Electric automotive ranges can plummet by as much as 40% in winter, check reveals

It’s a pretty well-known fact that efficiency of batteries in electric cars can decline when temperatures plummet – but just how much will winter weather wipe off the claimed range of some of the most popular EVs?

Real-world tests reveal the best-case scenario will see range slashed by 16.5 per cent – and the worst results in two fifths of the quoted distance disappearing.

In fact, the ten electric cars worst affected shed between 80 and 132 miles of their official ranges.

This is according to What Car?’s biannual Real Range tests – one carried out in summer and another in winter – in which the latest EVs are driven until their batteries run completely flat to understand how close to their claimed figures they really get.

The aim is to understand the difference between the ‘official’ quoted ranges of EV models based on laboratory measurements and what drivers can really expect to achieve when driving normally on the road.

The automotive title has been testing EVs in this way for over three years. Of the near-60 cars that have undergone assessment, 30 models in showrooms currently have been tested in winter conditions.

We countdown the 10 that miss their claimed ranges by the biggest margins. And we explain how the tests are carried out as well as the reasons behind EVs being less efficient in winter months.

EVS THAT MISS THEIR OFFICIAL RANGES MOST IN WINTER

10. MG4 Long Range SE/Trophy: -30.2%

This version of the MG4 EV is one of a few models What Car? has tested both in winter and summer conditions.

In the warmer season, the range was 253 miles. That’s just 28 miles shy of the claimed 281-mile figure. However, when driven to a flat battery in the winter test, the range dropped by 83 miles to just 196 miles in total. That’s 30.2 per cent less than claimed.

9. Kia EV6 RWD GT-Line: -30.5% 

Like the MG4 EV, Kia’s svelte EV6 GT-Line has undertaken both What Car?’s summer and winter Real Range tests – and the difference is stark.

In the hotter of the two seasons, it ran out of battery after 278 miles. That’s a whopping 50 miles (15.2 per cent) short of its official 328-mile stat. But in winter, things get doubly worse, with the range dropping by 100 miles, which is down 30.5 per cent on the distance customers are led to believe their EV6s can take them on a full charge.

8. Audi Q4 e-tron 50 quattro S line: -30.7%

What Car? tested the Audi Q4 e-tron in 2022 and since then there has been updates to the line-up, though the model remains largely unchanged.

The impact of winter conditions results in a maximum range of 201 miles starting with a fully recharged battery. This is 89 miles (-30.7 per cent) short of what the official range figure tells customers they’ll get from this pricey Audi.

7. Renault Megane E-Tech Equilibre – 32.0%

Two versions of Renault’s Megane E-Tech have been tested by What Car? and this one (fitted with smaller wheels) performed worst of the pair.

While Renault’s official claimed range is 275 miles for this particular derivative with 18-inch alloys, the Real Range winter test found it could only cover 187 miles until the battery went flat. It means a third of the car’s range disappears.

6. Jeep Avenger Summit: -33.2%

One of the four models in the top 10 to have been tested in 2024, the Jeep Avenger is another EV to miss its official range by a third in winter conditions.

Owners might believe they can cover 244 miles between charges but the reality at this time of year is that the car’s battery is only good enough for 163 miles. That’s an 81-mile shortfall – the equivalent of driving from Liverpool to Sheffield. 

5. Volkswagen ID 7 Pro Match (no heat pump): -33.7%

Volkswagen’s ID.7 is an executive saloon model that is designed to appeal to high-mileage reps looking for a flash – but green – vehicle with cheap company car tax benefits.

But for those looking to trot up and down the country might be alarmed to hear that the Pro Match version – without a heat pump – delivers 129 miles less than is claimed. While official stats quote 383 miles on a full charge, winter conditions limit this to just 254.

4. Ford Mustang Mach-E Extended Range RWD: -34.8%

In terms of the biggest mileage difference in official and winter tested range, the Ford Mustang Mach-E Extended Range RWD performs worst of all.

