, it’s aerodynamics more than anything that can affect things. 

Still, there’s no harm in things being both lighter and stronger, and VANaholic doesn’t use any wood in their construction. Lighter and stronger is better, in case you’re keeping score. 

Another benefit of the whole bring-your-own-van model is the fact that you might be able to still find an older Mercedes-Benz Sprinter van with the five-cylinder diesel engine. Those were also marketed under the Dodge and Freightliner brands. 

Those things were really good at squeezing a mile from a gallon of diesel fuel and, bonus, they’re just simpler so more easily maintained. And, bigger bonus, no DEF.

Honorable mention

These smaller diesel rigs are actually pretty darned efficient, so you won’t see a huge difference in fuel mileage even with the rooftop air conditioners. 

Winnebago Travato

So with that in mind, perhaps something more mainstream might be to your liking. I am quite a fan of several of the Class B RVs in the Winnebago family. The Winnebago Travato 59RL is based on the Ram ProMaster® chassis. So you’ll have a gasoline engine, but this isn’t an inefficient package as far as motorhomes go. 

It’s also a rare example of a Class B that actually has a usable bathroom—and there’s a lot to be said for that. To be fair, the Embassy Traveler has a similar floor plan.

Winnebago Revel

If you do choose to go diesel, then perhaps a Winnebago Revel 44E might suit you. Winnebago has done an unusual thing with the bed in the back by adding flares to where the rear-most side windows might otherwise be— so you get a bit of width. This isn’t significant enough to make a noticeable difference in the fuel economy of this rig, though. 

Since I’ve written that many RV companies just use the brochures from their competition as design inspiration, you could say the Jayco Terrain is a perfect example of that kind of thinking. Not that that’s necessarily a bad thing, but something to consider. 

In summary

We’ve got lots more options to look at in the mileage-maker department over the next couple of days, culminating with a look at the future and a look at the past. 


I would love to read your comments and suggestions over on our new forums, where you can weigh in and start or join a discussion about all things RV. Here’s a link to my RV Reviews Forum.

Tony comes to having worked at an RV dealership and been a lifelong RV enthusiast. He also has written the syndicated Curbside column about cars. You can find his writing here and at StressLessCamping where he also has a podcast about the RV life with his wife.

These RV reviews are written based on information provided by the manufacturers along with our writer’s own research. We receive no money or other financial benefits from these reviews. They are intended only as a brief overview of the vehicle, not a comprehensive critique, which would require a thorough inspection and/or test drive.

Got an RV we need to look at? Contact us today and let us know in the form below – thank you!


Tony Barthel has been a life-long RV enthusiast and travels part-time with his wife where they also produce a podcast, write about RVs and love the RV lifestyle.


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Tom S
1 year ago

I don’t understand why rv manufacturers don’t use honeycomb materials like Aircraft makers do. Light and strong. Probably costly though.

Over about 38 years our rv’s have been:
1976 Winnebago 26.5 ft class c 350 that got 7.7mpg
1979 Chev 3/4 ton 4×4 w/350 and 9 1/2 ft cab over 8mpg
1984 Southwind 28 ft 454 8.3mpg
1997 Safari 35 ft 3126 CAT diesel 8.8mpg
Overall the Safari is the most fun to drive and use and have had the fewest problems. It’s also the only one we have never run out of power with.

Tom S
1 year ago
Reply to  Tom S

I forgot to mention I pull a Honda Civic that gets 40mpg with the Safari. Only towed we ever had.

Joel Stewart
1 year ago

Ford 2000 7.3 diesel 4r100 trans 3.73 gears no trailer 20-21 mph, w/ trailer 17-18mpg… Trailer weight 3500lbs,so truck does not struggle, at all anywhere…

1 year ago
Reply to  Joel Stewart

Amazing how badly the emissions stuff hammers the mileage. My 6.7L dodge eekes just over 20mpg with no trailer unless the regen kicks in. 17-18 then. With 10k 5er I’m in the 12-14 mpg range (no regen). Still better than my old 5.4 liter f150 that was in the same range as the new USPS trucks pulling our TT. 😉

Michael Galvin, PhD
1 year ago

The RV Reviews should include MPG.

Donald N Wright
1 year ago

tony, I have been unsuccessful at contacting the Engineer who did the Airstream Trailer tests. My main complaint is those big box A/C’s on the roof. However, has anyone wind tunnel tested various spoilers or wings to install on TV to guide the wind over or around the trailer? I wish there was a “Sports Car Graphic” test information available.

1 year ago

Hmmm We have averaged 14.9mpg in our 2020 Thor Quantum Sprinter 21,000 miles so far…

captain gort
1 year ago

I have a Sequoia 5.7 2WD towing a 5500# Rockwood 2109s MiniLite TT. Without the trailer, I’ve seen the Sequoia get better than 20mpg on straight, flat highway with no headwind at 65mph. But overall, it averages about 17-19. This gets cut almost exactly in half when the trailer is being towed….and worse on long, steep mountain highways. And yes, the fancy new twin turbo V6 & hybrid rigs may do much better when NOT towing…but that all changes when towing a big load up a long incline. Work is work…and work takes energy. And that means BTUs of fuel consumed. Its physics and chemistry. No way out! These B+ vans look intriguing…but they are narrow and cramped inside compared to my TT. And good Lord…they are exorbitantly priced! And you have to break camp to tour or run errands…or tow a toad but there does your gas mileage and you are still cramped into a narrow tunnel.
There is no magic bullet. And certainly NOT electric.

