Diesel has always paid road user charges. Electric vehicles started in April 2024. Petrol does not — its share is excise collected inside the pump price, which is why adding the charge to an EV and not to a petrol car is a fair comparison rather than a thumb on the scale.
The rate is flat, and that runs in a direction people do not expect:
15 kWh/100 km at 25c/kWh = 3.75c a kilometre of power
$76 per 1,000 km = 7.60c a kilometre of charge
Twice as much. On an efficient electric car the government charges more for the road than the power company charges for the power — and because the charge is flat, making the car twice as efficient does not halve the running cost. It takes about a quarter off.
No rate is frozen into this page. Every price and every charge below is a box you can edit, with a default that was true when it was written and may not be now — a rate compiled into a program is a rate that goes quietly wrong. Nothing is stored: this page has no database and no session.
The garage
That is 4.42c of electricity and 7.60c of road user charges. The diesel ute costs 26.50c, so over 12,000 km a year the gap between them is $1,737 — before anything either of them cost to buy.
What a kilometre costs
Energy first, then the road charge on top of it. On an efficient electric car the second segment is the longer one.
Petrol has no second segment because its share is already inside the $2.60 a litre above.
A year of it
| Vehicle | Energy | Road charge | To run | A year | All in, per km |
|---|---|---|---|---|---|
| The EVev | 4.42c | 7.60c | 12.02c | $3,243 | 27.02c |
| The plug-inplug-in hybrid | 9.43c | 3.80c | 13.23c | $3,387 | 28.23c |
| The petrol hatchpetrol | 19.50c | — | 19.50c | $4,140 | 34.50c |
| The diesel utediesel | 18.90c | 7.60c | 26.50c | $4,980 | 41.50c |
Against how far you drive
Every line starts at $1,800, because registration and insurance do not care whether the car moves. The slope is the running cost, and where two lines cross is where the cheaper one to run has paid back nothing at all — the purchase price is not in here.
7.60c a kilometre of charge against 4.42c of electricity. Road user charges are a flat $76 per thousand kilometres whatever the vehicle is, so on something this efficient they are the larger half of the bill — the government charges more for the road than the power company does for the power. A petrol car pays its share as excise inside the pump price instead, which is why it has no line here.
A version of The EV that used half as much would cost 9.81c a kilometre instead of 12.02c. The charge did not move, so only the energy half of the bill halved. That is worth knowing before choosing between two of these on a consumption figure: the difference on the sticker is bigger than the difference on the road.
On energy alone the cheapest to run, in order, would be The EV, The plug-in, The diesel ute, The petrol hatch. With the road charge it is The EV, The plug-in, The petrol hatch, The diesel ute. That is not an argument about whether the charge should exist — it is the only way to see how much of the answer it is carrying, which on a comparison like this one is most of it.
Diesel is $2.10 a litre against petrol's $2.60, which is the number on the forecourt. On energy alone these two land 0.60c a kilometre apart in the diesel's favour — though they are different vehicles here, so that gap is partly the cars and not only the fuel. Then the road charge adds 7.60c to the diesel and nothing to the petrol, because petrol already paid at the pump. Whatever the two cars are, the forecourt sign is not the comparison.
11.35c a kilometre on the driveway, 18.10c on a public charger — $810 a year at 12,000 km. That gap is larger than the difference between most pairs of electric cars, so whether there is a plug where the car sleeps decides more than which car it is. This page has it at 90% at home; if that is a guess, it is the guess most worth checking.
A plug-in hybrid is two vehicles, and which one you own depends entirely on how often it is actually plugged in. This page has it at 60% of kilometres on the battery. Never plugged in it is a petrol car that also pays the road charge on every kilometre, including the ones it burned petrol for — which is the one case where the charge is unambiguously working against you.
Registration, a warrant and insurance come to $1,800 whether the car moves or not, so the all-in cost per kilometre falls the further you drive: it is 48.02c at 5,000 km and 19.23c at 25,000. Two people quoting cents a kilometre at each other from different annual distances are not disagreeing about anything. Depreciation is not in that figure and is not on this page: it is a guess about a resale market, not a fact about a car.
The EV saves $1,737 a year against The diesel ute at 12,000 km. So the purchase price is the whole argument, and this page deliberately has nowhere to type it: a price is a negotiation, not a fact, and the running cost is the part that can be worked out. At 12,000 km a year, 13,817 km of driving pays back a ten-thousand-dollar difference over five years.
What it does not know
Depreciation is not here. On a newish car it is usually larger than everything on this page put together — and it is a guess about a resale market three years out, not a fact about a vehicle. Putting a made-up number next to measured ones would make the measured ones look like guesses too.
Neither is the purchase price. Deliberately: a price is a negotiation, and the running cost is the part that can be worked out. What the page gives instead is how many kilometres it takes to pay back a difference, which is the same question with the guess taken out of it.
Servicing and tyres are in nobody's column. They differ by drivetrain — an EV has no oil and no cambelt, and heavier cars eat tyres faster — and by enough that a confident number would be an invented one.
The consumption figures are whatever you typed. A manufacturer's number is a laboratory number; a real one is fifteen to thirty percent worse in town, and an EV's is worse again in winter and on the open road. The comparison survives that better than the absolute figures do, because it moves both.
Road user charges are paid in advance, in blocks. The arithmetic here spreads them evenly over the kilometres, which is what they cost; it is not what the payments look like, and a bill for a thousand kilometres you have not driven yet is a real cashflow thing that a cents-a-kilometre figure hides.
It has no view on the charge itself. The rate is an input. What a flat per-kilometre charge does to a comparison between an efficient vehicle and a thirsty one is arithmetic, and it is the whole of what this page has to say about it.