22 September 2023
We crunch the numbers on the electric cars on sale today to see which come closest to hitting their advertised figures
Plenty of electric cars have impressive claimed range figures but managing to achieve them is another story. With the increasing number of EVs to choose from, buyers are hunting for the most energy-efficient electric cars to really make the most of their batteries between charges.
Electric car efficiency is measured by calculating its miles per kilowatt hour used, shortened to mpkWh. For example, a Volkswagen ID 3 with a 77kWh battery would require an efficiency of 4.5mpkWh to achieve its officially rated 347 miles of range.
A vehicle’s efficiency is affected in several different ways, with aspects such as weight proving to be a key factor in positively or negatively impacting range.
The Audi Q8 E-tron, for example, is powered by a 106kWh battery, but weighs a staggering 2585kg, meaning it can deliver only around 2.9mpkWh.
Larger, SUV-style electric cars are also usually impacted more by drag, which reduces their range compared with sleeker, more aerodynamic sports cars and hatchbacks.
The range and efficiency of electric cars are also heavily influenced by the weather conditions and outside temperatures. Warmer temperatures mean a battery’s chemical reactions can occur faster and offer higher range, whereas colder weather requires more energy, reducing range.
Other aspects dictated by the driver, such as how fast you drive and the use of climate control or air conditioning, also affect range. A car will often be able to travel further on a single charge in the city compared with on the motorway, as more power is required to sustain higher speeds and handle the increase in drag.
Now you know how an electric car’s efficiency is impacted – but just how efficient are electric cars in the real world, and which are the most efficient electric cars on sale today? Our list below details the best EVs to squeeze the most mileage out of your battery.
Most efficient electric cars on sale
Peugeot e-308
Claimed efficiency 4.9mpkWh
Autocar’s test efficiency tbc
The Peugeot e-308 is due in October 2023 and Peugeot has made some impressive claims about its potential range and efficiency figures, labelling it “a benchmark among 100% electric vehicles in the C-segment”.
Peugeot says that with the e-308’s EV-specific redesign, low-friction tyres and aerodynamic wheel options applied, the new e-308 will be capable of producing 4.8mpkWh in hatchback guise.
Of course, real-world tests will prove whether it can achieve that ambitious figure, and if it can, it will be the most efficient electric car on sale.
The new e-308 is powered by a 51kWh (usable) battery with 252 miles of range. The French car maker has priced the hatch from £40,050 here in the UK, and the estate will follow later in 2023.
Read all about the new Peugeot e-308
Tesla Model 3
Claimed efficiency 4.7mpkWh
Autocar’s test efficiency 4.5mpkWh
The Tesla Model 3 is one of the electric car pioneers. The current version is available with 305 miles of range in its entry-level form, rising to 374 miles for Long Range models, or 340 miles in the blisteringly fast Performance variant.
In standard-range guise, the Tesla Model 3 returned a brilliant 4.5mpkWh. That converts to 258 miles of range, which instantly makes the Model 3 one of the most efficient electric cars you can buy.
Expect it to further cement its position at the top in 2024, as the Model 3 will gain a facelift with updated battery tech (Tesla doesn’t detail battery sizes), which ups the standard-range model’s trekking distance to 344 miles. We tested it earlier this year and returned a figure of 4.7mpkWh. Impressive.
Volkswagen ID 3
Claimed efficiency 4.5mpkWh
Autocar’s test efficiency 3.8mpkWh
Having entered its second generation in 2023, the Volkswagen ID 3 has proved itself to be one of the most efficient electric cars on sale.
Volkswagen’s first-ever bespoke electric hatchback, which launched back in 2019, is now available with both a 58kWh battery and a 77kWh unit. With that larger battery, Volkswagen says the ID 3 is able to travel 347 miles on a single charge.
In our tests, the ID 3 matched the Kia Niro EV, recording 3.8mpkWh. That calculates to 292 miles of range in the real world, which places the ID 3 near the top of the list of the most efficient electric car on sale.
Read our Volkswagen ID 3 review
Kia Niro EV
Claimed efficiency 3.9mpkWh
Autocar’s test efficiency 3.8mpkWh
The popular Kia e-Niro was renamed this year with the launch of its boldly styled second-generation model. Now called the Kia Niro EV, it still packs the same versatile powertrain set-up as the previous car.
It combines a 67kWh battery (64.8kWh usable capacity) with a 201bhp electric motor and has a claimed 285 miles of range. There is one downside: the Niro EV still falls behind its competitors in terms of charging speeds, with a maximum of 72kW.
