Choosing a Diesel vs Gas Motorhome: Getting Where You’re Going


Whether you’re buying your first motorhome or replacing an old one, choosing between a diesel and a gas motorhome is quite a decision to make. It’s the type of thing you have to compare the pros and cons of and write on a whiteboard or a piece of paper to see what actually fits your needs. So that’s exactly what I did. 

What are the pros and cons of diesel and gas motorhomes? Diesel motorhomes are built for high torque performance- full-timers, massive RVs, boondocking. They are more expensive to buy and maintain but have more mileage. Gas motorhomes are built for leisurely rides and vacationers and are more affordable upfront, easily serviceable, but have less mileage.

By the end of this article, you’ll get to know the different pros and cons of diesel and gas-based motorhomes, the people who’d best use the type of motorhomes, and some RV models that use these engines. The ultimate goal of this article is to help you decide on which RV motorhome would be best suited for you. Lastly, an insight into all-electric motorhomes and why these would be a great option in the future. 

Diesel Motorhomes

Image Source: “Millennium H3-45 Quad Slide #1957” by MillenniumLuxuryCoaches is licensed under CC BY-NC-SA 2.0 

Diesel motorhome engines work by compressing only the air. This increases the air temperature inside the cylinder to such a high degree that atomized diesel fuel injected into the combustion chamber ignites spontaneously, meaning the sparker is used only for the first ignition then goes on from there, unlike gas motorhome engines where the sparker constantly works. With the fuel being injected into the air just before combustion, this creates a heterogeneous air-fuel mixture. 

The torque a diesel engine produces is controlled by manipulating the air-fuel ratio; instead of throttling the intake air as do gas engines, the diesel engine relies on altering the amount of fuel that is injected, and the air-fuel ratio is usually high. This control of fuel uptake compared to air uptake creates better torque and more reliable braking-  this is why diesel engines handle weight very well.

Who This is For

Diesel based motorhomes are basically for people looking to live in an RV for long periods of time because of the great mileage it offers. These would include full-timers, retirees, and frequent RV vacationers. Because of the relatively better floor plans and that you could furnish it with a lot of things without worrying about the weight, it could be a good choice for glampers. Although don’t get me wrong, gas motorhomes could also be fancy as hell. It’s just that diesel motorhomes could carry more weight for those extras. 

Because of the great torque provided by the mechanism of the engine, diesel motorhomes are recommended for boondockers because of the driving terrain- relatively steep ascents and descents, rocky mountain roads, and tight spots. Some diesel models are made more compact for easier maneuvering in tight spaces. Good torque and more compact is definitely made for the mountains.

With that said, the ability of the engine to handle weight better makes diesel engines a great option for really massive RVs. Although usually, huge spacious RVs are gas-based because they’re primarily made for wide-open flat terrain, a diesel on a huge class A would not be a bad idea.

Pros 

Image Source: “2010 Millennium XLII, #9399 – SOLD” by MillenniumLuxuryCoaches is licensed under CC BY-NC-SA 2.0 

There are a lot of pros of getting a diesel-based motorhome, first is the benefit of the engine mechanism. Producing a superior low-end torque is a great feature that is important when you want to climb mountains, and tow heavy stuff. This would be irrelevant if you plan on driving on open and relatively flat terrain. It is more fuel-efficient though and has a better fuel economy, but that gets offset by the price and availability of diesel, as well as the price of the unit since diesel motorhomes usually cost more than gas-based units.

Since  the engine is situated at the back of the van, one pro for diesel engines is that it is quiet to drive. You could have a decent conversation while driving these babies. It may be louder from the outside and at the back, having distance from the engine makes it more pleasant to drive. It also gives a smoother ride owing to better weight handling. 

Speaking of engine handling, it has relatively better and safer braking. Unlike gasoline engines, diesel engines vary fuel flow to control power, rather than throttling air intake and maintaining a constant fuel ratio as gasoline engines do. Since they do not maintain a throttle vacuum, they could control braking better. In a sense, engine brakes work way better in diesel-based units compared to gas ones. 

