The Ultimate Guide to RV Gas Mileage

Last updated on May 18th, 2021 at 01:52 pm. Originally published on January 21st, 2020

After the major cost of acquiring the recreational vehicle itself, keeping it full of gas or diesel might just be the most expensive part of owning and operating a camper. Even the smallest RVs are large, heavy vehicles — it takes a lot of power to move all that weight down the road at speed!

That power has to come from somewhere. And since they’re still working out the kinks on those fairy-dust-powered RVs, right now, that “somewhere” is fossil fuel. But how bad is RV gas mileage, really? How many miles to the gallon does an RV get? What kind of mileage differences can you expect to see between, say, a Class C versus a Class A motorcoach?

We won’t beat around the bush: there’s no such thing as an RV that’s cheap to tote around. But some rigs do get better mileage than others, and there are some simple steps you can take to get the most bang — or combustion — for your buck.

In this post, we’re going to talk about all things RV MPG, from common myths and questions to how much gas an RV holds in the first place. By the time we’re done, gas might not be any cheaper… but you’ll be a lot more informed about how to get your rig fueled up and ready to travel as efficiently as possible!

How much does it cost in gas to drive an RV?

Obviously, the cost of gas varies wildly depending on what part of the country — or, in some cases, even what part of the county you’re in. It also fluctuates with the market, dipping when the commodity is doing well and going higher when it’s harder to come by.

But even when gas is at an all-time low, when you start looking at the average mpg on your camper, you might not be feeling so blasé about pump prices.

If you’re traveling in a Class A or Class C motorhome — even a relatively small one — you’re almost surely looking at less than 15 miles to the gallon. And many large RVs get as few as 4 or 6!

Although towable RVs are hauled by trucks which may see higher MPG ratings (especially if they’re newer models), the extra weight does factor in and affect the overall mileage. There’s no two ways around it: driving something heavy requires a whole lot of fuel.

There’s no easy answer to the question, how much does it cost in gas to drive an RV? The answer will depend not only on what type and size of rig you’re driving, but also how far you’re going, what kind of terrain you’re traveling over, your speed, and more.

But the information throughout the rest of this article can help you gauge — pun totally intended — approximately how much you might expect to pour into your tank throughout your travels. Here’s what you need to know about the mileage for different RV classes, as well as tricks to help you save gas money.

How much is the standard MPG for each RV class?

Once again, we must warn: there is no single, easy answer. Although the different classes share similarities, even within the categories, there’s a lot of variation in size and weight, which are major factors in determining mileage.

That said, we can talk about average figures by class. Here’s how it breaks down.

Class A RVs

These large, luxurious models are some of the heaviest on the road. Along with all those fancy appliances and premium furniture, they’ve also got structural and mechanical components including slide-outs, a weighty power train, and more.

Thus, it’s not actually that surprising to learn that a Class A might see about 6-8 miles per gallon on average, and sometimes as little as 4 MPG when traveling in suboptimal conditions (like over steep terrain, with hills).

Class C RVs

Class C motorhomes are an attractive option for those who want a similar level of luxury as what you might get in a Class A, but don’t want to spend quite as much to get there. Along with the actual price of the vehicle being lower, Class As also get substantially better gas mileage… though they certainly still won’t be winning any awards with their 10-13 MPG figure.

Travel Trailers

Travel trailer mileage is all over the map, varying depending on the size of the trailer as well as the capacity and power of the tow vehicle. For instance, a small Casita travel trailer towed behind a Ford F150 might get around 12 miles to the gallon, whereas a larger fifth wheel trailer is probably going to be more costly to run, even behind a one-ton truck. (Then again, some owners report seeing as many as 15 or 16 mpg with their trailers. It all depends!)

Class B Sleeper Vans and Small RVs

If you’re interested in traveling in a converted van, sleeper van, or micro camper, you’ll earn back what you lose in luxury and space in gas savings. These tiny RVs are at the highest end of the MPG spectrum in the RV world, sometimes seeing as much as 15 or 18 miles to the gallon.

When in doubt, you can ask your RV dealer directly about the estimated mileage for a vehicle before you purchase it.

Then, you can use this figure along with your RV’s gas tank size to figure out about how much it’ll cost you to fill the tank — and how far you can get on that fill.

For example, let’s say you’re driving a 40 foot class A RV with a 60 gallon gas tank. If gas in your area is about $3.00 per gallon, that means one fill will cost you $180 — and get you about 360 miles (using 6 miles per each of the 60 gallons in this equation).

Once you know the basic cost of getting a certain distance away, you’ll have a better foundation from which to start planning feasible destinations. You’ll know how far you can afford to go, in other words!

What RV has the best gas mileage?

As you can see from the ranges above, it’s not that cut and dried to do a simple RV mileage comparison. Although larger vehicles tend to draw more fuel than smaller ones, factors such as your RV’s age and what kind of terrain you’re driving on will play a serious part in how far you can hope to get on a single fill. (For example, driving in the mountains adds strain to your engine, which means your fuel efficiency will drop lower.)

Older RVs also tend to get worse gas mileage than newer ones, just like regular street vehicles. That said, in general, if you’re looking for an RV with great gas mileage, smaller is better.

How much gas does an RV hold?

Mileage is one thing. And it’s annoying to have to spend a ton of dough on keeping your tank full.

But it’s almost equally annoying to have to keep stopping for gas every seven seconds! Given how much fuel they burn, RVs must be able to hold a decent amount of it… right?

Here’s how much each class holds on average.