John snell
1 year ago
Reply to  captain gort

You are correct . The larger the engine the less work to haul the RV.

1 year ago

I’m curious what you think about (and am hoping you make an honorable mention) about the fuel economy of the truck top camper. I have a rather large one that sits a top a Ford F-350 diesel. Campers are left out of RV discussions all too often.

RV Staff
1 year ago
Reply to  Laurie

Sorry we don’t have a lot on truck campers, Laurie. In a couple of polls we’ve run, those who have truck campers made up less than 2% of our readers. It might be interesting to run that poll again. Have a great day. 😀 –Diane

1 year ago
Reply to  RV Staff

I recently downsized from a 42 ft 5er. So much easier to get campsites, with this camper. We can park it anywhere. It might be interesting to see if the percentage has gone up and how many others have done the same. I have seen a lot more campers out there on the road. Great day to you as well 🙂

1 year ago
Reply to  RV Staff

WOW! I finally made at least the 2% club! Now, what percent of donating readers have a ‘turtle’ truck/camper setup?

RV Staff
1 year ago
Reply to  Bill

I don’t think we’ve done a poll breaking it down that far, Bill. 😉 Have a great day. 😀 –Diane

colin grant
1 year ago

I have a 2006 Sprinter 2500 which was the last year of the 5 cylinder diesel. I average 22 mpg overall with a light foot on the pedal. My Pleasure Way TS weighs 7500 lbs. with a full water tank and me in the drivers seat. It is a 3/4 ton chassis with single rear wheels which has a 2 mpg benefit compared to dual wheel models. Single rear wheel vans also qualify for your car policy with AAA for no extra charge. If you are always in a hurry and drive at 65+ mph you’ll be at 20 mpg or less. I would never have bought an RV if I couldn’t get an efficient one as I live in Canada home of expensive gas. Metric fuel economy is 10.3 L. per 100 km which equals 22 mpg US gallons.

1 year ago

I hope you have the B+ category in mind for part 2. Getting 15 mpg in mine, with a truckload more storage, functionality, and livability than a B. And lower cost from the start.

1 year ago

As I begin to comment, I feel a long comment coming on. I’ll keep it as short as I can even though that might result in more questions. A basic principle of life is that there are facts and there is opinion. Two people can argue opinions but no one gets to argue with fact. A second principle is that form should follow function. How do these principles play? If the ‘thing’ doesn’t do what you want it to do, it doesn’t matter how little it costs. Similarly, the closer you get to the capability of the ‘thing’, the more you are going to pay. The facts I use to support these opinions are in a spreadsheet that I have kept for the total cost of operation for my past five vehicles.Total cost of operation includes the capital cost – purchase plus improvements minus sale – plus insurance, maintenance, repair, and consumables – the big one is fuel. As a result of keeping records (facts) I can tell you the per mile total cost of operation.

(out of space – I’ll continue in a second comment)

1 year ago
Reply to  Warmonk

What do I conclude (opinion derived from facts)? 1) new beats used 2) diesel beats gas 3) don’t exceed 75% of your GCVWR.

What else? I drive my MINI Cooper S like the thoroughbred that it is. I drive my Colorado diesel like the Clydesdale that it is.

The MINI is a 4-cylinder turbo premium gas AWD and gets 40 mpg on the highway. It loves snow, ice, wind, and winding roads. It’s fun. The Colorado is a 4-cylinder turbo diesel 4×4 and gets 35 mpg regardless of the load. It doesn’t like ice but goes up or down any hill and over the roughest roads as if everything were flat and paved. It’s practical. They have virtually identical per mile total costs of ownership.

Conclusions: Match the vehicle to the task. Match your driving to the vehicle. Accept that fuel is a small part of the total cost. And expect to pay for what you do.

Jesse Crouse
1 year ago
Reply to  Warmonk

Right on Warmonk. that’s why our 2006 Tiffin Phaeton 40QSH with a CAT C-7 fits our bill to a tee for why we have it. Not everyone’s cup of tee.

1 year ago
Reply to  Jesse Crouse

We have a Cummins 340 in our MH and have no issues with it. It’s all about the HP/torque to weight ratio. The 340 is one of the best for fuel consumption

Bob p
1 year ago

I hope by the time you get to day 3 you won’t be talking about RVs that will take the better part of a week to get to you destination because their batteries won’t get them much more than a hundred miles before spending several hours in Starbucks awaiting a recharge that will take you another 108 miles down the road. The next 20 years EVs will have a significant place in transportation, but for the time being they are basically commuter cars.

1 year ago
Reply to  Bob p

If you use campgrounds much you’ll notice many Teslas towing teardrop or iPods. Range anxiety is in the mind of the non-electric vehicle owner I think.

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