Range is one of the key features that is mentioned with the launch of any EV. I know it’s something I’m guilty of too – it's the first thing I look for in the spec sheet. But with most new electric models now sporting over 300 miles of range, and fast chargers becoming more prevalent, range isn’t a problem for most people.
If you are planning to buy an electric car, you need a home charger – or at least a wall socket you can plug your car into. If you have this – unlike with an ICE car – you’ll be starting every journey at 100%. That means that if you’re driving less than, say, 200 miles before you get home, you’ll never have to use a public charger.
If you think about the day-to-day journeys you do in your car, that probably covers most of them. It’s only for those long-distance trips where you’ll need to plan in charging stops. I’m currently driving the Audi e-tron GT, which has a total range of around 260 miles, or nearer 200 on a cold day. Even then, range isn’t an issue, as I know that most motorway services have fast chargers – there’s a sea of Gridserve and Ionity chargers from Bath to London.
The Audi e-tron GT's dash gives efficiency in miles per kW
With the range issue practically solved then, it’s time to look at a different metric. With petrol and diesel cars we talk about efficiency and that’s something that is now more important with EVs. Charging your car has become more expensive, both at home and at fast chargers – though still not as expensive as petrol – so how far each kW of charge will get you, becomes the bigger question than range.
After all, a bigger battery might get you further on a single charge, but it will cost you more to charge it each time. Plus, if two EVs offer the same range but one has a smaller battery, it will be cheaper to run.
For ICE cars the common measurement, at least in the UK and US, is miles per gallon (MPG). However, for EVs, manufacturers are yet to all agree to a single metric. Some will use a European kWh per 100km (or 62 miles), while others use a more familiar miles per kWh. There’s even an eMPG mostly in the US, that works out an equivalent to ICE cars. This is handy for comparing EVs to ICE but probably less useful once you’re comparing EV to EV.
For the UK, I’m fairly confident that the miles per kWh (mi/kWh) will prevail as the metric of choice. It’s something that more manufacturers are quoting now, and it’s something that the dashboard of the Audi e-Tron GT shows me throughout the journey.
VW also uses mi/kWh in the UK and this ID.3 shows the advantage of a smaller car
With this measurement – as with MPG – the more miles you get per kWh, the less it will cost you to do per journey. And if you’re paying £0.69 per kWh or more at a fast charger, that’s good to know. What makes a good Mi/kW value will depend on the type of EV you have. A long range, aerodynamic SUV will have better numbers than a high-performance model.
The average for efficient EVs right now is between 3 and 4 miles per kWh. The Audi e-tron GT gets far less than this, usually around 2 miles per kW in the city and 3 miles per kW on the motorway. But just as you wouldn’t expect a V6 sports car to give you 40MPG, you can’t expect a sporty EV to deliver performance and efficiency. I recently drove a Maserati sports car that when I put my foot down, it drank fuel so fast that I watched the needle drop before my eyes.
Just as you’d struggle to find a high-performance ICE car that would give you more than 250 miles on a full tank, sporty EVs will always have shorter ranges. It takes lots more kW to shift an EV quickly.
As range figures on EVs start to plateau and drivers gain confidence in the availability of charging, mpkWh will become a bigger deal. My advice is before you buy an EV, look at the efficiency numbers, especially if you really want to save yourself money.
