20% off rentals until the end of March 2027 with code SNOW20• 20% off rentals until the end of March 2027 with code SNOW20• 20% off rentals until the end of March 2027 with code SNOW20• 20% off rentals until the end of March 2027 with code SNOW20•

Fuel consumption in a Campervan: how many litres you need for your trip

Avtodom, ki toči gorivo na bencinskem servisu
October 22, 2026
Motorhomes typically consume between 6.3 and 7.5 litres per 100 km at 80 km/h, between 8.1 and 9.2 litres at 100 km/h, and between 11 and 14 litres per 100 km at 130 km/h, according to ADAC tests. To calculate your fuel requirements quickly, multiply the estimated litres per 100 km by the distance in kilometres and divide by 100. The result is the number of litres you will need for the journey. Since official figures often underestimate real-world consumption, it is worth allowing for a safety margin.
In brief:
  • A European report states that real-world fuel consumption exceeds the official WLTP figure by an average of 1 to 1.5 litres per 100 km.
  • At a moderate driving speed and a consumption rate of 8.2 litres per 100 km, a 700 km weekly trip requires approximately 57.4 litres, excluding any additional reserve.
  • A full water tank, gas cylinders, luggage and hilly roads increase fuel consumption, particularly on climbs and during acceleration. Remove unnecessary equipment and avoid carrying water you will not need.
  • Driving at around 100 km/h instead of 130 km/h can save several litres per 100 km, especially on long motorway stretches.
Campervan
campervan.si
Plan your journey with fewer unknowns
Choose a campervan for exploring Slovenia and estimate your fuel consumption before departure based on your planned route.
Explore campervans

Table of contents

What affects motorhome fuel consumption

Fuel consumption in a motorhome is not a fixed figure. It is the result of several factors working together. Understanding these factors helps you make a realistic estimate for your trip and identify what you can adjust yourself. Speed is the single biggest factor. Because a motorhome has a tall, relatively flat front, aerodynamic drag increases more rapidly at higher speeds than it does in a passenger car. As a result, consumption can rise by more than 25 to 30 per cent between 80 and 130 km/h. Vehicle weight also matters: a full water tank, two full gas cylinders, luggage and additional equipment all increase the vehicle’s weight, affecting fuel consumption on climbs and during acceleration. Terrain is another important factor. Mountain roads with successive climbs and bends use considerably more fuel than driving at a steady speed on flat roads, regardless of how carefully you drive. Tyres, tyre pressure and regular engine maintenance also affect consumption, although generally less dramatically than speed or terrain. Factors to consider when planning your route:
  • speed and road profile (motorways versus hilly regional roads)
  • the total weight of the vehicle, including equipment, water and passengers
  • ambient temperature and the use of air conditioning or heating
  • tyre condition and correct tyre pressure
  • driving style and the use of assistance systems such as Eco mode
Expert tip: Check your tyre pressure before every long journey. Underinflated tyres can noticeably increase fuel consumption, even during everyday driving.
Campervan rental | Campervan.si, Brnčičeva ulica 13, 1231 Ljubljana
Campervan
Start planning your trip in person
When viewing a campervan, you can consider how its size and equipment would suit your planned journey around Slovenia.
Campervan rental | Campervan.si
Brnčičeva ulica 13, 1231 Ljubljana
Get directions

How to estimate fuel consumption for your trip: steps and adjustments to WLTP figures

The starting point for any estimate is the vehicle’s official fuel-consumption figure, which you can find in the vehicle documentation or obtain from the rental company. This figure is based on the standardised WLTP test, but real-world fuel consumption often differs from the test result. Follow these steps to make a realistic estimate:
  1. Find the official WLTP fuel-consumption figure for your motorhome model.
  2. Add a correction factor to account for the difference between test conditions and real-world driving.
  3. Adjust the figure according to the expected average speed on your route.
  4. Allow for the additional load from luggage, water and passengers.
  5. Multiply the final adjusted figure by the distance and divide by 100 to calculate the litres required.
The European report COM(2024) 122 final states that real-world fuel consumption is, on average, 1 to 1.5 litres per 100 km higher than official WLTP figures, which can quickly add up to an extra tank of fuel on a long journey. Consider this example: your motorhome has an official fuel-consumption figure of 7.0 l/100 km. To account for the difference between WLTP testing and real-world driving, add approximately 1.2 l/100 km, giving an initial real-world estimate of around 8.2 l/100 km at a moderate speed. If you then spend most of the journey on the motorway at 130 km/h, consumption will increase further, in line with the ADAC test figures, and may approach 11 to 12 litres per 100 km. If the vehicle is loaded with water, gas and luggage, allow an additional margin, as extra weight always increases fuel consumption on climbs. Example of motorhome fuel consumption, from official figures to motorway driving

