EV vs Petrol Calculator: Compare running costs
Use the EV running cost calculator to compare costs between a petrol, diesel, hybrid car, and an EV.
What will make an EV cheaper to run?
- Charge at home as much as possible, preferably overnight, on off-peak rates.
- Shop around for the best power company for you.
- Consider rooftop solar panels (the combination of rooftop solar + EV can considerably lower household costs).
How much is RUC?
Road User Charges (RUC) are levied on some vehicles to contribute toward road maintenance.
Light diesel vehicles and fully electric vehicles pay $76 (incl. GST) per 1000 km of travel. Plug-in hybrid EVs pay $38 / 1000 km. In addition, an administration fee ($12.44 – $13.71) is required at purchase.
Hybrid and petrol vehicles contribute via Fuel Excise Duty, which is incorporated into petrol price, at 0.805 cents per litre (incl. GST).
The mix of the two systems means that low-consumption petrol vehicles contribute the least.
Any petrol vehicle (including hybrids) that consumes under 9.5L / 100 km contributes less than the equivalent RUC amount.
Why is there no depreciation and insurance?
These two factors are highly changeable and are not necessarily correlated with a vehicles level of electrification.
- Vehicle depreciation can be brand and model-specific and varies greatly depending on market conditions.
- Insurance premiums are based on the driver risk, location, sum insured, vehicle performance and risk, and materials used.
Insurance: Aqua vs Kona Electric vs Tesla
Here’s a 2025 insurance quote, all variables identical, only difference is vehicle model and sum insured:
2020 Toyota Aqua Hybrid, insured for $18,000 – quote is $1,856 per year.
2019 Hyundai Kona Electric, insured for $30,000 – quote is $1,200 per year.
2020 Tesla Model 3 (SR), insured for $35,000 – quote is $1,619 per year.
Why? The Aqua has higher risk of theft. Despite the Aqua’s low fuel usage (4.8L / 100 km) – it’s more expensive to run.
Are some EVs cheaper to run than other EVs?
Yes. There is considerable variation in the efficiency of different EVs.
How are maintenance and service costs calculated?
The vehicle’s lifetime costs are applied at a per-kilometre rate (no specific adjustments per model). For example, the new tyres you need after 40,000 km might cost $1,000. If you drive 10,000 km per year, that’s $250 / year for tyres.
While it’s hard to generalise, some good data sources exist (see references).
What are the differences in maintenance between ICE and EV?
All vehicles: Tyre rotation, wiper blades, cabin air filter, multi-point inspection, tyre replacement, brake fluid, brake pads, starter battery (12v).
Additional costs for combustion vehicles (including hybrids): Oil change, oil filter change, engine air filter, spark plugs, transmission service, timing (cam) belt, accessory belt(s), engine coolant, and fuel filter.
Variations for hybrids: The maintenance schedule for some items are different: engine air filter, spark plugs, brake pads, etc., can be checked/changed less frequently than a petrol/diesel drivetrain.
Brake pads are changed even more infrequently in a fully electric car due to superior regen.
What about battery replacement costs?
Not included as it’s extremely unlikely the battery will need replacing. However, there may be exceptions with some old EVs.
How long will an EV battery last?
It’s often said that an EV battery will outlast the vehicle. But how old can a vehicle get?
In NZ, the oldest EVs are from 2012. These vehicles (24 kWh Nissan Leafs) have suffered the worst battery degradation of all EVs. This means their range gets shorter until they are no longer viable as vehicles. Anecdotally, it’s only when the range becomes untenable that owners consider replacing the battery.
Newer EVs are not showing near the same level of degradation and have larger, superior batteries with longer ranges, making it very unlikely that the batteries will ever need replacing.
The reality is that almost all EV batteries are still in cars. We won’t know precisely how long a battery will last until another ten years.
Based on present data, there’s no need to consider battery replacement costs in EV expenses.
See the deep dive: When will your battery need replacing?
Want to calculate Total Cost of Ownership?
Total Cost of Ownership considers a vehicle’s purchase price, finance cost, and running costs.
See the TCO calculator from Genless (EECA).
End Notes
- Typical (generic) EV cost estimate is based on the averaged WLTP consumption values of the five most popular EVs in NZ. Otherwise WLTP consumption rating for each specific model is used..
- The WLTP measures recharged electric energy from the mains and applies that to the vehicle’s range (Wh/km).
- Nissan Leaf battery degradation – extensive data at Flipthefleet.
- Tesla Model 3 – battery degradation tracking and data.
- Recurrent – how long do EV batteries last (data-driven).
- Burnham, A., Gohlke, D., Rush, L., Stephens, T., Zhou, Y., Delucchi, M. A., … & Boloor, M. (2021). Comprehensive total cost of ownership quantification for vehicles with different size classes and powertrains (No. ANL/ESD-21/4). Argonne National Lab.(ANL), Argonne, IL (United States).
- National Land Transport Fund (aka Petrol Excise Duty) – current rates.
- Difference between Petrol Excise Duty and RUC – Ministry of Transport
