Motorway or A-road in a motorhome : which route uses less fuel ?

When planning a motorhome road trip, people tend to think about the best places to spend the night and convenient service areas… and not so much about fuel consumption. Yet, eco-driving in a motorhome lets you travel further on the same budget, while easing your impact on the planet at the same time. One question soon crops up around campsite tables and in conversations between travellers: is it better to take the motorway or the A-road to burn less fuel ? 

Understanding motorhome fuel consumption

Motorhome fuel consumption depends on several key factors: vehicle type (low-profile, A-class, camper van), engine, aerodynamics, load, wind, terrain and even outside temperature. The same journey can therefore show significant variations from one motorhome to another, or even from one day to the next - simply on account of a headwind or an overfilled storage compartment.

Speed and weight play a central role. The faster you drive, the greater the air resistance, and fuel consumption climbs sharply above around 100 km/h. Weight is also a major factor. A full fresh-water tank, bikes, an extra scooter or a paddleboard added to the load means the engine has to work harder, especially on uphill stretches.

Motorways vs A-roads : a comparison

Motorways and A-roads offer very different driving experience… and have very different impacts on your motorhome's fuel consumption.

Motorways

On the motorway, the big advantage is constant speed. You can settle at 110-120 km/h (or less to save fuel), keep a steady rhythm and avoid strings of roundabouts and villages. In theory, it's ideal for eco-driving, because an engine that runs at a stable rev range consumes less fuel than one that is constantly accelerating.

There are also fewer stops: no traffic lights, minimal congestion outside peak periods… and coming to a complete stop is a rare occurrence. The result ? You move away from stationary much less, which is when the engine consumes most fuel. Comfort isn't to be overlooked either: wide carriageways, frequent service areas, faster and less tiring journeys, especially handy when you're new to motorhoming.

The downside ? Fuel consumption can be higher due to speed. The closer you get to the speed limits, the thirstier the motorhome becomes, sometimes consuming several litres more per 100 km compared with driving at 80-90 km/h. On top of this, tolls can quickly eat into your budget, particularly for vehicles in the higher classification bands.

A-roads

On A-roads, you generally drive at a lower speed, around 80 km/h, sometimes less when passing through villages. This speed range is often idealfor a motorhome, keeping the engine and aerodynamics at a more efficient level.

The trade-off is frequent stops: traffic lights, roundabouts, speed limits, roadworks… Every stop means having to set off again from stationary, and these energy-intensive accelerations are what consume the most fuel on this type of journey, especially with a heavy vehicle.

The result ? Variable fuel consumption. You can get an excellent average on a nice flowing B-road, or burn almost as much as on the motorway if you pass through a string of villages in heavy traffic.

The A-road delivers potential savings on both fuel and tolls, especially if you accept a slower pace and take your time. It also offers varied scenery, characterful villages and unplanned stops with local producers: exactly what many travellers are looking for in a motorhome.

Impact on fuel consumption

Average speed is the first indicator to watch: a journey at a steady 110 km/h will generally consume more fuel than a smooth 80 km/h drive, but less than a 70 km/h average peppered with stops and traffic jams.

In a motorhome, the fuel-consumption “sweet spot” usually sits around 80-90 km/h.

Repeated acceleration and braking is a real fuel-guzzler. Anticipating roundabouts, easing off before a light or a slowdown, and using engine braking rather than hitting the brake at the last second all noticeably reduce fuel consumption. Terrain and road type also matter: a mountain A-road with hairpins and steep gradients will be more fuel-hungry than a flat motorway, even at a moderate speed.

A brief comparative analysis

The numbers vary, but we can offer some general guidance for a medium-sized motorhome.
•    On the motorway, many users report an estimated consumption of around 10-12 L/100 km at 110-115 km/h, sometimes more with a headwind or a heavy load.
•    On A-roads, at 80-90 km/h and with smooth driving, studies and user feedback report an estimated consumption 10 to 15% lower than on the motorway, for comparable terrain.

In practical terms, some reports indicate up to 12% lower fuel use on the same journey when favouring A-roads. In terms of fuel cost comparison, the A-road generally wins, especially once you add the absence of tolls to the difference in terms of litres consumed.

A few tips to reduce fuel consumption

Eco-driving starts with smooth driving :

•    Gradual acceleration
•    Steady speed
•    Respect the speed limits without constantly pushing to the maximum allowed
•    Minimise unnecessary braking, keep a safe distance, and feel free to drive a little below the limit if no one's behind you.

Anticipation is your best ally :

•    Look well ahead
•    Ease off the accelerator when approaching a red light
•    Use engine braking on descents
•    Adapt your pace to the environment.

When it comes to optimised loading, travelling light really makes a difference :

•    Reduce weight in storage lockers
•    Avoid driving with full water tanks unless essential
•    Check tyre pressures
•    Service the engine regularly.

The choice of route matters as much as the type of road. A free-flowing, open A-road can be perfect, while a steep, windy motorway will drink fuel. Before setting off with a motorhome hired from Evasia.fr, taking a few minutes to study the terrain, plan routes that bypass major cities and explore alternatives to congested routes can save you litres of fuel… and stress. In the end, it all depends on your speed, the terrain, the traffic… and your driving style. If your priority is fuel economy and you like to take your time, well-chosen A-roads will often be your best ally. If you have a long distance to cover in a day, or you are new to motorhome driving, the motorway will provide greater comfort.