EV Energy Consumption Explained: What kWh/100km Actually Tells You

EV energy consumption is measured in kWh/100km, and the number to remember is this: 13 to 16 is efficient, 17 to 19 is average for a mid-size SUV, and anything over 20 means you’re paying a meaningful premium every time you charge. It is the electric equivalent of L/100km, and it deserves the same attention you’d give a fuel figure, because it decides your running costs for the life of the car.

The catch is that there are two versions of the number, and they don’t match. The official figure on the government label is measured at the power point. The figure on your dashboard is measured at the battery. Owners regularly test drive a new EV, see 11 or 12 kWh/100km on the display against a claimed 16, and wonder if something is wrong with the car or the claim. Nothing is wrong with either. They’re measuring different things.

This guide explains what each number means, what counts as good ev energy consumption for each vehicle class, how Australia’s official figures compare with independent real-world testing, and what the differences cost you in dollars.

What Does kWh/100km Mean in an EV?

Kilowatt-hours per 100 kilometres (kWh/100km) is the amount of electrical energy an EV uses to cover 100 km. A kilowatt-hour is the standard unit on your electricity bill, so the conversion to cost is direct: consumption × your tariff = cost per 100 km.

At a typical 30 c/kWh grid rate, a 13 kWh/100km car costs $3.90 per 100 km. A 20 kWh/100km SUV costs $6.00. Drive 12,000 km a year and that gap is worth about $252 annually, before you factor in cheaper off-peak or solar charging. For the full model-by-model cost picture, see our electric car cost per km comparison.

Some brands display Wh/km instead, which is the same number multiplied by ten: 165 Wh/km equals 16.5 kWh/100km. Others show km/kWh, where higher is better. Convert everything to kWh/100km when comparing, since that’s what the official Australian figures use. Our kWh to km converter does the translation both ways.

What Is Good EV Energy Consumption?

Around 13 to 16 kWh/100km is efficient for a small or mid-size EV, and 18 to 22 is normal for a large or all-wheel-drive SUV. Based on official figures from the Australian Government’s Green Vehicle Guide as of August 2026, the classes break down like this:

Vehicle class	Efficient	Typical	Examples (official figure)
Small hatch	13–15	15–18	MG4 64 kWh: 13.0, MG4 51 kWh: 18.4
Sedan	13–15	16–17	Tesla Model 3 RWD: 13.2, Model 3 LR AWD: 16.5
Mid-size SUV	15–17	17–19	Tesla Model Y 2025: 15.3, BYD Atto 3: 14.9
Large / AWD SUV	17–19	19–22	Kia EV5 Air LR: 18.0

Two things stand out in that table. First, drivetrain matters more than size: the Tesla Model 3 RWD is rated at 13.2 kWh/100km while the dual-motor Long Range version of the same car is rated at 16.5. Adding a second motor typically costs 15 to 25 percent in efficiency.

Second, variants of one model can differ sharply. The MG4 spans 13.0 to 18.4 kWh/100km across its range on official figures, with the smallest-battery 51 kWh version, counterintuitively, the least efficient. If you’re cross-shopping variants, check the specific one, not the model’s headline number.

Why Your Dashboard Reads Lower Than the Official Figure

The official figure includes charging losses and the dashboard figure doesn’t. That single fact explains most of the gap that confuses new owners.

WLTP, the test protocol behind Australian consumption labels, runs a standardised cycle at 23°C averaging around 46 km/h, then recharges the battery from the mains and measures the energy at the wall. Everything lost between the power point and the battery, in the onboard charger, the cables, and the battery’s own charging chemistry, is counted.

The trip computer (the display in the car) only meters energy flowing out of the battery while you drive. It never sees charging losses, and depending on the brand it may also exclude energy used while parked, such as pre-conditioning or standby drain.

How big are charging losses? A 2026 ADAC laboratory study (a German motoring body test, reported by Australian outlets in August 2026) measured losses of 12.7 to 24.2 percent when trickle charging from a standard power point, but only 5.1 to 7 percent from a dedicated 7 to 22 kW wallbox. DC fast charging lands in between once battery cooling is counted. The practical lesson sits alongside the numbers: a proper wall charger doesn’t just charge faster, it wastes less of what you pay for. Our guide to choosing a home EV charger covers the options.

There’s a second reason dash readings often flatter the official number: test drives are usually short suburban loops, which is precisely where EVs excel. That deserves its own section.

City Versus Highway: The Inverse of Petrol

EVs use less energy in town than on the open road, which is the reverse of what a lifetime of petrol driving teaches. Two mechanisms drive it.

Regenerative braking converts the car’s momentum back into stored charge every time you slow down. Stop-start traffic gives it constant opportunities. RACV estimates regenerative braking contributes roughly 20 percent of an EV’s total driving range in normal use, and the share is highest in urban driving.