The next thing you want to look at is the built and the interiors. Diesel motorhomes are built to have better floor plans because of where the engine is. It usually has nicer components and is equipped with luxury fixtures. Well, it could afford to because it can carry the weight of those luxury extras. Hello, glampers, this one’s for you. 

Another great pro for diesel motorhomes is how they’re built. Although finding a diesel mechanic and shop that maintains diesel engines is more of a challenge than gas engine shops, these engines would give you a whole lot of mileage before they present any problem. This is why they say it saves you money in the long run, which is true. Also, it tends to retain its value longer than their gas counterparts. This gives them a higher appraised value later on when you’re looking to resell them. 

Cons

The big con that might affect your decision is that diesel motorhomes are more expensive upfront. This is true when buying either a new or used one because of how it’s built. Diesel motorhomes depreciate more slowly than gas motorhomes do. 

As I’ve said earlier, diesel motorhomes can be built so massively as their engines can handle the weight. Bigger isn’t necessarily better as it’s harder to maneuver these big babies in tight spaces like in gas station aisles. But again, this con is due to the size of the motorhome and not the engine.

Speaking of gas stations, diesel is a little pricier than gas. Having said that, the overall cost is balanced out by the better fuel economy of diesel engines. The only thing that may be a factor is the availability of diesel as not all gas stations have diesel. This con isn’t really a big bummer, all it needs is a little more planning, searching available diesel stations in advance, and probably taking some extra with you just in case. 

So, if fuel availability does not bother you, this one con might. Diesel engines need diesel exhaust fluid (DEF) for exhaust emissions. There is an increase in states requiring this for diesel-based vehicles. The problem here is that DEF can sometimes be hard to locate, and it isn’t cheap to buy and install. Basically, the money you save because of great fuel economy is offset by the cost of diesel and DEF. 

Also, although you do save money in less frequent engine maintenance, maintaining diesel engines usually costs more than gas engine maintenance and they take more time in the shop per visit.

RV Models Using this Fuel

Image Source: dieselrvrentals.com

A few examples of RVs using this fuel are the Forza at $269,000 and the Horizon at $435,000. Both are Class A RVs from Winnebago. The Revel is sold at $175,000, the Boldt at $202,000, and the Era at $174,000 are all Class B Winnebagos. The brand also has Class C RVs- the Fuse at $129,000, the Porto at $126,000, and the Vita at $126,000.

While doing a little research on the diesel motorhomes by Winnebago, it was easy to see that their diesel motorhomes generally are more compact than their gas units. Maybe they are made for tighter than usual spaces, like the boondocks, I thought. However, this is not true for all brands. Some diesel motorhomes are still made to be large and in charge.

Gas Motorhomes

As per Wikipedia search, the gas engine works starting with a spark. This ignition-type engine uses a spark plug to ignite an air-fuel mixture with each stroke. Compared to a diesel engine, gas engines control airflow rather than fuel uptake. Due to the mechanism of throttling the air or restricting air for an engine brake, gas engines have relatively less reliable braking compared to diesel engines. 

One more thing about gas is that because of how it’s chemically made, it’s a lot faster to go from 0 to 60 km/h in a gas based engine and maintain that acceleration throughout the drive. These things may be important in flat terrain as acceleration is easier to achieve with gas engines, but will less likely be relevant when the RV goes uphill or downhill. It again boils down to what your RV trip itineraries are going to be like. 

Who This is For

Gas motorhomes are more affordable than their diesel counterparts. That said, it’s the main point for determining who these vehicles are for. They’re for relatively transient users of RVs like vacationers. It’s a practical choice to spend less on an RV that you’ll be using only a few times a year. And, no, it does not compromise the amenities available since a lot of gas motorhomes are also made pretty fancy.

