Leaf vs Aqua: what it actually costs to run each car in Canterbury

The Clean Car Discount is gone and light EV RUCs are here to stay. We crunch the real weekly numbers on a used Nissan Leaf versus a Toyota Aqua for Canterbury drivers.

Used car prices have settled enough in the past year that the gap between a tidy 2018 Nissan Leaf and a comparable 2018 Toyota Aqua is real money, not rounding error. A clean Leaf ZE1 with a healthy battery (SOH above 85 percent, worth checking on the Leaf Spy readout before you buy) sits around $16,000–$19,000 at Canterbury yards right now. A same-year Aqua in similar nick runs $13,000–$15,500. Call it a $4,000–$5,000 premium to go electric, without any government help to close that gap.

That premium needs to pay itself back through lower running costs. Whether it does depends almost entirely on how far you drive.

Crunching the weekly fuel and energy cost

The Aqua is genuinely frugal. Real-world Canterbury driving, including the hills and stop-start school-run stuff, puts it at around 4.5–5.0 litres per 100 km. At $2.70 per litre, that's roughly $12.15–$13.50 per 100 km. If you're doing 300 km a week, you're spending $36–$40 on petrol.

The Leaf, charged at home overnight, costs around $0.30 per kWh on a typical residential rate. The ZE1's real-world consumption runs about 17–18 kWh per 100 km in mild weather, nudging toward 21–22 kWh in a Canterbury winter when the heater is working hard and the battery is cold. Call it 19 kWh per 100 km as a year-round average. That's $5.70 in electricity per 100 km.

But then there's the RUC. At $76 per 1,000 km, that adds $7.60 per 100 km. So the Leaf's all-in cost per 100 km is around $13.30. Almost identical to the Aqua.

At 300 km a week, the Leaf costs roughly $39.90 in combined energy and RUC. The Aqua costs $38–$40. The gap is nearly nothing.

Push the weekly distance to 500 km and the Leaf still doesn't pull away dramatically. You're saving maybe $8–$12 a week over the Aqua. That's $416–$624 a year. To recover the $4,500 purchase price premium, you're looking at seven to ten years of high-mileage driving. That's a long time to hold a car whose battery pack is already six years old.

Where the Leaf wins and loses on the other costs

Servicing is the Leaf's genuine advantage. No oil changes, no timing chain, no transmission fluid. A basic annual service with a fluid check and brake inspection runs $150–$200 at an EV-friendly workshop. The Aqua's hybrid system is famously reliable, but it still needs coolant, brake fluid, and the occasional spark plug. Budget $250–$350 a year in servicing for the Aqua.

Both cars are on annual WoF checks after the three-year mark, so that's even. Tyres are roughly comparable, though the Leaf is heavier and does scrub fronts slightly faster if you use the regenerative braking hard coming down from Dyers Pass.

The one cost Canterbury Leaf owners often don't see coming is the 12V auxiliary battery. It's a standard lead-acid unit and it does not like being left in a cold garage for three weeks while you're on holiday. Replacements run $180–$280 fitted. Budget for it.

The Aqua's weak point is the HV battery, but the 2018 generation is well past the period where failures were common. A replacement is eye-watering (over $3,000 if you need a new one), but it's an unlikely expense in a car with documented service history and no warning lights.

What the numbers actually tell you

If you're doing under 350 km a week, the Leaf doesn't save you enough in running costs to justify the higher purchase price on a purely financial basis. The maths only starts to favour the Leaf clearly when weekly distances climb above 500 km, and even then, you need the battery pack to stay healthy for the years it takes to break even.

For a Canterbury driver doing a standard commute plus weekend runs, the Aqua is the harder value to argue against. It's cheaper to buy, costs nearly the same to run, and carries none of the battery anxiety that comes with a six-year-old Leaf on a cold July morning.

That's not an anti-EV argument. A newer Leaf, or a BYD Atto 3, or a used Model 3, changes the picture. But a 2018 Leaf at a $4,500 premium over a 2018 Aqua, in a world where RUCs now level the energy cost playing field, needs you to drive a lot of kilometres and ask very few questions about what happens when the pack degrades further.