Electric cars tested by Which?Nissan Leaf and Peugeot iOn in the Which? test lab

07 September 2011

Nissan Leaf

We've tested the Nissan Leaf electric car in the Which? lab

Which? has put the Nissan Leaf and Peugeot iOn electric cars through our unique, in-depth lab tests.

The two cars are the first battery-powered models to be subjected to our realistic efficiency tests, which show that neither vehicle is entirely emission-free.

Read our Nissan Leaf and Peugeot iOn reviews to find out more, including test results for performance, practicality and safety.

Electric car range tested

We tested the range of the two cars using a mixture of urban, out-of-town and motorway driving, with partial (but not constant) use of ancillaries like the air conditioning.

The Leaf can go 73 miles between charges, while the iOn's range is 58 miles.

73 milesrange of the Nissan Leaf between charges, according to Which? testing

Both figures fall short of the manufacturers' claims, of up to 100 and up to 93 miles respectively, but are a fair indication of the cars' range under realistic conditions. 

If no ancillaries are used, or if the conditions are different (ie: if the cars are driven smoothly, at a consistent low speed, or over flat terrain), then this range would increase slightly. Equally, the range would be likely to decrease under adverse conditions, when the driver needs to use the heater, lights and wipers. 

Electric car efficiency

Like all electric cars, both the Leaf and iOn have been dubbed 'emission free'. In some respects this is true because nothing comes out of the tailpipe during driving, which is clearly preferable to the exhaust gases emitted by conventionally-engined cars.

Peugeot iOn

The Peugeot iOn has the lowest CO2 emissions of any car we've tested

However CO2 is emitted through the production of the electricity used to charge them.

Our tests showed that the Leaf uses an average of 20.39 kilowatt hours (kWh) to cover 100km. The iOn uses an average of 16.94kWh to go 100km.

Using the latest figures from the Department for Energy and Climate Change, which state that an average of 521 grams of CO2 are emitted per kWh of electricity generated in the UK, the Leaf's CO2 emissions equate to 106g/km and the iOn's to 88g/km, according to our tests.

The iOn's CO2 emissions are the lowest we've tested to date, but the Leaf's 106g/km figure has previously been bettered in our tests by the VW Polo BlueMotion, an economy-focused diesel car. 

That said, it's still difficult to make strict like-for-like comparison between electric and conventionally-fuelled cars, due to the nature of the different fuel supply chains.

88g/kmCO2 emissions of the Peugeot iOn, the lowest of any car we've tested

Zero emissions

The precise CO2 output of electric cars will vary depending on exactly how they are charged. For example, if charging is supplemented by solar power, then the CO2 figure will be lower - and so could theoretically drop to zero if an entirely renewable source was used.

But many drivers will be pleased to hear that officially, CO2 emissions are listed as zero - so neither car is subject to vehicle excise duty (car tax).

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