Families going on RV trips are also great users of gas-based motorhomes. Layouts on these RVs are more family-friendly as they usually have bunk beds and are more spacious than their diesel counterparts. Speaking of being spacious, gas motorhomes are made for wide, flat, and easy terrain. It’s easy to understand why we’d often see massive gas motorhome units in the market.

Another perfect match for gas-based RVs are people visiting flat places with high altitude. This may be an odd entry but it has truth to it, well, because science! Diesel engines hugely rely on the first spark to run the spontaneous combustion and because diesel is relatively thicker, the added effect of a high altitude makes it harder to start the vehicle, and this might cause you problems later on. This would rarely happen with gas-based engines.

Pros 

A huge pro for gas-based motorhomes is affordability. Gas motorhomes are more affordable upfront. They usually cost around 30% less than their diesel counterparts! Also, gas is a more affordable and accessible at the same time. Some gas stations do not have diesel so this may be a big factor come decision time. 

Service shops and gas stations are more common, making gas-based motorhomes a practical choice. The accessibility to gas service shops for gas motorhomes are relatively less expensive to maintain. 

Due to an inferior torque, some gas motorhomes are usually made smaller than diesel motorhomes. This may be viewed as a pro as getting into tight spaces would be a piece of cake. This is especially useful in gas stations and campsites. Again, this pro rides on the size of the RV, and not because it is a gas or diesel-based one. 

One more thing to note about gas engines is that they tend to be more resistant to cold and perform better at high altitudes. This could be extremely important depending on your location or travel destination. So if you’re thinking of an Alaska trip that focuses only on parking in campsites and going on trails by foot, a gas motorhome is the way to go. 

Another thing about gas motorhomes is their layout. As I’ve said earlier, gas motorhomes have a very family-friendly layout and are also made spacious and lux when made for flat terrain. Having said that, it’s easily understood that these motorhomes have a lot more storage space than the diesel ones. This is a very big pro when traveling with kids or pets, or even on your own- a place for everything.

Cons

Just like diesel motorhomes, gas motorhomes have their share of cons, too. To start off, gas engines have inferior torque, meaning, they have less capacity to handle the weight and have weaker towing power. Although this would be less of a con if you would be driving in relatively flat terrain. In that case, gas is your best friend. 

Gas motorhomes, when driven, usually offer less comfort than diesel-based motorhomes. One of the things that might be a bother is that it’s a little noisy when driving since the engine is in front. One thing more about sound, the generator usually sits below bed at the back of the RV. Now, this might either hum you to sleep or you might not get any shut-eye at all.

Gas motorhomes usually present with more nitty-gritty flaws within just a few weeks of driving them. Although service shops are easily available almost anywhere, gas motorhomes do undergo frequent maintenance. Frequent maintenance means more expenses in the long run. Although remember, the unit was more affordable when you bought it, so it balances out. 

Another factor to consider is longevity. Gas motorhome engines do not last long as diesel-based motorhomes do. They do have more time in the shop as to frequency and they depreciate faster. This would not be much of a con if you plan on taking the RV for occasional holidays throughout the year. This would be a factor if you plan to resell after that stint as gas motorhomes do not hold their value for long.

Although there are many fancy Class A gas RVs, there aren’t a lot of them having super luxury fixtures that you could expect in diesel motorhomes. Not that they aren’t well made on their own, diesel engines just could handle the weight luxury items bear that gas engines could not. Not to mention, having to pay top dollar for these amenities in diesel motorhomes. Gas motorhomes give you the value for your money, that’s for sure. 

The last thing I want to mention is the gas engine’s mechanism for braking. By consulting Wikipedia, we would know that the term “engine braking” refers to the braking effect that occurs in gasoline engines when the accelerator pedal is released. 

This causes fuel injection to cease and the throttle valve to close almost completely, greatly restricting forced airflow. The latter of which causes a strong manifold vacuum for which the cylinders have to work against—sapping much of the potential energy out of the system over time, and producing the majority of the engine-braking effect.

