Buyers fixate on the headline range figure on an EV, then get confused when the car never seems to cover it. Sellers and media quote a per-kilometre running cost that skips half the equation. Neither is dishonest; both are just incomplete. The honest version factors in real conditions and the full cost picture.
What real range looks like in NZ
The advertised range of an EV is generally measured in ideal conditions: flat ground, moderate temperature, steady speed. Real driving is different, and New Zealand is a good example of why the number falls:
- Hills. Range is easily shortened by sustained climbs, and much of New Zealand is not flat.
- Open-road speed. Steady high-speed driving uses more energy per kilometre than city stop-start at lower speeds.
- Cold weather. Cold reduces range because batteries are less efficient at low temperatures and you may also use heating.
- Load and driving style. A loaded car and heavy acceleration or braking both use more energy.
The practical result is that the honest daily range is usually meaningfully below the headline, and the gap can be at its largest on exactly the long rural trips where range matters most. Expect the real figure, and treat any plan that depends on the full advertised number as optimistic.
When range should change your decision
Range does not matter equally for everyone, which is the part manufacturers do not want to talk about. If your driving is almost entirely short, day-to-day trips well within the real-world range and you can charge at home, the headline range barely matters at all. You are never near the edge.
It matters if you regularly do long runs outside the cities, because charge points are only well covered across some areas of New Zealand so far. On those routes, the real range and the spacing of public chargers decide whether the trip is comfortable or stressful. Match the car to your actual longest regular trips, not the most impressive number on the brochure.
Cost per kilometre: the fair comparison
The honest way to compare running cost is per kilometre, for both cars, using your real driving and real local prices:
- For the EV. Start with your cost per unit of electricity, add some allowance for charging inefficiency, then divide by the kilometres the car actually gets per unit at your driving conditions. Our guide to charging an EV covers the charging-cost side of that equation.
- For the petrol car. Divide the price per litre of fuel by the kilometres the car gets per litre.
That gives you two comparable per-kilometre fuel numbers. In most New Zealand cases the EVs number comes out lower, which is why they are described as cheaper to run. But per-kilometre fuel is not the whole story: an EV can also mean different servicing costs, and the bigger numbers of purchase price and depreciation sit on top. Our guide to buying an EV puts those larger costs into the total picture.
Do not fall for a per-kilometre figure that only multiplies fuel price by fuel economy. A complete comparison also includes how fast the car uses energy in your conditions, the price of the electricity or fuel at your actual pumps and charge points, and the depreciation, insurance and servicing across the years you will own it. Half the equation always flatters one car.
Putting it together for your situation
Turn it into a decision you can trust with three steps:
- Measure your driving. Your annual kilometres and your longest regular trip are the two inputs that decide both range fit and running cost.
- Price your real charging. Work out where you will actually charge and at what price per unit, not the best case you hope for.
- Compare total cost over time. Add purchase price, depreciation, and running costs for both the EV and the petrol alternative, and compare those totals.
Range and running cost are not marketing numbers to impress you; they are inputs to a total-cost comparison for your specific driving. Do the per-kilometre math honestly, factor in where range genuinely limits you, and pair it all with the charging and buying guidance in this category.
Real EV range is lower than advertised because of hills, speed, cold and load, and for most owners that matters little. What always matters is the fair cost-per-kilometre comparison against petrol, done with your real charging and fuel costs, as part of the full cost of ownership.