It loses a staggering 132 miles of range when comparing the two tested results; the equivalent of driving from Birmingham to Leeds.

3. Lexus RZ 450e Takumi: -36.7%

In the latest winter test results, Lexus’ RZ fell well short of the official range claims customers will see on the Japanese brand’s website and in brochures inside showrooms.

While drivers are told they can get up to 251 miles from this premium SUV, the reality in winter is that it will achieve just 159 miles. For a large family model like this a range of less than 160 miles might be too little for many buyers.

2. Lexus UX 300e Takumi: – 37.7%

Another electric Lexus tested in the last 12 months is the UX 300e, which What Car? put through the winter test procedure in 2024. And it performed even worse than its bigger RZ sibling.

A winter Real Range measurement of 170 miles is 103 short of the 273-mile claim.

1. Fiat 500 42kWh Icon: -40.4%

Of all the currently-on-sale electric cars subjected to What Car?’s winter Real Range test, the Fiat 500 has one of the shortest claimed ranges (only the Ora Funky Cat/03 has a shorter official range). However, it is this dinky city model that misses its quoted figures by the greatest percentage.

While 198 miles is what the official test puts to customers, in winter conditions they should only expect to see 118 miles from a full charge, essentially chopping two fifths off its claims. 

See the Real Range results for every electric car tested by What Car?

How does What Car? test electric car Real Range?

Because it would be far too dangerous to deliberately run EVs out of charge on the public road, What Car? instead conducts its Real Range tests at the Horiba-MIRA proving ground in Warkwickshire. 

Winter tests are usually conducted in late January to early February when temperatures are unlikely to rise above 10 degrees. 

Each car follows a simple test route of roughly 19 miles, which includes 2.7 miles of simulated stop-start urban driving, 5.5 miles at a steady 50mph and 11 miles at a constant 70mph. 

The rationale for the high percentage of high-speed cruising is that drivers who want to travel long distances in one hit are likely to be using the motorway network.

Every car is charged to 100 per cent and then left out in the open overnight, for roughly 14 hours in temperatures between 0 and 2 centigrade. The following morning, all of the EVs are plugged in again to make sure they are fully charged, before tyre pressure are checked, the climate control set to an equal temperature and headlights switched on.

Eco (or the closest equivalent) driving mode is used, and the cars are left in their default regenerative braking setting – if an ‘automatic’ or ‘adaptive’ mode is available, this is selected.

Each model is then driven repeatedly around the test route in convoy, with driver changes and a switch in running order at the end of each loop. This is carried out until the battery runs completely flat.

Why do EV ranges fall more in winter?

It’s firstly important to point out that manufacturers make clear that the official ranges quoted on their websites and marketing material are based on a consistent test every model sold in Europe is mandated to undertake to provide efficiency and economy data.

As with miles per gallon (mpg) figures quoted for petrol, diesel and hybrid cars, the official range measurement is for ‘comparison purposes only’ and not necessarily a true reflection of what can be achieved on the road.

However, given the importance that electric car owners should never run out of battery, experts argue that figures presented to buyers should be as realistic as possible.

Steve Huntingford, editor of What Car, told us: ‘Our Real Range testing shows an average drop in the range of 18 per cent of pure electric models in winter versus summer conditions.’

Steve says this is due to colder weather having a ‘detrimental effect on the efficiency of lithium-ion batteries’. 

He explained: ‘Models fitted with a heat pump, which helps to maintain the battery’s temperature, are affected less, but drivers of most EVs will need to plan to charge up more often in the winter months.’

Electric cars also do not generate much waste heat like vehicles with internal combustion engines, which use this to their advantage.

In a petrol or diesel car, waste heat produced by the engine is used to warm the vehicle cabin when the heater is turned on.

Drivetrains in EVs are generally between 75 and 90 per cent more efficient by comparison and the moving parts in the electric motors don’t generate surplus heat.

That means drivers of electric cars will have to rely on the vehicle’s heating system to get warm when they drive, thus sapping power from the battery and reducing range.