Class A RVs

As we’ve already stated, these RVs are the largest, most luxurious, and also gas-burningest on the road. Thus, they tend to have the largest gas tanks in order to feed their voracious, constant appetites: they range from about 70 to over 100 gallons, with some holding as much as 150!

Class C RVs

Class C RVs still need a lot of gas, but their tanks tend to be a bit smaller than their Class A cousins. What’s more, Class C RVs come in a very wide range of sizes, from 17-foot Minnie Winnies to lengthy 30+ foot rigs with multiple slide outs.

Although it will depend on the exact shape, style, and footprint of your Class C, you can expect the rig to hold somewhere between about 30 and 70 gallons.

Class B RVs and Sleeper Vans

Sleeper vans, Class B motorcoaches and other small drivable RVs have much smaller tanks than Class A and Class C rigs. You should probably expect to see about 25 gallons of capacity, but again, the exact figure will depend on your manufacturer and model.

Travel Trailers and Towables

Travel trailers and towables, of course, don’t have fuel tanks of their own — they’re dependent on the power of the vehicle that’s towing them! Thus, in this case, you’ll want to look into the tank capacity of your tow vehicle. That said, most trucks tend to hold between 15-30 gallons. And as with all vehicles, the newer the truck, the better its gas mileage is likely to be… though again, towing a trailer will have a major negative impact on those idealistic published figures.


Here are some of the most commonly asked questions about RV MPG.

Is diesel more fuel-efficient than gasoline in an RV?

Diesel is a more efficient fuel source in all cases, including in your RV. That’s why many Class A motorhomes are powered by strong, rear diesel engines that push them along the road (thus the name “diesel pushers”).

According to, “Diesel fuel contains roughly 10% to 15% more energy than gasoline. So, diesel vehicles can often go about 20% to 35% farther on a gallon of fuel than their gasoline counterparts.” As in all cases, newer engines are more highly developed, and often burn cleaner and more quietly than gas-powered models (or older diesel engines).

That said, diesel does have its drawbacks; in some cases it’s more expensive than gas, and it can be harder to find. In our opinion, it wouldn’t be worth foregoing an RV you love just because it’s powered by gas as opposed to diesel, but it is important to understand the differences between these two fuel options.

Gross Vehicle Weight: How does it effect MPG?

Gross Vehicle Weight is the total weight your RV can reach while remaining road safe. And yes, heavier objects need more fuel to burn… which means that an RV with a higher GVW rating stands to be less fuel efficient.

That said, just because an RV can reach up to a certain weight doesn’t mean it should, or that you have to. Reducing the overall weight of your rig is one of the best ways to save money on RV gas mileage, and you can do so by avoiding traveling with water in the tanks or a pantry stocked full of food. Just make a grocery store trip as soon as you pull into the campground!

Adding a fuel economy chip: how do you do it?

A fuel economy chip is a piece of technology that purports to help you increase the fuel efficiency of your engine. It does so by optimizing your torque, leading to better performance and better gas mileage, which is a pretty compelling argument.

It is possible to put a fuel economy chip into a motorhome to achieve the same results, and many RV repair shops offer the service. Here’s our guide on how to find an RV repair service you can actually trust to do the work right, for the right price.

What are the best ways to save fuel in my RV?

So now that you’ve heard the bad news about average RV gas mileage, how can you work to mitigate the expense?

Luckily, there are a number of ways to save money on fueling your rig.

First of all, always use an app like GasBuddy to find the cheapest gas available in your area. No matter how many miles per gallon your motorhome gets, it’s always worthwhile to find the cheapest source of fuel. When you’re talking about such a big fill, even a few cents per gallon adds up!

Secondly, carefully consider whether you want to purchase a gas or diesel RV. Diesel rigs sometimes tend to have better fuel efficiency, although the cost of the fuel itself might be slightly more expensive and harder to find.

Finally, keep gas mileage in mind whenever you’re traveling in an RV. That means, for example, no random road trips without a plan for where you’re going or how far you’ll have to drive to get there. Always run your prospective destinations through an RV gas mileage calculator in order to discover the real cost of getting to where you’re going. Then, you’ll be able to pick destinations wisely and save money on fuel — and have enough leftover to spend on campground fees, food, and fun when you get there!

RV MPG: Common Myths

Given this information, you might think that RVing is just about the least-green way to travel there is. But it’s actually not true! (And thank goodness, because we’re big fans of both the Earth and of RVing.

Even though RVs aren’t the most gas-efficient method of travel, they’re still considered far greener than traditional trips that utilize airplanes and hotels. After all, the carbon footprint of one plane flight is a pretty big deal… and then, you still have to factor in all of the expenses and production that go into accommodation and food costs for the trip.

Plus, the flexibility and convenience of being able to take all your stuff with you and set your own itinerary and route is truly worth spending a little extra at the pump. Just make the effort to be as green as possible in other ways to offset your damages; finding ways to save water on the road and make your trip a little greener can be both easy and fun.

RV Gas Mileage Calculator

In the end, the only way to truly understand how much it’s going to cost to keep your rig fueled up is to observe how much you’re spending on fuel once you’ve already gotten going. You can make theoretical guesses by using your average mileage and fuel costs as demonstrated above, but in real life, speed, terrain, wind, and a whole host of other factors both in and out of your control will affect the bottom line.

That said, RVing is a special enough travel style that the fuel cost associated with it might just be worth the burden.

Finally, don’t forget to slow down while you’re taking your grand adventure. Not only will you get better fuel efficiency, but you’ll get to actually enjoy the journey.

This post may contain affiliate links.



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