EV running costs in 2026: do the sums finally add up?

The Clean Car Discount is gone, RUCs are locked in, and petrol sits around $2.80 a litre. We run the real numbers on the Leaf, MG ZS EV, and BYD Atto 3 against a comparable petrol import.

The pitch for EVs used to lean heavily on two props: government subsidies and no road user charges. Both are gone. What's left is the underlying cost of electricity versus petrol, the purchase price gap between used EVs and comparable petrol imports, and whatever you believe about long-term reliability. Run those numbers honestly and the answer is less obvious than either camp wants to admit.

The three EVs that dominate the Canterbury used market right now are the Nissan Leaf, the MG ZS EV, and the BYD Atto 3. They sit at different price points, different ages, and have meaningfully different real-world ranges. A useful petrol benchmark is the Toyota Corolla hatchback or the Mazda CX-5, depending on whether you're comparing a city runabout or a family SUV.

What you pay to buy

A 2018 to 2020 Nissan Leaf, 40kWh, sits between $18,000 and $24,000 in Canterbury right now, depending on condition and battery health. Mileage matters less than battery state of health on these — a 60,000km example with a degraded battery is a worse buy than an 80,000km car that's been treated well. The 62kWh e-Plus variant commands a $4,000 to $6,000 premium and is worth it if range anxiety is your main concern.

The MG ZS EV in its first-gen form (pre-2022) comes in around $25,000 to $30,000. The 2022 and later facelift, with the larger 72.6kWh battery, is closer to $33,000 to $38,000. Parts availability is improving but MG's NZ dealer network is thin outside the main centres, and that matters when something goes wrong.

The BYD Atto 3 is the newest of the three and prices reflect that — expect $38,000 to $46,000 for a low-mileage example. You're buying a modern car with a real warranty, but you're also paying near-new money for an unknown long-term reliability record in this market.

A 2019 to 2021 Mazda CX-5 petrol in comparable condition sits at $26,000 to $34,000. A 2020 to 2022 Toyota Corolla hatch is $22,000 to $27,000. The purchase price gap has narrowed considerably since 2022, and that changes the payback arithmetic substantially.

The annual running cost breakdown

RUCs first. At $76 per 1,000km, a Canterbury driver doing 15,000km a year pays $1,140 in RUCs on any of the three EVs. That's fixed regardless of which car you choose. Add WoF (annual after three years, around $60 to $80 at a reputable workshop), registration around $108 a year, and you're at roughly $1,350 in fixed annual costs before energy or servicing.

Energy cost for EVs: the MG ZS EV uses approximately 17kWh per 100km in mixed driving, the Leaf about 16kWh, the BYD closer to 18kWh. At 32 cents per kWh residential, that's $0.054 to $0.058 per kilometre, or $810 to $870 per year at 15,000km. Charge mostly at home and these numbers hold. Lean on public fast charging at $0.55 to $0.65 per kWh and you can double that figure easily.

The comparable CX-5 petrol, averaging 8.5L per 100km in mixed Canterbury use, costs around $3,570 a year in fuel at $2.80 per litre. The Corolla, at 7L per 100km, is around $2,940. WoF, rego, and a service interval are broadly similar once you normalise for vehicle age.

So the EV saves roughly $2,000 to $2,700 a year in energy costs compared with a petrol CX-5, and around $1,500 to $2,000 against the Corolla. Against those savings, you're paying $1,140 in RUCs that a petrol car doesn't see separately (it's folded into fuel excise). The net energy advantage for the EV lands around $800 to $1,600 per year depending on the comparison. That's real money, but it's not transformative.

What breaks, and what it costs

The Leaf's Achilles heel is well documented: the 40kWh pack in 2018 and 2019 cars has no active thermal management, which means New Zealand's mix of cold winters and warm summers ages the cells faster than the spec sheet suggests. A battery health check via Leaf Spy before purchase is non-negotiable. A replacement battery, if you need one, is $8,000 to $14,000 fitted. Parts for the rest of the car are fine — it's a Nissan, and the Japanese supply chain is solid.

The MG ZS EV's known issues at higher mileage centre on the charging port and onboard charger unit. The infotainment system is ordinary and the 12V auxiliary battery fails more often than it should. Repair costs are manageable but sourcing parts can mean waiting three to four weeks if local stock is out.

The BYD Atto 3 hasn't been in NZ long enough to have a proper mileage-related fault pattern yet. Blade battery technology looks promising and BYD's internal components are vertically integrated in a way that could go either way for independent repairers — either proprietary lock-in or excellent parts availability direct from the importer. The jury is genuinely out.

For a straight three-year ownership calculation, the Leaf at $21,000 all-in is still the entry point that makes the running cost savings most meaningful. The BYD at $42,000 requires you to drive a lot of kilometres, keep the car a long time, or value the modern safety tech enough to pay for it separately. The MG sits in the middle and is probably the most honest value proposition of the three if you can find a post-2022 facelift at a fair price.

The sums don't lie, but they don't tell a simple story either. EVs cost less to run year to year, but the purchase price gap and the RUC liability mean the payback period on a Canterbury typical-use pattern is three to five years, not eighteen months. Know that going in and the decision gets a lot clearer.