Aerodynamic drag rises with the square of speed. At 60 km/h it’s a minor load; at 110 km/h it dominates, and there’s little braking on a freeway for regen to claw anything back. A car showing 12 kWh/100km in the suburbs can show 17 or more at highway pace. Climate control adds further load, with heating a bigger drain than cooling. Our breakdown of real-world range loss by condition puts numbers on each factor.

This matters when reading any consumption claim, including your own dash. A figure earned in city traffic will not survive a road trip. Judge a car on mixed or highway figures if that’s how you drive.

Official Figures Versus Real-World Testing

Australia now has independent, locally measured consumption data, and it shows the official figures flatter some cars far more than others. The Australian Automobile Association’s Real-World Testing Program (realworld.org.au, funded by the federal government) drives production cars on a 93 km Geelong-area route and measures recharge energy at the wall, making its results directly comparable with the official lab numbers.

Results as of the program’s 2025-26 rounds:

Vehicle	Official (kWh/100km)	Real-world	Consumption gap
Tesla Model Y LR AWD (2024)	16.9	16.7	−1%
Tesla Model Y (2025)	15.3	14.8	−3%
Kia EV5 Air LR (2026 test)	18.0	18.5	+3%
Tesla Model 3 RWD (2024)	13.2	14.0	+6%
MG4 51 kWh (2023)	18.4	20.0	+8%
Kia EV3 (2025)	14.9	16.4	+10%
Smart #1 (2024)	17.4	20.3	+17%
BYD Atto 3 (2023)	14.9	18.0	+21%

The spread is the story. Both Tesla Model Ys actually beat their official figures on the road. The BYD Atto 3 used 21 percent more energy than its label, and its measured range fell from a claimed 480 km to 369 km. The MG4 51 kWh delivered 281 km against a claimed 405 km, a 31 percent shortfall, in AAA testing reported in December 2025.

None of this makes the worse performers bad cars. It makes their labels optimistic, which matters if you sized your budget or your charging plans around the sticker. Where AAA data exists for a car you’re considering, trust it over the lab figure.

How to Compare Consumption Between Cars Fairly

Use the official Green Vehicle Guide figure for shopping comparisons, and never compare one car’s dashboard readout with another car’s label. The official figures are imperfect, but they’re measured identically for every car, wall-to-wheels. Dash readouts are not: brands differ in what ancillary loads they count, so a displayed 14.0 in one car and 14.5 in another may not reflect a real difference at your meter.

A fair comparison process looks like this. Start with Green Vehicle Guide figures for the exact variants you’re considering. Check realworld.org.au for AAA results, and where the real-world gap is large, mentally re-rank. Then convert to dollars at your own tariff using our EV charging cost calculator, because a 2 kWh/100km difference matters far more to a 25,000 km/year driver on grid rates than to somebody charging a short commute from solar surplus.

One last calibration point for electric vehicle shoppers: efficiency differences are real money, but small ones aren’t decisive. The gap between 15 and 16 kWh/100km at 30 c/kWh over 12,000 km is $36 a year. The gap between an optimistic label and reality, as the Atto 3 and MG4 51 kWh show, can be ten times that, plus a range shortfall you live with every trip. Weight the real-world data accordingly.

Frequently Asked Questions

What is a good kWh/100km for an electric car?

For a small hatch, 13 to 16 kWh/100km is typical. Efficient sedans like the Tesla Model 3 RWD manage 13.2 kWh/100km on the official test. Mid-size SUVs run 15 to 19, and large or AWD SUVs 18 to 22. Lower is better: each kWh/100km saved is worth about $36 a year at grid rates.

Why is my EV’s dashboard consumption lower than the official figure?

The official WLTP figure is measured at the power point and includes charging losses, around 5 to 7 percent on a wallbox and more on a power point. Your trip computer only counts energy leaving the battery while driving. The dashboard tells you about your driving; the label predicts what you’ll pay at the meter.

Does the WLTP consumption figure include charging losses?

Yes. WLTP consumption is calculated from the energy needed to recharge the battery from the mains after the test cycle, so charger and conversion losses are built in. That’s the main reason a car rated at 16.5 kWh/100km can show 13 to 14 kWh/100km on its own display.

Do EVs use more energy in the city or on the highway?

On the highway. EVs are the inverse of petrol cars: stop-start city driving lets regenerative braking recover energy, while sustained 110 km/h driving fights aerodynamic drag with no regen opportunity. RACV puts regenerative braking’s contribution at roughly 20 percent of total driving range in mixed use.

How much does it cost to drive an EV 100 km in Australia?

At a 30 c/kWh grid rate, a 13 kWh/100km car costs about $3.90 per 100 km and a 20 kWh/100km SUV about $6.00. Off-peak tariffs of 15 to 22 c/kWh roughly halve that, and solar surplus charging brings it under a dollar. A petrol car at 8 L/100km and $2.00/L costs $16.