Nobody wants to sit in the cold in freezing temperatures. But unlike cars with combustion engines, electric cars cannot use the waste heat from the engine for heating, but have to draw the energy required for this from their drive battery. The consumption is at the expense of the range. Efficient heating is therefore quite important in e-cars.
The ADAC examined the heat output of seven e-cars from different vehicle categories. It looked at how long the vehicles needed to heat up their interior and how long they can retain the heat. The models Fiat 500e, Renault Zoe, VW e-Up, Hyundai Kona Elektro, VW ID.3, Tesla Model Y and BMW iX were tested.
At an ambient temperature of minus 10 degrees in a cold chamber, the automobile club had the heaters in the seven vehicle models heated to an interior temperature of plus 20 degrees. Within a short time, almost all of the tested vehicles blew out air that was around 20 degrees warm, and after five minutes the air blown out was almost 40 degrees warm. Electric cars have a clear advantage here over combustion engines, which initially depend on the engine heating up to the point where sufficient waste heat can be generated for the heating system.
The models tested required an average of 1.5 to 2.3 kWh of energy to heat the vehicle interior to +20 degrees. The most economical here were the Hyundai Kona Elektro and the Fiat 500e, each with 1.5 kWh, closely followed by the Tesla Model Y with 1.6 Wh. The BMW iX was 2.0 kWh, the VW ID.3 had the highest value with 2.3 kWh of energy. This means that the energy consumption of the heaters is at least so low that you could even spend a whole night in a traffic jam with the heater switched on - provided the drive battery is not already largely discharged beforehand.
The study revealed "surprisingly large differences," it says. The BMW iX took 12.5 minutes, while the VW ID.3 and the Hyundai Kona Elektro took around 25 minutes. The Fiat 500e took just over 30 minutes. The other models (Fiat, Renault, VW e-Up and Tesla) could not bring the interior to a temperature of 20 degrees even after 40 minutes. The Tesla Model Y, for example, only managed a maximum temperature of 15 degrees. One reason for the weak heating output is the partly economical installation of air nozzles.
The ADAC then tested the thermal insulation of the vehicles. To do this, the engineers of the automobile club let the interior cool down with the heating switched off and an outside temperature of minus 10 degrees. Here, too, the BMW model performed best: after 30 minutes, temperatures of around 10 degrees were still measured inside the vehicle. The SUV owes this to its apparently good insulation. After the same time, it was still 9 degrees in the VW ID.3, 8 in the Fiat and 7 in the Hyundai.
The three remaining models, which had not managed to bring their interior to a temperature of 20 degrees in the first test, started the second test with a lower interior temperature. After only five minutes, the temperature in the Tesla and Renault was only 10 degrees, in the VW e-Up it was still 8 degrees. After 30 minutes, it was still 5 degrees in all three models.
Although the test is not representative of all electric cars, the ADAC examined vehicle models from various categories in order to be able to create as broad an impression as possible. After all, energy efficiency is the be-all and end-all when it comes to e-cars, because low power consumption has a positive effect on the range of the vehicle.
According to the automobile club, there is still room for improvement in terms of thermal insulation. In addition, drivers should be aware that frequent short trips in winter reduce the range of the vehicle. Eventually the car cools down and the interior has to be reheated after a stop.
The ADAC therefore recommends using the seat and steering wheel heating in winter and opening doors and windows as briefly as possible. In addition, if possible, you should park your electric car in warmer environments such as a garage to reduce heat loss to the cold environment. It also makes sense to switch on the heating while the vehicle is still charging. And the air vents should be aimed specifically at the driver and the passengers in the back seat. A heat pump like the one installed in the VW ID.3, BMW iX, Renault Zoe and Tesla Model Y does not significantly improve the energy requirements of an electric car.