Charging a battery is a lot cheaper than paying for gas at the pump. But now that electric vehicle (EV) and plug-in hybrid (PHEV) owners have to pay Road User Charges (RUCs), how much cheaper is it to hit the road powered by electricity than old-fashioned gasoline? Canstar Blue compares the average running costs of the country’s three most popular EVs, with those of three comparative plug-in hybrid and petrol (ICE) models.
→ Related article: What are Road User Charges
Electric vehicle running costs
Let’s start with the running costs of last year’s top-three selling EVs. For this comparison we’ve stuck to the basic models of each EV, and used the national average electricity price of 33.74c per kWh. Do note that electricity prices vary, so check your individual plan to find your cost per kWh.
We’ve also included the price with and without (RUCs). For EVs, the RUC is $76 per 1000km unit ($7.60 per 100km).
| Car model | Cost | kWh per 100km | Cost per 100km |
| MG 4 Excite 51 | $46,990 | 18.4kWh | $6.21 ($13.81 with RUC) |
| BYD Atto 3 (50kWh) | $56,990 | 16kWh | $5.40 ($13 with RUC) |
| Tesla Model Y (Real Wheel Drive) |
$67,900 | 15.7kWh | $5.30 ($12.90 with RUC) |
Petrol vehicle running costs
For this comparison we’ve picked three popular petrol cars that also have comparative PHEV models. To be honest, when we started our research, we didn’t think it would be so hard to find apples-for-apples comparisons of petrol cars and their PHEV comparisons. However, so many manufacturers now only produce models that are either PHEVs or mild-hybrids (MHEVs) that finding a single car model that comes in both ICE and PHEV versions proved difficult. This is why there are two Mitsubishi vehicles on our list.
For our comparison, we’ve used an average unleaded 91 price of $2.77 per litre, as sourced from Gaspy on 22/03/24.
| Car model | Cost | l per 100km | Cost per 100km |
| Mitsubishi Outlander LS 4WD | $44,990 | 8.7l | $24.10 |
| Mitsubishi Eclipse Cross XLS AWD |
$39,990 | 8.6l | $23.82 |
| MG HS Vibe | $33,990 | 7.3l | $20.22 |
Plug-in hybrid vehicle running costs
For PHEVs, we’ve again used an unleaded 91 price of $2.77 per litre. Of course, as PHEVs also have batteries, there are electricity costs associated with their use. However, these costs are minimal and difficult to calculate, so we are only focusing on petrol costs for our price comparison.
As PHEV users also pay for petrol, the RUC rate for PHEVs is lower: $38 per 1000km unit ($3.80 per 100km).
| Car model | Cost | Combined per 100km | Cost per 100km |
| Mitsubishi Eclipse Cross PHEV XLS |
$52,990 | 1.9l | $5.26 ($9.06 with RUC) |
| MG HS Excite PHEV | $50,990 | 1.7l | $4.70 ($8.50 with RUC) |
| Mitsubishi Outlander LS PHEV | $62,990 | 1.6l | $4.43 ($8.23 with RUC) |
Overall Cost Table
The table is ordered cheapest to most expensive to run:
| Car model | Cost | Cost per 100km | Cost per 14,000km/year |
| Mitsubishi Outlander LS PHEV | $62,990 | $8.23 | $1152 |
| MG HS Excite PHEV | $50,990 | $8.50 | $1190 |
| Mitsubishi Eclipse Cross PHEV XLS |
$52,990 | $9.06 | $1268 |
| Tesla Model Y | $67,900 | $12.90 | $1806 |
| BYD Atto 3 | $56,990 | $13 | $1820 |
| MG 4 Excite 51 | $46,990 | $13.81 | $1933 |
| MG HS Vibe | $33,990 | $20.22 | $2830 |
| Mitsubishi Eclipse Cross XLS AWD |
$39,990 | $23.82 | $3334 |
| Mitsubishi Outlander LS 4WD | $44,990 | $24.10 | $4,097 |
While it’s no surprise that EVs are cheaper to run than petrol vehicles, the surprise is how cheap PHEVs are to run. Those above are, on average, $4.67 per 100km cheaper to fuel than the EVs, which is around 33%.
Even when you take into consideration that PHEVs require some power, a PHEV is still going to work out cheaper to run than an EV.
This is because while EVs are cheap to charge – especially if you’re on a power plan that offers cheaper/free off-peak power – any savings are offset by their higher RUCs.
Also, when calculating the savings to be made by going electric, you have to take into consideration the higher cost of EVs, compared to ICE vehicles. In our comparison, the EVs and PHEVS are about $15,000 more expensive, on average, than our petrol models.
If we look at only the Mitsubishi Eclipse Cross PHEV XLS vs Mitsubishi Eclipse Cross XLS AWD, there’s a $13,000 price difference. At 14,000km per year, that means it will take you around 6 years and 4 months of fuel savings to make up the difference in price!
For the Cheapest EV Charging Compare Power Companies
As we mention above, if you’re looking for the cheapest way to charge your EV, choosing a power company that offers great off-peak power rates is essential. And a great way to start your research is by checking out Canstar’s latest Star Ratings awards. Based on the satisfaction ratings of real-life Kiwi electricity consumers, they rate NZ power companies for customer satisfaction and value for money. See the table below for some of the results, or click on the button below for the full results of our survey.
Canstar Blue’s latest review of NZ power companies compares them on customer satisfaction. The table below is an abridged version of our full results, available here.
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Canstar Blue NZ Research finalised in April 2023, published in June 2023.
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About the editor of this page
This report was written by Canstar’s Editor, Bruce Pitchers. Bruce has three decades’ experience as a journalist and has worked for major media companies in the UK and Australasia, including ACP, Bauer Media Group, Fairfax, Pacific Magazines, News Corp and TVNZ. Prior to Canstar, he worked as a freelancer, including for The Australian Financial Review, the NZ Financial Markets Authority, and for real estate companies on both sides of the Tasman.
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