EV Running Cost Calculator

Calculate the running cost of an existing Internal Combustion Engine (ICE) car with a fully electric vehicle.

I travel this much

My petrol or diesel car uses this much fuel

litres/100 km

Not sure? Search by plate

I pay this much for fuel

per litre

I pay this much for electricity

cents/kWh

I want to compare with this EV

Options

For some of my travel, I'll use a public charger

0 km / year
cents/kWh

Why is there no depreciation and insurance?

  • Vehicle depreciation can be brand and model-specific, and there is not necessarily a clear distinction between ICE and EVs.
  • Insurance premiums are typically based on the driver profile and the value and performance of a vehicle – regardless of its level of electrification.

How much is RUC?

Road User Charges (RUC) are levied on some vehicles to help contribute toward road upkeep.

Light diesel vehicles pay $76 (incl. GST) per 1000 km of travel. From 1 April 2024, the same rate will be applied to fully electric vehicles. Plug-in hybrid EVs will have a rate of $53 / 1000 km. In addition, an administration fee ($12.44 – $13.71) is required at purchase.

Non-RUC vehicles contribute financially via Fuel Excise Duty incorporated in petrol prices – 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 that consumes under 9.4L / 100 km contributes less than the equivalent RUC amount.

How is EV electricity cost calculated?

The calculator uses the WLTP consumption rating for each EV.

The WLTP measures recharged electric energy from the mains and applies that to the vehicle’s range. This provides an estimate in Wh/km.

Are some EVs cheaper to run than other EVs?

Yes. There is considerable variation in the efficiency of different EVs. See the most efficient EVs.

What will make an EV cheaper to run?

  • Charge at home as much as possible.
  • Rooftop solar panels – provided the car can be plugged in for some of the daytime, costs can be minimal (particularly during summer).
  • Look carefully at what power company will work best for you.

What power company is the cheapest?

We currently use Octopus Energy – due to the high solar buyback, and very low overnight rates. If you want to support EVDB, and get a $50 credit, here’s a referral link: https://octopusenergy.nz/share/best-owl-61

However, there are numerous options, and prices vary depending on where you live.

— Thanks, James

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 sources of data 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: In hybrids, the maintenance schedule for some items is 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 it’s no longer viable as a vehicle. 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 range making it very unlikely that the batteries will ever need replacing.

What we know so far: 10-year-old Nissan Leafs with small batteries without active thermal management, and early battery chemistries degrade over time until (potentially) unviable.

It’s not the case for all of them (some 10-year-old Leafs still have 70% state of health).

We also know that Tesla Model 3s, having done over 120,000 km, still have 90% capacity.

The reality is that almost all EV batteries are still in the cars. Until another ten years, we won’t know precisely how long a battery will last.

Therefore, based on current data, it seems imprudent to factor battery replacement costs into BEV running costs.

I want to calculate the 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.

References