How to use the calculator with a campervan or motorhome
- Under “Vehicle type”, choose “Campervan” for a van conversion (VW California, Ford Nugget, Mercedes Marco Polo, or a converted Fiat Ducato, Peugeot Boxer or Citroën Relay) and “Motorhome” for a low-profile or coachbuilt motorhome on a Fiat Ducato or similar chassis.
- For fuel economy, if you know it from filling up, use “My real figure”: it is the most reliable. Otherwise, use the vehicle’s official figure. Some motorhomes only list the base chassis figure, which doesn’t reflect the weight or shape of the finished vehicle.
- Calculate the route or enter the distance. If you plan to avoid motorways, adjust the road mix.
- Add travellers and luggage. With an official figure, the calculator already adds the kit you always carry: 100 kg (220 lb) in a campervan and 200 kg (440 lb) in a motorhome, for water, gas and camping gear.
How much fuel does a campervan or motorhome use?
German magazine promobil measures every vehicle it tests on the same route of about 300 km (190 miles): 13% town, 41% country roads and 46% motorway, mostly at 100 km/h (62 mph), with the water and gas tanks full.
| Type | L/100 km | mpg (UK) | mpg (US) |
|---|---|---|---|
| Campervan (van conversion) | 9–10 | 28–31 | 24–26 |
| Low-profile motorhome | 0.5–1 more than a campervan | – | – |
| A-class (integrated) | ≈ 1 more than a low-profile | – | – |
| Coachbuilt with over-cab bed | ≈ 12–13 | 22–24 | 18–20 |
On Spritmonitor.de, where drivers log every fill-up, the diesel Fiat Ducato averages 10.2 L/100 km (about 28 mpg UK, 23 mpg US) across 3,195 vehicles, including work vans, campervans and motorhomes. These are European diesel vehicles. In the US, if your motorhome’s gross vehicle weight rating (GVWR, on the driver’s door pillar) is above 8,500 lb, it has no official EPA figure, because heavier vehicles are exempt from fuel economy testing: measure your real mpg instead. What pushes these figures up or down: campervan and motorhome fuel consumption.
Speed, weight and aerodynamics
Speed changes a motorhome’s fuel use more than anything else. promobil measured a low-profile motorhome on a 140 hp Fiat Ducato, weighing about 3,000 kg, on the motorway: 9.3 L/100 km (30 mpg UK) at an average of 85 km/h (53 mph), 11.9 L/100 km (24 mpg UK) at 105 km/h (65 mph) and 17.5 L/100 km (16 mpg UK) at 120 km/h (75 mph). Air resistance grows with the square of speed, and a motorhome has a far bigger front than a car.
In the UK, motorhomes over 3.05 tonnes unladen have lower limits than cars on single and dual carriageways (50 and 60 mph), though the motorway limit is the same 70 mph. Slowing down is still the easiest way to save fuel.
Weight matters most in town and on hills. Germany’s ADAC adds 200 kg for water, gas and equipment when working out a motorhome’s travelling weight, and often finds motorhomes over their maximum permitted weight. How luggage, bikes and roof boxes affect fuel use: roof boxes and luggage.
Example: 500 miles with lots of motorway
| Vehicle | Fuel economy entered | Trip fuel economy | Fuel | Cost |
|---|---|---|---|---|
| Diesel campervan, two people, light luggage | 30 mpg (official) | 26.8 mpg | 85 litres | £123 |
| Diesel motorhome, two people, full luggage | 25 mpg (real) | 22.6 mpg | 101 litres | £146 |
The motorhome uses more than the real figure you entered because that figure is your everyday average, and this trip has much more motorway driving.
Frequently asked questions
What mpg does a motorhome get?
In promobil tests, a low-profile motorhome uses 0.5–1 L/100 km more than a campervan (28–31 mpg UK), and a coachbuilt with an over-cab bed about 22–24 mpg UK (18–20 mpg US). Speed and weight make a big difference.
What mpg does a campervan get?
About 28–31 mpg UK (24–26 mpg US) on mixed driving with plenty of motorway at 62 mph, according to promobil. More in town or at higher speeds.
Which figure do I use if my motorhome only lists the chassis mpg?
If you can, work out your real fuel economy by filling up from full to full (here’s how), and use “My real figure”. The base chassis figure doesn’t account for the weight or shape of the living area.
At what speed does a motorhome use least fuel?
The slower you drive on the motorway, the less it uses. promobil measured 30 mpg UK at an average of 53 mph, 24 mpg at 65 mph and 16 mpg at 75 mph with the same motorhome.
Does it account for water and luggage weight?
Yes. With an official figure, the calculator adds the usual kit (100 kg in campervans and 200 kg in motorhomes). Travellers and luggage are added in their own fields.
Sources
- promobil — So ermittelt promobil den Kraftstoffverbrauch
- promobil — Benzin und Diesel sparen im Reisemobil (85, 105 and 120 km/h)
- Spritmonitor.de — Fiat Ducato (diesel)
- ADAC — Zuladung von Wohnmobilen: So schnell sind sie überladen
- GOV.UK — Speed limits
- fueleconomy.gov — Which vehicles are tested (heavy-duty exemption)