How we test EV running costs

Our test programme measures every charge and every kilometre over six weeks and at least 2,000 km. The published record connects electricity bought, distance driven and the amount paid. A planned test starts when the car is delivered. Its log identifies the vehicle and lender, then records the actual dates as the work begins.

What we measure

The charge log is the working record for the test. A session includes the odometer reading, distance since the previous recorded charge, energy added and charge level at each end. We retain the source receipt or meter record for checking the published row. A published specification remains labelled as a specification throughout the test. Findings from the test come from its recorded measurements.

Home charging

We record kilowatt-hours from the charger's own meter for every home session. Each week, we cross-check that record against smart meter interval data supplied by the electricity retailer. The charger record identifies charging energy; the household meter helps check that the timing and amount are consistent. Any difference is investigated before the affected summary is published.

We price the energy at the actual electricity plan rate paid during that session. The record states the plan name and date, including the applicable charging window. When rates change during a test, each session keeps its own rate. An existing household daily supply charge is recorded separately from the energy calculation so a charging session is not assigned the whole household bill.

Public charging

Every public session uses the network's receipt for kilowatt-hours and the amount paid. We record the network, named site, peak power observed and elapsed time from start to stop. Separate connection, parking and idle charges stay identifiable in the supporting receipt. A free session retains its receipt or operator evidence and a recorded zero cost.

The public rate is the rate that applied to that session, including the payment route or membership used. A dated receipt records that purchase. Other chargers on the same network retain their own site prices. The national public-price register remains a separate source sample with its own dates and conditions.

Driving records

We record the odometer at every charge and tag each leg as city, highway or mixed. The log includes outside temperature from the nearest Bureau of Meteorology station, the air conditioning setting and passengers. Supporting notes identify the weather station and observation time. Traffic or a change to the planned route is recorded with the affected leg so it can be interpreted alongside its energy use.

Fixed routes

The city loop runs from Bondi Junction through Sydney CBD and Mascot, returning to Bondi Junction. It is planned at about 30 km and is driven three times a week. The highway loop follows the M1 Pacific Motorway from Wahroonga to Kariong and back, planned at about 100 km. It is driven once a week, using the posted 110 km/h limit where it applies and conditions permit.

Actual distance comes from the odometer for that drive. The planned route lengths are not substituted for measured kilometres. Both loops stay identified in the log, while other driving is retained under the appropriate leg type. This keeps normal use in the record without treating it as another repeat of a fixed route.

What we publish

Wall-to-wheel consumption is charged kilowatt-hours divided by recorded kilometres, expressed as kWh/100 km. Charging losses are already included in the metered energy. We also publish the car's own displayed kWh/100 km separately. The two measurements have different boundaries and remain separate columns.

City and highway range use verified usable battery capacity divided by measured consumption for the relevant legs. Published capacity without a usable qualification is not silently converted into usable capacity. Cost per 100 km uses the recorded amount paid divided by distance. Weekly cost applies that measured cost per kilometre to 250 km. The petrol SUV comparison uses the same distance, the stated SUV consumption preset and the ACCC Sydney petrol observation for that week.

Publication schedule

Each charge is added to the downloadable CSV within 48 hours. A weekly summary is updated every Monday. Summary figures begin after seven recorded days, with measured distance for every included charge. The final report goes live within seven days of the car being returned. Readers can download the underlying rows and reproduce each total using the published method.

Independence

The test terms provide for a car lent by the maker for the test period, with no payment made in either direction. The maker does not see or approve findings before publication. The loan is disclosed on the test page and in every CSV row. Factual errors are corrected within 48 hours, with a dated entry on Changes.

Data licence

Our original measurements are published under CC BY 4.0, the same licence used for our own data. Attribute Cost to Charge and link to the relevant test log when reusing them. Third-party specifications and receipts retain their original source conditions. Calculator formulas and the source register explain the reference figures used alongside a test.