October 26, 2021

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How to get the best range from an electric car

We spoke to Linda Noble, one of the Mission Motorsport hypermilers. She was medically discharged from the army in 2018 after an 18-year military career, and proved to be one of the most efficient drivers on the Mission Motorsport hypermile record team, despite having never driven an electric car before. 

Advice from a record-breaker

“Drive as smoothly as you can,” was her chief piece of advice. “It’s the most important thing. The smoother you drive, the more efficient you get. Keeping a fairly constant speed is best. We weren’t speeding up and slowing down, just a bit of brake regeneration [see below] on the descents was all we used.”

Smooth driving is the first rule to getting the best range from an EV. 

Other efficiency gains

Looking well ahead so that you have plenty of time to slow down for traffic, and not using the brakes harshly or accelerating too hard, will get you big efficiency gains with little cost to comfort and convenience. 

This also makes good use of the brake regeneration systems (sometimes called Kinetic Energy Recovery Systems, or KERS) that feature in every electric car. When you lift off the accelerator, an EV automatically starts to use the electric motor as a generator to harvest the energy from the car’s natural forward momentum. 

The strength of that brake regeneration can vary. Many EVs offer a range of brake regen’ strengths, so it can feel no different to normal engine braking, or it can be so strong that you barely need to touch the brake pedal at all if the car has so-called “one pedal driving”. 

For some idea of how much energy the regen’ system can capture, an Energy Saving Trust report states that “energy recapture through regenerative braking is around 10% through normal driving and up to 30% on descents.”

Air-con or open window to stay cool?

AS you might imagine, the record-breaking Mission Motorsport team kept the air-con switched off to avoid its significant drain on the battery, but nobody wants to live with that level of discomfort in daily life, particularly not in an expensive new car. 

The Energy Saving Trust EV efficiency report cited above estimates that opening the window on a warm day will impact efficiency less than using air-con, provided you’re traveling at less than 45mph. 

At higher speeds, the air-con is a better bet for staying comfortable and maximising range, since the aerodynamic drag of an open window at these speeds substantially reduces efficiency. 

Almost all EVs offer the ability to pre-set the cabin temperature. This means that, if you’ve got the car parked and plugged in overnight, it’ll use mains electricity to get the cabin cooled or warmed ready for your departure time. Given that the climate control can use up some 20% and more of an EVs battery power in bad weather – therefore eating up nearly a quarter of your potential range – it’s well worth using the air-con pre-sets. 

The Eco driving modes in an EV often deliver reduced air-con functionality yet don’t turn it off altogether, which is a great energy-efficient way to maintain a comfortable temperature. 

And what about heating?

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