This type of braking is a relatively less reliable way of braking as it relies on the vacuum and control of air, which is more difficult to achieve rather than the diesel engine’s mechanism of controlling fuel intake. This is also why with added weight, diesel engines are more reliable. 

Although this is not to say that gas engine brakes do not work, they perfectly do. Most cars in the US use gas-based engines and they work perfectly fine. It’s just the heavy RV weight that becomes a factor here. Heavyweight vehicles are better handled by diesel engines.

RV models using this fuel

Image Source: vistarv.com

A few Class A models from Winnebago include the famous Vista at $142,000, the Adventurer at $170,000, the Sunstar at $142,000, and the Intent at $123,000. They only have two Class B’s at Winnebago- the Travato at $119,000, and the Solis at $102,000. The Winnebago Class C’s include the popular Minnie Winnie at $106,000, the Spirit at $105,000, and the Outlook at a mere $93,000 which already can sleep 5!

On a side note, for Winnebago, usually, gas motorhomes are a lot more spacious and a lot bulkier because they’re made for flat and wide terrain compared to their diesel models that are made more compact that I concluded are maybe built for the boondocks.

Other Alternative: All Electric Motorhome

During these past years, motorhome manufacturers have been shifting their focus to making all-electric motorhomes. These babies are loaded up with powerful batteries that can power the engine as well as the RV amenities. As of my searching, I found a model that’s already out in the market. These are the Winnebago- J38SE and J33SE Class A commercial motorhomes.

Who this is for

Image Source: trucks.com

On their site, they claim that this ‘ground-breaking 100% Battery Electric Vehicle delivers 85–125 miles on a full charge, making it ideal for short-range, fixed-base applications’. So, it might make sense that these are for relatively short distance vacationers. If you do have electric car charging ports available on your route, this would be a dream.

I know this is all a new concept, but it goes without saying that these motorhomes are for electric vehicle enthusiasts. The concept of trying out a product for feedback would be very helpful to establish these products. We do it with phones, so why not do it with vehicles too. It’s like, in the beta stage of an app. 

Pros 

A humongous pro for electricity based RVs is it’s cleaner energy processing. This engine mechanism creates miles and miles of emissions-free traveling. Charging with a supercharger or fast charging using a charging port would take just around a few hours to fully charge the vehicle. Another pro is that you get to drive an electric vehicle! Yay, future!

Cons

The cons would be rooted in it still being a new concept. That said, not many charging stations are available throughout the states and the lack of standardization and universality of ports. That means, as of my research, you can’t charge your non-Tesla electric vehicle on a Tesla supercharger. Although other chargers are becoming more widely available, like the CCS charger. 

Even without superchargers, you might still make the trip by hooking up on motels or RV campsites. Although it is possible, it might take days to fully charge the electric RV when using anRV site hookup. But if you’re in for a staycation, this won’t be a problem.

All Electric RV Model Concepts to Watch Out for

Volkswagen has recently announced its working concept of an all-electric microbus camper! It’s an all-electric version of the classic Volkswagen microbus, the 60’s, 70’s era van- The Shag Wagon, as some would so eloquently put it. I got so intrigued by this because they maintained the vintage feel of the camper with the modern touches. It has an adorable futuristic-looking steering wheel that looks like a tablet! This modern microbus is projected to be available in 2022.

Also, Tesla has released an image rendering and concept of a motorhome based on its semi truck engine. This is rumored to cost only $180,000 which is just peanuts in the RV world. Seeing that I couldn’t look for a timeline on when this vehicle would be available, I’d figure that this would be a reality soon, looking at Tesla’s timeline on its projects. 

Conclusion

Diesel motorhomes are great for those who won’t mind paying more for the torque, power, and comfort these motorhomes give. Gas motorhomes, on the other hand, are a more practical option for those who are looking to enjoy leisurely rides on flat terrain. One must keep in mind that neither a diesel-based RV nor gas-based RV is any better than the other. You just have to be aware of the trip itineraries you would want to take with the RV you’re going to rent or buy and pick according to what best fits your needs.

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