It says a lot about the general perception of electric cars when the phrase “range anxiety” has become a household term. The shorter driving range that an EV offers compared with petrol or diesel, and the fears of unreliabile and inconveniently slow charging times at en route charging stations, still make battery electric cars a difficult option for high-mileage drivers.
But, a record set by military charity Mission Motorsport for the longest distance driven in a Renault Zoe, at 475.4 miles (or 9.14 miles per kilowatt hour or mkWh), puts a spotlight on what can be done to get more range from an EV. We’re not talking duct-taped panel gaps and folded-in mirrors to reduce drag, either; the Mission Motorsport hyper-mile challenge was undertaken in two entirely standard Renault Zoe Z.E. 52 cars, which have an official WLTP range of 245 miles.
The only difference is that the record-breaking car had its tyres provided by ENSO; a tyre company setting out to offer environmentally-friendly road tyres that aim to last longer, emit fewer particulates and improve EV range. The other Zoe ran on standard-fit Michelin tyres, yet still managed an impressive 424.7 miles.
But, while doing between 19 and 23mph for more than 24 hours around Thruxton circuit is one thing, getting better range in everyday driving is another.
How is EV efficiency affected as you drive?
A huge variety of factors that affect an electric car’s efficiency and range. Very cold weather can reduce the maximum range by some 20-40 per cent, while speed also has a big impact. An electric car doesn’t have gears like a petrol or diesel car so, in simple terms, an electric motor driving an EV is working twice as hard at 70mph as it is at 35mph, which is why steady motorway speeds will see the range on an electric car drop more quickly. Free-flowing suburban or town roads is where EVs are at their most efficient.
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 regarding your electric car
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 per cent through normal driving and up to 30 per cent on descents.”
Is air-con or an open window best for staying 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 per cent 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.
What about car heating?
It’s an expensive option but this more efficient heating technology is estimated to use about 40 per cent less energy than the traditional heating systems used in many EVs. A worthwhile addition if you routinely want to use the car’s full range potential throughout the year, but make sure that you’ll benefit enough from the more efficient cold-weather running to justify the additional cost.
Other efficiency measures for your EV
Other simple things that can help with range include checking your tyre pressures (low pressures will reduce efficiency) and making sure that you’re not carrying unnecessary weight in the car.
Of course, if you want to draft a lorry for your entire motorway journey, you’ll see great efficiency and range from your electric car. More realistically, keeping your driving smooth, pre-setting the cabin temperature and maximising your gains from the brake regeneration system will add up to deliver big gains in EV efficiency and range.
This article is kept updated with the latest information.
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