What Car? Real Range: how we work it out

With demand for electric models soaring, What Car? has developed a new test that reveals the Real Range you can expect between charges. Here's how it works...

What Car? Real Range: how we work it out

Real Range testing

At the start of every Real Range test, the model in question driven at What Car?’s test centre until its battery is depleted to the point that the car will no longer drive.

What Car? Real Range: how we work it out

Real Range testing

Using a modified charging point with a built-in meter, we measure the energy (in kWh) required to fully recharge the battery.

What Car? Real Range: how we work it out

Real Range testing

Temperature impacts battery efficiency, so the car is ‘soaked’ overnight in an air-conditioned chamber at 18deg C while plugged in to ensure all cars are in the same state when the test commences.

What Car? Real Range: how we work it out

Real Range testing

The following morning, tyre pressures are checked and adjusted to ensure they match the manufacturer’s recommendations.

What Car? Real Range: how we work it out

Real Range testing

The driving part of the test is only conducted when the ambient air temperature is between 10 and 15deg C.

What Car? Real Range: how we work it out

Real Range testing

Tests are always conducted with a driver and front passenger, or with the car ballasted accordingly.

What Car? Real Range: how we work it out

Real Range testing

Using the car's pre-conditioning function (if available), the interior temperature is primed to 21deg C while the car is still plugged in.

What Car? Real Range: how we work it out

Real Range testing

The climate control is set to 21deg C for the remainder of the test and the headlights are switched on.

What Car? Real Range: how we work it out

Real Range testing

If the car has multiple driving modes, ‘normal’ is selected, along with the standard level of regenerative braking, or the lowest if no standard mode is available.

What Car? Real Range: how we work it out

Real Range testing

All driving is done at What Car?’s private test track, so traffic conditions don’t affect the result. However, the 19.4-mile route simulates a mix of stop-start urban traffic, rural roads and motorways. This route is driven twice for cars with batteries that accepted more than 60kWh during the preparation stage and three times for cars with batteries that accepted more than 100kWh.

What Car? Real Range: how we work it out

Real Range testing

Consistent driving is ensured by the use of a Racelogic Speed & Route Profiler, which allows the route to be repeated again and again with a very small variance. 

What Car? Real Range: how we work it out

Real Range testing

At the end of the test, the car is plugged back in and the energy required to return its battery to full is measured.

What Car? Real Range: how we work it out

Real Range testing

Knowing the kWh required for the test route and for a full recharge from flat enables us to calculate the Real Range.

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