Owners of battery electric vehicles now pay road user charges of $76 per 1000 kilometres, the same rate charged to diesel vehicles. The change, introduced this month, has pushed up the day-to-day running cost for many EV drivers, but how much it matters depends on where and how drivers charge their cars and whether other incentives remain in place.
What the new charges mean for typical trips
Analysts and motoring groups who model running costs say the effect is significant but not decisive for most privately owned EVs. An illustrative example commonly used is a 170-kilometre return trip between a regional town and Wellington. For a driver who can charge at home during off-peak hours and whose electricity tariff is modest, the energy cost for that trip has risen from a few dollars to the mid-teens once the road user charge is added.
By comparison, the same trip in a petrol car — using current average petrol prices — costs substantially more. That means for many routine trips an EV charged at home remains cheaper to operate than a comparable petrol vehicle even after road user charges are applied. The exact saving varies with electricity prices, vehicle efficiency and real-world driving conditions.
However, the cost picture changes on the road. If a driver must rely on commercial public fast chargers rather than home overnight charging, the energy bill for a long trip can rise markedly. In that scenario, the combined cost of commercial charging plus the $76 per 1000 kilometres road user charge can put an EV’s total trip cost in line with or similar to a petrol vehicle’s cost for the same distance.
The broader numbers: 1000-kilometre comparisons
Across wider calculations submitted to policymakers, estimates have been produced for standardised 1000-kilometre comparisons. For EVs charged at home, the average running cost was calculated at about $128 per 1000 kilometres. Using the current typical petrol price of roughly $2.95 per litre, a petrol car would average around $236 per 1000 kilometres for fuel alone. Diesel, meanwhile, works out even higher in these comparisons, at about $312 per 1000 kilometres.
