TL;DR: Charge at home and a mainstream EV runs about $3.52–5.94 per 100km, against $13.04 for petrol and $12.77 for diesel right now. Rely on public fast-charging and the gap collapses: at worst it’s $12.60, which only beats petrol because petrol is sitting near its cycle peak this week. At the trough three weeks back, petrol was $11.39, cheaper than worst-case public charging. The plug wins big when it’s your plug, and it’s a coin-flip when it isn’t.
Every second driveway in my estate has an EV in it now, and the question at the basketball sidelines is always the same: is it actually cheaper, or did we just buy the story? So I ran the maths the way I’d want it run for me. Cents per 100km, nothing airbrushed out, petrol quoted both where it actually sits today and where it sat at the bottom of the cycle.
The claim
An EV is cheaper to run than petrol or diesel in Queensland.
What we checked
The fuel side is our live Brisbane-metro prices, right now, to 19 July 2026, from the Queensland Government feed, the price each station reported charging, not a driver’s guess at the bowser. The current median for ULP 91 is 173.9 c/L across 440 stations; the diesel 2+10 family sits at 212.9 c/L across 473 stations. At 7.5 L/100km that’s $13.04 per 100km for petrol; at 6.0 L/100km, $12.77 for diesel.
The electricity side is not in our feed, so I flag it plainly: these are published AU retail-tariff and consumption ranges for a typical mainstream EV, not a measurement of any one car. Home charging at $0.22–0.33/kWh and 16–18 kWh/100km lands the EV at $3.52–5.94 per 100km. Public DC fast-charging at $0.55–0.70/kWh lands it at $8.80–12.60.
What the data shows
Two different worlds, depending on where you plug in.
If you charge at home, it isn’t close. Around $3.52–5.94 per 100km against $12.77 diesel and $13.04 petrol, a third to a half the energy cost. That’s real, and it’s the version EV owners quote at barbecues.
If you can’t charge at home and live on public DC, the gap collapses. At the top end, 18 kWh/100km on a $0.70/kWh charger, you’re at $12.60 per 100km. Right now that edges out both petrol ($13.04) and diesel ($12.77), but only because petrol is sitting near its cycle peak this week. The last trough, on 29 June, was 151.9 c/L, which is $11.39 per 100km, cheaper than worst-case public charging. Do the break-even and petrol undercuts that $12.60 worst case whenever ULP is under 168.0 c/L, which is most of the cycle. So a driver on public chargers only, filling against a normal-to-cheap petrol week, may not save a cent on energy.
The verdict
EV wins big if the charger is yours. It’s a coin-flip, and sometimes a loss, if you’re renting turns at a public bay, because worst-case public charging only beats petrol in the week petrol is peaking. The deciding variable isn’t the badge on the car; it’s whether you’ve got a driveway and an off-peak tariff.
So what
Before you switch to save on fuel, answer one question first: can I charge at home overnight? If yes, the energy savings are large and durable, bank on the $3.52–5.94 range. If no, run your own numbers on the public chargers you’d actually use, because the plug premium can erase the whole advantage, and don’t let a comparison against this week’s peak petrol flatter it.
Our Brisbane median is riding near a cycle peak right now at 173.9 c/L; 20 days ago, on 29 June, it troughed 22 cents lower at 151.9, and a driver who fills only at the bottom pays closer to $11.39/100km. You can watch the cycle and catch that trough yourself at fill.pinly.com.au.
One more thing the per-100km view corrects: diesel trades above petrol at the pump (212.9 vs 173.9), but its lower consumption makes it a touch cheaper per 100km. “Diesel’s dearer” is misleading once you measure by distance instead of by litre.
The honest limit
This is running-fuel-cost only. It excludes purchase price, depreciation, servicing, insurance, tyres, rego, charger install and battery wear, where EV and ICE differ a lot and can flip the total-cost verdict either way. QLD’s EV rebates help the switch case; a future road-user charge on EVs would erode this per-100km advantage. Neither is in these energy-only numbers.
A few straight caveats on the figures. The petrol and diesel c/L are from our feed; the EV and electricity numbers are external generic AU ranges, cited not measured, and not tied to any named car. Consumption rates (7.5 L/100km petrol, 6.0 diesel, 16–18 kWh/100km EV) are stated assumptions; real-world figures vary by vehicle, driving and climate. The diesel-family median blends bowser diesel (212.9) and premium diesel (215.9) to 212.9 c/L. A handful of stations (10 of 440 ULP, 4 of 473 diesel) last reported more than 14 days ago and are carried forward, which doesn’t move the median. And today’s petrol median sits near the top of the Brisbane cycle, so quoting it flatters the EV case, which is exactly why the trough figure is in here too.