Leaf vs Aqua: what Canterbury drivers actually pay in RUCs

Running a used Nissan Leaf or Toyota Aqua in Christchurch looks cheap until you model the real annual costs. Here is what the numbers actually say.

The used-car market in Christchurch has two very popular answers to the question of cheap motoring: the Nissan Leaf and the Toyota Aqua. Both come in from Japan in volume, both sit in a similar price band once you account for compliance and dealer margin, and both promise low running costs. A tidy 2018 Leaf ZE1 with 40 kWh battery is sitting around $18,000 to $22,000 on the books right now. A 2018 to 2020 Aqua in similar condition runs $14,000 to $18,000. The Leaf costs more to buy, but the assumption is that you make it back on fuel. Whether that is actually true depends on how many kilometres you drive and what you pay for power versus petrol.

Let us put some real numbers on it.

The RUC reality on a Leaf

From April 2024, light EVs pay $76 per 1,000 km in road-user charges. That rate applies regardless of where you charge, how efficient your driving is, or whether you are commuting down Blenheim Road or blasting down the Southern Motorway. You buy RUC licences in blocks from NZTA, and you are legally required to have them paid up before you hit the road. There is no grace period and no fuel-excise offset.

A Christchurch commuter doing 15,000 km per year pays $1,140 in RUCs. Push that to 18,000 km and it is $1,368. That is $95 to $114 per month before you think about electricity, insurance, or tyres.

Now add charging costs. A 40 kWh Leaf at real-world efficiency of around 6 to 6.5 km per kWh will consume roughly 2,300 to 2,500 kWh over 15,000 km. At a typical home overnight rate of about $0.28 per kWh, that is $644 to $700. Total energy plus RUC cost for a year of Leaf driving: approximately $1,784 to $2,068.

If you are relying on public rapid charging because you live in an apartment or have no off-street parking, those numbers look worse. Rapid charge rates in Christchurch typically run $0.55 to $0.65 per kWh. The same 2,500 kWh costs $1,375 to $1,625, and suddenly the Leaf's energy bill alone is competitive with running a petrol car.

What the Aqua actually costs per year in fuel

The Toyota Aqua is a genuine 4 to 4.5 L/100km car in mixed driving, maybe nudging 5 L/100km on a cold Canterbury morning with the heater running flat out. Call it 4.5 L/100km across a realistic Christchurch year.

At 15,000 km, that is 675 litres of 91 octane. At $2.65 per litre, that is $1,789 for the year. At $2.90, it is $1,958. No RUCs on top, because petrol excise already covers road contribution.

So a home-charging Leaf owner doing 15,000 km pays roughly $1,784 to $2,068 all in. An Aqua owner doing the same distance pays $1,789 to $1,958 in fuel. Those numbers are almost identical, which will surprise a lot of people who bought a Leaf expecting to cut their energy bill in half.

The RUC change is the reason. Prior to April 2024, a Leaf owner at 15,000 km would have been paying only that $644 to $700 in home charging costs, making the EV genuinely and significantly cheaper to run. The playing field is a lot flatter now.

Where the Leaf still has an edge, and where it does not

Servicing costs favour the Leaf clearly. No oil changes, no timing chains, no transmission fluid, no spark plugs. A reasonable annual service budget for a Leaf is $200 to $300, mostly tyres and brake fluid. An Aqua needs a proper service every 10,000 km or 12 months and while it is not an expensive car to maintain, budget $400 to $600 a year at a reputable independent workshop, more if the hybrid battery starts showing its age.

At 150,000 km, the Aqua's hybrid battery is a known point of concern. Replacements from a Japanese import supplier run $1,500 to $2,500 fitted. The Leaf's 40 kWh battery is generally holding up better than the older 24 kWh cars, but degradation is real, and a Leaf showing 10 to 11 bars on the battery gauge at purchase is worth scrutinising before you sign anything.

Insurance comes out similar for both. Comprehensive on a $20,000 car for a 40-year-old Christchurch driver is roughly $900 to $1,300 depending on your insurer and history. Neither car is particularly expensive to insure relative to its price.

Tyres are where the Leaf quietly bites. The extra weight of the battery pack is harder on rubber, and Leaf tyres tend to wear faster than comparable Aqua tyres, especially if you use the regenerative braking aggressively. Budget a tyre replacement cycle of 25,000 to 30,000 km on a Leaf versus 35,000 km on an Aqua.

For a Canterbury buyer doing 15,000 km a year, with a driveway charger and no unusual driving patterns, the total annual running cost difference between these two cars is now measured in hundreds of dollars, not thousands. The Leaf wins on servicing. The Aqua wins on tyres and buying price. The RUC change has genuinely shifted the calculus, and anyone still quoting pre-2024 running-cost comparisons is working from outdated sums.