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Motorhome MPG: Real-World Fuel Economy by Van Type

Last updated: 28 October 2026 · Kervana team

Short answer

In owners' real-world reports, most van conversions return 30–35 mpg, a 6-metre coachbuilt motorhome around 28–32 mpg, and larger motorhomes over 3,500 kg about 25 mpg. Speed, load, a roof box and the wind can move these by several mpg either way.

Official figures are usually optimistic: owners typically get 70–90% of the official mpg, and less in heavier, automatic or four-wheel-drive versions.

Real-world mpg by base vehicle

Owner-submitted averages (UK mpg, imperial gallons) from the Honest John Real MPG database. These are mostly for the vans themselves; a converted campervan with a pop-top, furniture and water on board will usually sit at the lower end.

Base vehicleOwner-reported averageRange across enginesTypical use
Volkswagen T6 Transporter (2015–2025)34.7 mpg27–40 mpgCompact campervans
Ford Transit Custom (2013–2024)about 31 mpg30–35 mpgCompact campervans
Fiat Ducato (2006 on)31.1 mpg28–36 mpgMost UK motorhomes and van conversions
Ford Transit (2014 on), 2.2 TDCi 15525.6 mpg—Larger van conversions
Mercedes Sprinter (2013–2018)25–29 mpg25–29 mpgLarger van conversions and coachbuilts

The Peugeot Boxer and Citroën Relay share the Ducato's body but use their own engines, so treat the Ducato figures only as a rough guide for them.

Real-world mpg by motorhome size

Owners' reports in the Caravan and Motorhome Club community line up with the database figures:

TypeTypical real-world mpgL/100 km
Van conversion up to about 6 m30–35 mpg9.4–8.1
Coachbuilt around 6 m, 3,500 kg28–32 mpg10.1–8.8
Larger motorhome over 6 m and 3,500 kgabout 25 mpgabout 11.3

To convert, use L/100 km = 282.5 ÷ mpg.

What lowers your mpg

  • Speed. The Department for Transport puts the extra fuel at about 10% at 70 mph compared with 60 mph, and about 25% at 85 mph compared with 70 mph, for a car. A tall, boxy motorhome pushes more air, so it pays at least as much for every extra mph. Most cars are most efficient at around 45–50 mph.
  • Speed limits help. Motorhomes over 3.05 tonnes unladen are limited to 50 mph on single carriageways and 60 mph on dual carriageways (70 mph on motorways). Lighter ones follow car limits.
  • Roof boxes and racks. At motorway speeds a roof box can raise fuel use by around 25% (Department for Transport); Energy Saving Trust figures cited by the RAC put the extra drag at 39% for a roof box and 16% for an empty roof rack at 75 mph.
  • Weight. Full water tanks, a full gas locker and everything packed "just in case" all add up. Travel with the water you need, not a full tank, where you can fill up again easily.
  • Tyre pressure. Under-inflated tyres raise consumption and wear. Check them cold, to the pressures for a loaded vehicle in the handbook.
  • Wind, hills and short hops. A headwind on the motorway, a day in the hills or a cold engine on short trips all noticeably lower your mpg.
  • Idling. Running the engine to charge batteries or warm the van uses fuel without moving you.

Measure your own mpg

The dashboard figure is often a little optimistic. The fill-to-fill method is more reliable:

  1. Fill to the brim and note the odometer.
  2. At the next fill-up, fill to the brim again and note the litres and the odometer.
  3. mpg = miles driven ÷ (litres ÷ 4.546).

Average three or four fills before you trust the figure. Then turn it into money with the table in campervan fuel cost per mile: at the October 2026 UK diesel average (about 199p a litre), 25 mpg costs about 36p a mile and 35 mpg about 26p.

If you log every fill-up with the litres and the odometer, Kervana works out your average consumption (mpg or L/100 km) for you. See how to track campervan expenses for what else is worth recording.

Sources

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