What affects an electric car’s range

The range on the spec sheet is a figure obtained under standard conditions. In real life, the same car can go much further or much less far depending on a few factors. Some are down to you, others to the weather or the battery’s condition.

Speed

This is the most important factor on a long trip. Air resistance rises with the square of speed, so at 130 km/h the car uses far more than at 90 km/h. Unlike a petrol car, an EV is most efficient in town, where it moves slowly and recovers energy under braking.

Temperature

Cold reduces range for two reasons: a cold battery works less efficiently, and heating the cabin draws energy from the same battery. In winter tests by the Norwegian motoring club NAF, the average loss against official range was about 20%, with big differences between models. Extreme heat matters too, through air conditioning and battery cooling, but less so.

Heating and air conditioning

A car with a heat pump uses much less energy for heating than one with resistive heaters. Heated seats and steering wheel are far more efficient than heating the whole cabin.

Tyres and load

• Under-inflated tyres increase consumption.
• Big wheels and wide tyres look good but use more energy.
• Winter tyres have higher rolling resistance.
• Roof boxes and bike racks spoil the aerodynamics.
• Extra weight matters most in town, with repeated starts.

Terrain

Going uphill uses more energy, but on the way down you recover some of it through regenerative braking. A mountain round trip still uses more than a flat one.

Battery health

An aged battery has less capacity, so less range at any speed. Sometimes a sudden drop is not down to wear but to one weaker cell group limiting the whole battery. A battery test shows exactly what the cause is.