Prices: week to 25 Sep 2026
Fuel cost calculator
Fifty litres of 91 cost $167.26 at this week's national average, and fifty of diesel $154.06 before road user charges.
Trip or tank
What the calculator assumes
Prices start at the national average for the week to 25 September 2026: 334.5c for 91, 348.6c for 95 and 308.1c for diesel. Type the price on the board in front of you to replace them. For diesel the trip total adds road user charges at $76 per 1,000 km, the light vehicle rate, because a diesel driver owes that on every kilometre whether or not it shows at the pump.
In tank mode the docket shows what each 10c a litre is worth on a fill and how much of the bill is GST. A 650 km run at 8.5 L/100 km, about Auckland to Wellington, is the starting example.
Common trips at this week's prices
| Trip | Distance | Petrol car, 8.5 L/100 km | Diesel car, 7 L/100 km + RUC |
|---|---|---|---|
| Auckland to Wellington | 640 km | $181.98 | $186.68 |
| Christchurch to Queenstown | 480 km | $136.48 | $140.01 |
| Wellington to Napier | 320 km | $90.99 | $93.34 |
| Auckland to Tauranga | 205 km | $58.29 | $59.80 |
| Christchurch to Dunedin | 360 km | $102.36 | $105.01 |
Getting a better number
Fuel use on the open road is usually lower than the figure on a window sticker in town, and a loaded ute or a campervan uses far more. Pump prices also vary by town; the gate behind each region is on where the gate price is lowest. If the trip is in a diesel, RUC rates and calculator explains the RUC line.
Straight answers
How much does it cost to fill a tank in NZ?
A 55-litre tank of 91 costs about $183.99 at the national average of 334.5c (week to 25 September 2026).
How much is petrol from Auckland to Wellington?
About $181.98 one way in a car using 8.5 L/100 km at this week's average.