Gas Mileage on Motorhomes: Ultimate Guide for 2023

Are you in the market for a new motorhome? The layout, the number of rooms, bathroom, and kitchen facilities are things you’re going to think about, but for most new motorhome owners fuel efficiency is a top priority.

Owning a motorhome is a sizeable investment and not just the initial cost. There’s maintenance to consider, repairs, possible upgrades, and winterizing which all come at a cost. It, therefore, makes sense to try and save money when it comes to running costs.

As we all know, fuel can be very expensive and gas prices go up far more than it goes down.

If you find a motorhome that’s got great fuel economy, you’ll be able to enjoy RVing more often and travel further for your motorhome adventures.

In this guide, you’ll find out what kind of fuel economy you can expect from your motorhome RV. Youll also discover what you can do to get better gas mileage

What’s The Average Fuel Mileage For Motorhomes?

On average, you can expect a diesel motorhome to get around 30 miles per gallon. A petrol camper or motorhome, on the other hand, will achieve a mile-per-gallon range of 8-10 miles per gallon.

The average gas mileage for your motorhome varies for several reasons. The size of your motorhome affects fuel economy. Gas mileage tends to be worse the larger and heavier your motorhome. Believe it or not, fuel economy is also affected by the shape of your motorhome. Finally, the fact that you have a diesel RV also makes a difference because diesel engines are more fuel-efficient.

What is the Fuel Mileage for the Different Classes of Motorhomes?

When it comes to different motorhome classes, there are some similarities. However, even within the three motorhome classes, there are sizeable differences in terms of size and weight.

There is no single, easy answer but it is possible to give you a general estimate for the fuel efficiency of each RV class.

Class A Motorhome Gas Mileage

The average mileage for a Class A motorhome is between 7 and 13 miles per gallon.

Class A motorhomes are the worst in terms of miles per gallon. The reason is their size. They are typically large and have a bus-like configuration. They also tend to be rather box-like and have flat sides just like a bus.

The large size and flat features that are typical of a Class A motorhome make road travel hard. this is because of the wind force and the fact that they are heavy to move around.

The flat front of the RV has to push against the wind and there is no easy way for the wind to move around or glide off the vehicle.

In other words, American A Class motorhomes are bricks on wheels. However, European emissions regulations actually exist so most UK A Class vehicles are streamlined to a much greater extent than American models,

The fact that Class A motorhomes are so heavy also works against them in terms of better fuel economy. On average, an American A Class can weight as much as 17.5 tons. That’s a lot of vehicle the engine has to pull which means it’s going to eat up fuel.

On the other hand, most European motorhomes have a max permissible mass between 3500kg and 5000kg. A class motorhomes in the 7500 – 10,000kg range are quite rare and motorhomes heavier than that are a tiny percentage.

Let’s give you a few examples:

• Fleetwood Bounder – 8.5 mpg
• Forest River Berkshire – 9 mpg
• Monaco Vesta – 10.7 mpg
• Newell Coach Custom 45 – 8 mpg
• Thor Palazzo – 10 mpg

Class B Motorhome Gas Mileage

You can expect the best gas mileage from a Class B motorhome. This is all down to the shape and weight. They are sleek and the motorhome’s front end is slanted, much more aerodynamic and streamlined.

The smooth transition to the vehicle’s roof means the motorhome gets better mileage. The engine doesn’t have to work as hard as it does in a Class A or Class C motorhome.

Another positive factor is the fact that a Class B motorhome is the lightest class you can get. The engine doesn’t have to work as hard which improves the mileage.

The average mileage for a Class B motorhome is between 18 and 25 miles per gallon.

Let’s give you a few examples:

• Winnebago Travato 59G – 20 mpg
• Airstream Grand Tour Twin – 17 mpg
• Roadtrek Sprinter RS Adventurous – 20 mpg
• Leisure Vans Serenity Standard Class B – 16 mpg
• Thor Motor Coach Gemini 125X – 18 mpg

Class C Motorhome Gas Mileage

Class C motorhomes come in second place for best mileage per gallon. This is of course because of their weight and build. Class C motorhomes are built similarly to Class B’s but they have worse gas mileage because of a few differences.

