The most efficient EVs | The best ranked by miles per kWh
As more and more EVs hit the road, it’s important to consider how we measure their efficiency. Range is one thing, and battery capacity another, but neither of these elements are an equivalent measurement to miles per gallon (mpg) or kilometres per mile (kph).
When you want to work out how much electricity you’ll be spending, this is important.
Miles per kWh: Read our full guide
How do you work out miles per kWh efficiency?
To work out a like-for-like comparison with mpg, we need to consider the miles per kilowatt hour (miles per kWh) an EV can achieve. This is as close as we can get to an equivalent of mpg, because it tells you have many miles you can go using a certain amount of electricity.
To carry out the calculation, you need to take the EV’s range and divide it by its battery size. For example, a Corsa Electric has a 54kWh battery and a 222-mile range. Dividing the range by the battery size, we come to a figure of 4.44 miles per kWh.
It’s worth keeping in mind this isn’t the whole story though: the entire capacity of the battery isn’t usable at all times. In the real world, you’ll be able to use around 48.1kWh of the Corsa’s battery. This reduces the theoretical miles per kWh down to 4.6.
Do manufacturers disclose official miles per kWh figures?
You’ll be able to find official miles per kWh figures in the vehicle specifications (if they are disclosed). Range remains the headline figure. You’ll find that more and more EVs will now tell you your average mileage per kWh in some form or another.
Some will display it per mile, while others will use other set distances. For example, 30 kWh per 100 miles. This means for every 100 miles travelled, you’ll use 30kWh of your battery’s capacity.
What are the most efficient EVs currently available?
Generally, you can consider EVs that achieve more than 4.0 miles per kWh to be very efficient, and those offering more than 5.0 miles per kWh to be excellent.
We decided to carry out our own calculations using vehicles’ usable battery size and WLTP range figures. Here’s five of the best according to our calculations.
Tesla Model 3 (Long Range Rear-Wheel Drive)
WLTP range: 435
Battery size: 75kWh
Theoretical miles per kWh: 5.8
At the top of our list is the Tesla Model 3 Long Range Rear-Wheel Drive model. Recent tweaks mean those ordering this derivative can expect upwards of 5 miles per kWh. Interestingly, figures revealed by Tesla actually state that drivers can expect up to 4.97 miles per kWh, demonstrating that in real-world test conditions, things get more complicated than the simple calculations we’ve used in this article.
It will be interesting to see which manufacturers adopt miles per kWh as the go-to figure next. That aside, the 120-mile increase in range is a seriously impressive feat considering we believe the Model 3 hasn’t been drastically altered. It gets the same 75kWh battery pack that it’s had for the last few years.
Volkswagen ID.3 (58kWh)
WLTP range: 266 miles
Battery size: 55.4kWh (usable)
Theoretical miles per kWh: 4.8 miles per kWh
The Volkswagen ID.3 is available in a number of battery sizes, and the most sensible choice for many will be the 58kWh choice. In the real world, just over 55kWh of this capacity is usable, which results in an impressive, if theoretical figure of 4.8 miles per kWh.
Aside from efficiency, it’s also a great choice if you want a practical, all-electric car. Current prices show it needn’t be a pricy proposition if you’re thinking of leasing one either.
Compare Volkswagen ID.3 prices
Renault Megane E-Tech
WLTP range: 280
Battery size: 60kWh (usable)
Theoretical miles per kWh: 4.6
Renault’s all-new Megane E-Tech might have an old name, but it’s a brand-new car. And a seriously good one. Packed full of kit, it offers a glimpse at what we can expect to see from Renault’s electrified line-up in the future.
Considering it’s more of a crossover than a hatchback, our theoretical figure of 4.6 miles per kWh is all the more impressive; generally, the heavier and larger the car, the lower miles per kWh can be expected.
Compare Renault Megane E-Tech prices
Vauxhall Corsa Electric (54kWh)
WLTP range: 222 miles
Battery size: 48.1kWh (usable)
Theoretical miles per kWh: 4.6
The Vauxhall Corsa Electric is a go-to hatchback that’s perfect for those looking to make the jump from internal combustion to EV power. It’s the same as any Corsa inside, but it adds an impressive and affordable electrified powertrain.
Its 54kWh battery has a usable capacity of 48.1kWh in the real world. This results in an impressive 4.6-mile per kWh figure when its official combined WLTP range is taken into account.
Compare Vauxhall Corsa Electric prices
MG 4 (Extended Range)
WLTP range: 323 miles
Battery size: 74.4kWh (usable)
Theoretical miles per kWh: 4.3
The MG is a really fun EV to drive, and it’s equally pleasing when it comes to efficiency too. More specifically, the Extended Range variant achieves an admirable 4.3 miles per kWh based on its official range and usable battery stats.