NZ motorhomes are almost all diesel-powered Fiat Ducato, Mercedes Sprinter or Toyota Hiace chassis. Diesel pricing in NZ is roughly NZ$1.80-2.10 per litre in mid-2026; petrol is NZ$2.60-2.90 per litre. The bigger cost factor for diesel vehicles is Road User Charges (RUC), which most rental fleets pre-pay and bundle into the daily rate — confirm this on the quote before assuming you'll pay it at pump prices.
Real-world fuel economy by vehicle class
2-berth diesel campervan (Hiace-based, ~3 tonnes): 9-11 L/100km. 2-berth diesel motorhome (Ducato-based, ~3.5 tonnes): 11-13 L/100km. 4-berth diesel motorhome (Ducato or Sprinter, ~3.5-4 tonnes): 12-15 L/100km. 6-berth (Ducato-based, ~4-4.5 tonnes): 14-17 L/100km. Mountain passes (Crown Range, Haast, Lewis) and West Coast headwinds add 15-25%.
How to estimate fuel cost for a route
Take the route distance in km, multiply by L/100km for your vehicle class (use 13 if uncertain), then by NZ$2.00 per litre. South Island 14-day loop (2,200 km × 12 / 100 × NZ$2.00) is roughly NZ$528. Auckland to Queenstown one-way (2,600 km × 13 / 100 × NZ$2.00) is roughly NZ$676. Add NZ$1-2 per litre to those numbers if your vehicle rents at "diesel + RUC at pickup" rather than RUC-included.
Where fuel costs spike
Fuel is most expensive on the West Coast (Franz Josef, Haast) and in Fiordland — sometimes NZ$0.20-0.30 per litre above Christchurch prices. Fill up in Greymouth, Wanaka or Te Anau before pushing into the remote stretches. Most North Island routes have fuel at or near State Highway 1 prices.
Note on prices. NZD ranges above are mid-2026 estimates from current rental fleet quotes and published holiday-park rates. Peak summer (mid-December through January) sits at the top of each range or above; shoulder season (March-May, October-November) sits at the bottom. We'll confirm live numbers for your dates when you send us a trip outline.