Class C motorhomes have a sleek, smooth front end, but there is a bunk in the trailer portion that hangs out over the cab of the cockpit. This is not a very aero-dynamic feature and obstructs the airflow over the vehicle.

A Class motorhome also weighs a little more than a Class B motorhome, because of the additional trailer space. They also tend to be bigger overall.

The average mileage for a Class C motorhome is between 14 and 18 miles per gallon.

Let’s give you a few examples:

• Forest River 3010DS – 9 mpg
• Thor Freedom Elite 24FE – 13 mpg
• Itasca Navion Motorhome – 18 mpg
• Winnebago View 24V – 16.5 mpg
• Coach House Platinum III 250 ST – 16 mpg

Which Motorhome Gets the Best Gas Mileage?

Out of all three types of motorhomes, Class B comes out on top in terms of the best mileage.

Coming in a close second are the Class C motorhomes.

In last place are Class A motorhomes. You can expect the worst mileage with one of these.

What Factors Affect the Gas Mileage of a Motorhome?

How many miles per gallon you get from your motorhome will depend on many different factors. It very much depends on the way you drive your motorhome.

For example, your motorhome is at its most fuel economic when you drive at around 50-60 mph.

If you find yourself driving uphill, on uneven terrain, or on a curvy road, you can expect the gas mileage to be at its worst.

Your gas mileage will likely improve when you drive on flat, straight roads, drive downhill, or are coasting.

What other factors make motorhomes so inefficient? Let’s introduce the other major factors so you better understand.

Motorhome Weight

As you might have already guessed, the larger your motorhome the lower its mileage. Motorhomes are large and can accommodate you and your family.

For American motorhomes, the engine alone weighs between 500 and 2500 pounds. The travelling weight of your home on wheels will be between 10,000 and 40,000 pounds.

Most European motorhomes have a straight 4 engine 2.0 -2.3l displacement. Max engine weight is around 300kg (661pounds).

Such a heavy motorhome weight means the engine has to work super hard to drive you and your trappings around.

Motorhome Size

You’re going to want a large motorhome because there’s more room to move around, and it’s more comfortable and spacious. However, space comes at a cost.

The size of your motorhome determines the amount of gas it uses. This means less mileage.

It’s not just the size in general. The length of your motorhome also contributes to its fuel efficiency. The longer the motorhome, the worse the gas mileage.

Gas mileage can also vary depending on the shape.

Turbocharging

All European motorhomes are turbo charged Diesel. Only very old motorhomes are non-turbo. Turbo Diesel engines are much more efficient than non-turbo engines so they are pretty much required to pass European emissions regulations.

A turbocharged engine can turn into a fuel hog under hard acceleration. If you drive your turbocharged motorhome carefully and with discipline, it will offer fuel efficiency gains.

Direct Fuel Injection

Direct fuel injection can increase your motorhome’s engine combustion efficiency and lower fuel consumption by between 1% and 3%. This is because it allows for better control of the fuel-air mixture.

Horsepower

Horsepower is a major factor in a vehicle’s fuel consumption.

Understandably, both underpowered and overpowered vans can lead to increased fuel consumption. The key to optimal mileage lies in a balance, where the vehicle’s load aligns perfectly with the engine power.

European motorhome manufacturers often focus on this balance, selecting horsepower that suits the vehicle’s weight and air resistance to adhere to stringent emissions targets.

On the other hand, American manufacturers, faced with fewer emissions regulations, cater to the preferences of wealthier customers, usually opting for large displacement, low power output V8 engines. However, tuning these engines for greater power output post-purchase can significantly degrade fuel economy.

Axle Ratio

Axle ratio is a technical term. It refers to the number of times your motorhome’s driveshaft turns in order to move the wheels through one full rotation.

A motorhome with a high axle ratio tends to be less fuel economic.

Most European vans have transverse mounted engines and are front wheel drive.