But that might not matter, given the Niro EV’s impressive energy efficiency, which makes it one of the most efficient electric cars available in the UK. It’s claimed to be 3.9mpkWh and our tests returned 3.8mpkWh – almost exactly as advertised. That equals 246 miles of range.
Vauxhall Corsa-e
Claimed efficiency 4.4mpkWh
Autocar’s test efficiency 3.7mpkWh
The Vauxhall Corsa-e launched in 2021 with a 50kWh battery and 222 miles of range. Vauxhall doesn’t explicitly quote its mpkWh figures, but using that official 222 miles range figure and the size of the battery produces a figure of 4.4mpkWh.
Our test gave 3.7mpkWh, which calculates to around 185 miles of range. Similarly to the electric Fiat 500, the Corsa-e weighs around 1455kg, which helps the hatchback achieve its impressive efficiency score.
Keep an eye out, though, as Vauxhall is set to launch a revised version of the Corsa-e with battery updates that boost its range to 246 miles. In theory, that takes the Corsa-e’s efficiency up to around 4.8mpkWh.
Read our Vauxhall Corsa-e review here
MG 4 EV
Claimed efficiency 3.7mpkWh
Autocar’s test efficiency 3.6mpkWh
The MG 4 EV has taken the electric car world by storm, so much so that we named it the Best Electric Car of 2023 at the Autocar Awards.
Available in standard-, long- and extended-range specifications, the MG 4 EV is claimed to offer 323 miles of range with its largest, 77kWh (74.4kWh usable) battery and overall efficiency of 3.7mpkWh.
According to our tests, the MG 4 EV was one of two cars on this list to almost match its officially advertised efficiency. Our extended test resulted in a figure of 3.6mpkWh, compared to MG’s claimed 3.7mpkWh, which works out to 262 miles of range.
Hyundai Ioniq 6
Claimed efficiency 3.9mpkWh
Autocar’s test efficiency 3.4mpkWh
On the surface, the Hyundai Ioniq 6 appears to be one of the more ‘slippery’, aerodynamic electric cars on sale. That should, in theory, make it one of the most efficient.
The Ioniq 6 packs a punch, too. Single-motor, front-wheel-drive models produce 225bhp, while dual-motor, all-wheel-drive variants pump out a muscular 321bhp. Hyundai claims an efficiency rating of 3.9mpkWh, with the Ioniq 6 having a 77kWh (74kWh usable) battery, and advertises a range of 338 miles on a single charge.
Our test recorded slightly below that, at 3.4mpkWh, which equates to around 261 miles of range. Thankfully, the Ioniq 6 has an impressive maximum charging speed of 233kW.
Read our Hyundai Ioniq 6 review
Skoda Enyaq iV 80
Claimed efficiency 3.7-4.0mpkWh
Autocar’s test efficiency 3.4mpkWh
Skoda offers the Enyaq iV with a choice of two battery sizes in the UK: the 58kWh 60 model and the 77kWh 80, which offers 333 miles of range.
We tested the 77kWh model, which, SKoda claims offers, an efficiency score of between 3.7 and 4.0mpkWh.
Our road test threw up an average of 3.4mpkWh, which, translates to a real-world range of just over 260 miles. While a distance away from its claimed figures, that’s still fairly impressive for an SUV – and even pits it ahead of many of its smaller competitors.
Read our Skoda Enyaq iV review
Fiat 500 Electric
Claimed efficiency 4.8mpkWh
Autocar’s test efficiency 3.3mpkWh
The electric Fiat 500 is sold with one battery: a small 42kWh unit (37.3kWh usable) offering a claimed 199 miles of range. It’s powered by a single, front-mounted electric motor producing 117bhp and 162lb ft of torque.
The electric 500’s efficiency is aided by its compact size, because it weighs just 1365kg – lighter than the vast majority of the electric vehicle competition. Fiat claims you can hit up to 4.8mpkWh, which puts the 500 among the most efficient electric cars you can buy. While you might be able to climb up to this figure with some diligent city-only driving, our real-world test produced 142 miles of range – equivalent to 3.3mpkWh.
Renault Mégane E-Tech Electric
Claimed efficiency 3.9mpkWh
Autocar’s test efficiency 3.3mpkWh
The Renault Mégane E-Tech Electric might carry a familiar model name, but the E-Tech Electric is anything but.
This stylish hatchback is offered with a 60kWh battery which Renault claims offers 280 miles of range, and 3.9mpkWh. If it hits that figure, it’s ranked as one of the most efficiant electric cars on the market.
During our road test, the Megane achieved 3.3mpkWh, which works out to around 200 miles of real-world range. That’s not fantastic, and as you’ll see from the other contenders of our list below, beaten out by several of its rivals.