In-depth reviews

Hyundai Ioniq review - MPG, CO2 and Running Costs

Fantastic on-paper efficiency claims are hard to match in the real world

Hybrids like the Ioniq are all about efficiency, so real-world economy is just as important as the Hyundai’s claimed 79g/km CO2 emissions and 83mpg - or 252mpg/26g/km on the plug-in. When we had it on test, the hybrid Hyundai returned 47.9mpg, which was 9.1mpg less than a Toyota Prius we also tested. This difference is surprisingly large and means you’ll spend an extra £223 per year at the pumps by running the Ioniq.

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Higher emissions also means the Hyundai attracts a greater 15 per cent Benefit-in-Kind rate than the 11 per cent Prius, so although a high-spec Ioniq is around £900 cheaper to buy, it will actually cost higher-rate company car drivers upwards of £300 per year more to run.

Go for the optional 17-inch wheels, and CO2 emissions rise significantly to 92g/km – almost as high as some regular diesel-powered eco cars.

To help maximise efficiency Hyundai fitted an aluminium bonnet and boot, as well as lightweight suspension components, which saved around 25kg over conventional items.

When it comes to efficiency, every gram counts, so stripping mass out of a car boosts fuel economy and lowers CO2 emissions. However, the welcome benefit is that lighter cars also handle and perform better; while the Ioniq won’t set your pulse racing, the chassis is relatively capable.

The plug-in model takes around 2.5 hours for a full top-up using a home wallbox. Hyundai claims a pure-EV range of around 39 miles, but you'll do well to get about two thirds of that total in real-world motoring. The official fuel economy figure of around 252mpg is pretty unrealistic, too, although with regular plug-ins, this could still be a very efficient commuter car.

Insurance Groups

Just as with its list prices, so with insurance groups, the Ioniq looks a little better than the Toyota Prius. Insurance groups for the Prius start at 15, but the two hybrid Ioniqs are between 10 and 12, depending on the trim, while even the electric model is in 16 or 17.


After three years and around 36,000 miles, the Ioniq is expected to retain around 47.8 per cent of its original value. That means if you go for a £23,500 1.6 GDi Hybrid Premium SE – our pick of the range – you’ll get around £11,000 for the car when you come to sell it in three years time. 


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