Due to Americans demanding very wide straight 6 or V engines they tend to be mounted inline and have a drive shaft which goes to the rear axle. Due to high torque V8 engines they usually need a torque converter as well to stop them smashing the differential.

Weather

A basic rule of thumb states that driving your motorhome in cold weather and winter driving conditions can significantly reduce fuel economy. In city driving, for example, it can be 15% lower at 20°F than it would be at 77°F. For short trips of 3-4 miles, it can drop by as much as 24%.

However, the things a bit different with modern motorhomes.

In Europe, due to to strict emissions targets here there is a lot of equipment which controls fuel consumption in a variety of operating conditions. The engine will reduce its cooling to an absolute minimum in cold conditions.

Diesel is preheated before injection so fuel input temperature isn’t affected. Engine warmup will take a little longer but motorhomes aren’t used for short trips usually so longer warmup has a negligible effect.

Once everything is at operating temperature, external ambient has almost no affect as the engine’s computer will compensate.

Driving Behaviour

How you drive your motorhome can have a significant impact on the amount of fuel it uses. If you like to put your pedal to the metal as soon as the light turns green, expect it to reduce the engine’s fuel efficiency.

Тowing a Car Behind Your Motorhome

If you regularly tow with your motorhome you should notice a difference in its fuel economy. Even if you’re towing a compact and lightweight car, the engine of the motorhome is having to work harder because of the extra weight you’re pulling.

When an engine has to work harder, it requires more fuel and efficiency is affected.

Tyre Pressure

If your tyres are the slightest bit underinflated it can significantly impact your RVs mpg. When the air pressure in your tyres is low, it expands the tyre’s footprint and increases the weight placed on the tread. This then increases friction and drag and means the engine has to work harder.

If you’re out on a long journey in your motorhome, it can make a difference of between one and five fewer miles per gallon.

Can Air And Fuel Filters Affect Motorhome MPG?

For a combustion engine to work efficiently, it requires clean fuel and air, mixed in the correct ratios.

If the air and fuel filters are dirty it gradually impacts the engine performance and fuel efficiency. If your motorhome has an older petrol-powered engine, carbon deposits, and engine wear also affect performance.

You can seriously affect the lifespan of a filter by doing the following:

• Regularly driving on dusty roads
• Driving where the pollen count is high
• Frequently running your tank down to the fuel warning light

Do Diesel Motorhomes Get Better Mileage Than Gas Motorhomes?

If fuel economy is a big concern for you, you might want to consider a diesel rather than a petrol-powered motorhome. Diesel engines get better mileage.

• Diesel provides more energy than petrol by around 10% to 15%. This helps a diesel powered RV to be more efficient.
• A diesel motorhome will be 20% to 35% better on fuel than a petrol-powered motorhome because it is more energy efficient.
• You’ll be able to drive a diesel-powered motorhome further on the same amount of fuel as a petrol motorhome might.

How to Get Better Motorhome Gas Mileage?

With all this talk about motorhome inefficiency, you might be thinking there’s nothing you can do apart from suck it up and pay the fuel costs. Lucky for you, it is possible to improve your motorhome gas mileage. Consider the following if you’re concerned about saving gas:

• Pack Light: The lighter your motorhome, the more fuel-efficient it’ll be. Anything you put inside your motorhome will increase its weight and decrease fuel efficiency so try to travel as light as possible.
• Keep up with Motorhome Maintenance: General motorhome maintenance is important not just for the life of your vehicle, but also for better gas mileage. The gas engine will run better and other parts of the motorhome will function efficiently. Maintenance to take care of includes:
  • Tyre pressures
  • Engine check-ups
  • Fluid check-ups and replacement
  • Brake replacement
  • Tyre rotation and replacement
  • General cleaning internally and externally
• Slow Down: The optimum speed for the best fuel economy is around 60 mph. For the best fuel mileage possible, keep control of your accelerator foot.
• Drive a Smaller Motorhome: If you drive a smaller motorhome, it’s going to be more fuel efficient. You’ll get the best fuel economy with a Class B motorhome.
• Use Cruise Control: When you’re not using cruise control, the speed at which you drive tends to fluctuate more. These fluctuations make your engine pull harder because it is continually making adjustments. Set your cruise control and the speed of your driving won’t fluctuate as much and your overall fuel mileage will improve.
• Avoid Traffic: When you’re in traffic it’s a continual stop-and-go style of driving. Fluctuations like these pull on the engine and eat up fuel. Try to stick to areas that are less populated. Inner city driving in particular will drink the fuel.
• Drive Smoothly: Rough driving is something else that can contribute to poor gas mileage. Driving on bumpy roads or off-road dramatically reduces your mpg.
• Use Less Air Conditioning: While it might make driving more comfortable if you’ve got the air conditioning unit on, it’s also going to contribute to bad gas mileage. When the AC is running it pulls on the engine. It’s not as much of a pull as some of the other factors in this list, but it can make a difference of around 1 mpg.
• Don’t Leave Your Engine Running: This is another factor that’s quite small but is still something that makes a difference. Admittedly, leaving the engine running uses much less fuel than when your motorhome is moving, but it is still going to impact your fuel mileage.
• Motorhome Tyres & Inflation Levels: Under-inflated tyres can lower your gas mileage. When your tyres are correctly inflated it boosts your mileage and also helps them last longer. The actual tyres themselves can also be important when it comes to optimising fuel economy. Choose tyres that are durable but lightweight. Upsizing your wheels can also make a difference.
• Get The Junk Out Of The Boot: While it’s very tempting to take everything with you including the kitchen sink, think about what you’re packing because all the extra weight reduces your fuel mileage per gallon.
• Use The Recommended Motor Oil: There are plenty of motor oils to choose from, but you want one that is best suited for your motorhome. Stick with the manufacturer’s recommended oil and if you can’t find what’s on their list, ask about alternatives.
• Give Your Brakes A Break: Try to maintain a steady speed and avoid suddenly stopping or regularly applying the brakes. Gentle acceleration and a steady pace mean your engine is less stressed and your fuel economy will be better.
• Replace Your Dirty Air Filters: Clean air filters allow your engine to draw air freely. Dust, dirt, and other particles clogging up the filters make your motorhome work harder and reduce efficiency.
• Fill Your Tank Early in The Morning or Late at Night: Petrol is more dense in the morning. As the temperature rises during the day, the molecules expand and you’ll get less for your money.
• Go for Smaller Motorhomes: A smaller motorhome will generally be more fuel efficient because of its smaller size and lower weight.
• Plan your journey: The more you drive the more fuel your motorhome consumes so it makes sense to take the time and plan your route exactly. Try to avoid winding roads and those that have several stops. Minimise the number of miles you drive and try to avoid routes that involve lots of accelerating and decelerating.

How To Calculate Gas Mileage (MPG)

To help you gauge how much fuel your motorhome is using, take the following steps.

• Fill up the fuel tank at your local fuel station to the fuel cutoff level
• Reset the trip computer
• Drive until your fuel gauge is telling you to add more fuel
• Fill up again to the same cutoff level
• Record the number of gallons it takes to re-fill and also the miles reading on the trip counter
• Reset the motorhome’s trip
• The formula to calculate gas mileage is as follows: Miles driven ÷ gallons used to refill the tank.

For example:

If the trip shows 250 miles since your last fill-up and it took 20 gallons to refill the tank, your mpg is 250 ÷ 20 = 12.5 mpg

Conclusion

As you now appreciate, fuel economy varies considerably depending on the individual motorhome. In addition, there are numerous other factors that can affect how much petrol or diesel your motorhome guzzles when out on the road. Ultimately, you need to decide for yourself what is most important.

FAQs

What’s the best way to save on fuel in my Motorhome?

There are many things you can do if you want to save on fuel when enjoying a road trip in your motorhome. Here are some suggestions:

• The most fuel-efficient speed is between 55 and 65 miles per hour
• Driving consistently will cut your fuel expenditure
• Keep your tyres correctly inflated
• Pack light
• Find the best petrol station for the cheapest gas