EV Charging Costs vs Petrol in NZ

Home charging an EV can cost a fraction of running a petrol car in New Zealand — but the gap depends heavily on your power plan and how much you drive.

The basic maths

A typical mid-size EV uses roughly 15–18kWh per 100km. With home electricity averaging around 28–32 cents per kWh on a standard plan, that works out to about $4.50–$5.50 per 100km. A comparable petrol car averaging 7–8 litres per 100km at around $2.75 per litre costs roughly $19–$22 per 100km. That's the headline gap: EVs typically cost around a quarter to a third as much per kilometre to run on fuel alone, before servicing differences.

A weekly example

For a commuter doing 300km a week — a fairly typical Auckland or Wellington commute plus weekend driving — the numbers look like this: an EV charged at home costs roughly $13–$17 a week in electricity, while the equivalent petrol car costs roughly $57–$66 a week in fuel. Over a year, that's a difference of somewhere around $2,300–$2,500 in fuel/power costs alone.

Off-peak plans make the gap bigger

Several NZ retailers offer EV-specific or time-of-use electricity plans with cheap overnight rates, sometimes as low as 12–15 cents per kWh between roughly midnight and 6am. Charging overnight on one of these plans can push the cost per 100km down to around $2–$3, widening the annual saving versus petrol to well over $3,000 for a typical commuter, depending on the specific plan and provider.

Public charging changes the picture

Home charging is where the savings are biggest. Public DC fast chargers from networks like ChargeNet and BP Pulse charge per kWh at rates often 2–3 times the price of home off-peak power, sometimes landing close to petrol-equivalent cost per kilometre for drivers who rely heavily on public charging rather than plugging in at home overnight. If you can't charge at home — renting, no driveway, apartment living — the EV cost advantage shrinks considerably, which is worth factoring in before assuming the savings will be as large as the headline numbers suggest.

Don't forget the other running costs

• Servicing — EVs have fewer moving parts (no oil changes, timing belts, or exhaust systems), typically saving a few hundred dollars a year in scheduled maintenance.
• Road User Charges (RUCs) — light EVs in NZ now pay RUCs similar in structure to diesel vehicles, which partially offsets the fuel savings and should be included in any real comparison.
• Tyres — EVs are heavier and can wear tyres slightly faster, a smaller but real ongoing cost.

Bottom line

For a household that can charge at home overnight and drives a typical weekly distance, an EV will usually cost somewhere between a third and a quarter of the fuel cost of an equivalent petrol car, even after accounting for RUCs. The savings shrink significantly for anyone relying mostly on public fast charging, so home charging access is the single biggest factor in whether the switch pays off financially.