EV vs Petrol Running Costs Guide
🔋 Comparing EV and Petrol Costs
Electric vehicles are often cheaper to run per kilometre than petrol cars, but the full picture includes road user charges, maintenance, depreciation and the purchase price. To compare fairly you need to look at total cost of ownership, not just the cost to "fill up". This guide explains the pieces that differ between an EV and a petrol car so you can weigh them up for your own driving. It is about the concepts; actual prices change with fuel, power and RUC rates.
Energy vs Fuel
The headline advantage of an EV is the cost to move it. Electricity to charge an EV, particularly overnight at home on a cheap rate, usually costs much less per kilometre than petrol. Public fast charging is dearer, so where and how you charge matters a lot. A petrol car's cost per kilometre depends on fuel price and the car's efficiency.
The Moving Cost:
- EV at home off-peak: the cheapest way to power a car per kilometre
- EV on public fast chargers: much dearer, can approach petrol cost per km
- Petrol: cost per km set by fuel price and the car's litres per 100km
📝 The Other Costs That Matter
Road User Charges on EVs
EVs now pay road user charges by distance, just as diesel vehicles do, because they do not buy petrol with its road-funding excise. RUC is a real running cost for an EV that did not exist for early adopters, and it closes part of the energy-cost advantage. A petrol car pays its road contribution through excise at the pump instead, so neither is "free" of road funding.
Costs Beyond Energy:
- Road user charges (EV): paid by distance, a genuine running cost
- Maintenance: usually lower for an EV (no oil, fewer moving parts), but tyres can wear faster
- Depreciation: varies by model; can be a large hidden cost either way
- Purchase price: EVs can cost more upfront, affecting the total
Total Cost of Ownership
The fair comparison adds everything up over the years you will own the car and the distance you drive: purchase price, energy or fuel, RUC (for the EV) or excise (in the petrol price), maintenance, insurance and depreciation. Only then can you say which is cheaper for you. The answer depends heavily on how much you drive and whether you can charge at home.
The more you drive and the more you can charge cheaply at home, the more an EV's low energy cost outweighs its higher purchase price and RUC. A low-mileage driver, or one reliant on public charging, may find the gap small. Match the comparison to your real driving.
Don't Forget the Non-Cost Factors
Beyond dollars, EVs are quiet, have instant torque, and produce no tailpipe emissions, while petrol cars have longer range and faster refuelling. These matter to the decision even though they are not in the running-cost sum. Be clear about which factors are financial and which are about how you want to drive.
🤔 Common Misunderstandings About EV vs Petrol Costs
Misconception 1: "EVs are basically free to run"
Reality: EV energy is cheap, but RUC, maintenance, insurance and depreciation are all real costs. They are cheaper to run, not free.
Misconception 2: "EVs do not pay anything toward roads"
Reality: EVs now pay road user charges by distance, just as petrol cars pay excise at the pump. Both contribute to roads.
Misconception 3: "Public charging is as cheap as home charging"
Reality: Public fast charging costs much more per unit than home off-peak charging. Where you charge changes the running cost a lot.
Misconception 4: "Petrol cost per km is fixed"
Reality: It moves with fuel prices, which can swing widely. A petrol car's running cost is more volatile than an EV's energy cost.
Misconception 5: "The cheaper car to run is always the cheaper car to own"
Reality: A higher purchase price or steeper depreciation can outweigh running savings, especially for low-mileage drivers. Total cost of ownership is what counts.
Misconception 6: "Maintenance is the same"
Reality: EVs generally need less servicing (no oil changes, fewer moving parts), though tyres and the eventual battery are factors. The maintenance profiles differ.
Use your real annual distance, your home charging cost, current RUC and fuel prices, and the purchase prices you are weighing. Total cost of ownership over your ownership period, not the cost to fill up, is the figure that answers "EV or petrol for me?"
🎯 Test Your Knowledge
Quiz on EV vs Petrol Running Costs
Related guides
- Car Running Costs NZ, a related guide in the same area.
- Rates and Property Running Costs Guide, a related guide in the same area.