Practical tips for reducing fuel consumption when driving a motorhome

A few simple driving habits can noticeably reduce fuel consumption, particularly over long distances where the savings add up. The biggest difference comes from maintaining a moderate, steady speed: according to ADAC figures, driving at 100 km/h instead of 130 km/h can save several litres per 100 km. Where available, Eco mode adjusts gear changes and engine revs. It is most effective during calm, steady driving on regional roads. On motorways at high speeds, the savings are less noticeable, as illustrated by long-term tests of modern vehicles with similar systems, such as this long-term test of a van with an Eco function. Packing and weight distribution matter too: unnecessary equipment, full water tanks you will not use, or heavy bicycles mounted on the rear of the vehicle can increase consumption more than most travellers realise. Practical steps to reduce fuel consumption:
  • drive smoothly, avoiding sudden acceleration and braking
  • check tyre pressure regularly, as underinflation increases rolling resistance
  • remove unnecessary equipment and luggage before setting off
  • plan a route with fewer motorway sections where practical
  • keep up with scheduled servicing, as a poorly maintained engine can use more fuel
In winter, the additional fuel used for cabin heating or warming up the engine after starting is not insignificant. When travelling in winter, expect slightly higher consumption than in summer, particularly on short journeys when the engine does not reach its optimal operating temperature. Expert tip: On mountain passes, reduce your speed before starting a climb rather than braking halfway up. This helps you use less fuel than late braking followed by acceleration.

Fuel calculation examples: how much fuel you need for typical trips in Slovenia

Practical examples make it easier to plan your fuel supply and travel budget. Let us use the adjusted estimate of 8.2 l/100 km at a moderate speed calculated above for three typical journeys in Slovenia.
  1. Weekend trip, 200 km: at 8.2 l/100 km, you will need approximately 16.4 litres of fuel.
  2. Week-long trip, 700 km: the same consumption rate means around 57.4 litres for the entire journey.
  3. Longer transfer, 1,200 km, for example towards the coast or the Alps: fuel consumption will be approximately 98.4 litres.
Speed plays a key role in these calculations. According to ADAC tests, comparable motorhomes consume between 6.3 and 7.5 l/100 km at 80 km/h, between 8.1 and 9.2 l/100 km at 100 km/h, and between 11 and 14 l/100 km at 130 km/h.
Speed Fuel consumption (l/100 km)
80 km/h 6.3 to 7.5
100 km/h 8.1 to 9.2
130 km/h 11 to 14
In Slovenia, where you can quickly go from motorways to hilly regional roads heading towards the Alps or the coast, we recommend allowing for a fuel reserve when planning your journey and timing your stops according to the availability of petrol stations along the route.

The author’s perspective: how we advise customers about fuel consumption

When customers make a reservation, we prefer to give them a realistic estimate of fuel consumption rather than an optimistic figure from a brochure. For our fleet, which includes the Mercedes V Marco Polo and Ford Nugget Plus, we advise customers on expected consumption based on known test figures and our experience driving on Slovenian roads, from flat motorways to mountain passes. The difference between relaxed and fast driving quickly becomes apparent in the number of fuel stops you need to make. If you are planning a trip and would like a more precise estimate for your chosen vehicle, get in touch with us when making your reservation.
— Rok

Frequently asked questions

How much fuel does a motorhome use per 100 kilometres?

Depending on the speed and motorhome model, consumption is between 6.3 and 7.5 litres per 100 km at 80 km/h, between 8.1 and 9.2 litres at 100 km/h, and between 11 and 14 litres at 130 km/h, according to ADAC tests. A loaded vehicle carrying water, gas and luggage will use slightly more fuel than these figures suggest.

Why does a motorhome use more fuel than the official figure?

Official WLTP figures measure fuel consumption under standardised test conditions that do not fully reflect real-world driving with a load and changing terrain. A European report states that real-world consumption is, on average, 1 to 1.5 litres per 100 km higher than the official figure.

How can I reduce fuel consumption when driving a motorhome?

The most effective approach is to maintain a moderate, steady speed of around 100 km/h instead of driving at 130 km/h, which can reduce consumption by several litres per 100 km. Regularly checking tyre pressure, removing unnecessary weight and keeping up with scheduled servicing also help.

How much fuel should I allow for a week-long trip around Slovenia?

The amount of fuel required for a week-long trip depends on the distance, vehicle, speed and terrain. Multiply your expected consumption in litres per 100 km by the journey distance and divide the result by 100, then allow for an additional safety margin. The exact amount will vary depending on the vehicle you choose and the route, so adjust your estimate according to whether your journey passes through mountainous or flat areas.

Sources

For more detailed information on fuel consumption, we recommend consulting the European report on real-world fuel consumption, the 2022 data on emissions and fuel consumption, the VECTO tool and ADAC vehicle tests.
CCampervan
Ask us about a campervan for your trip
Contact us to learn more about renting a campervan for exploring Slovenia and planning your journey.
Share this