The dogsitting car: How cool is Tesla's 'dog mode' really?

Leaving your dog in the car while running a quick errand on a hot day is a very bad idea.

Five minutes in a hot car are enough for a dog to suffer a heatstroke, the animal charity Four Paws warns. Dogs can sustain brain damage or even die from the heatstroke in just 15 minutes, according to PETA.

Even if the outdoor temperature is relatively low, cars can quickly heat up when parked in the sun. In such instances, panting doesn't help a dog to reduce its body temperature, the activists say.

Leaving your dog inside an EV is less risky as almost all models are fitted with an AC that can be kept running while the vehicle is parked, German motoring organization ADAC says.

Electric car makers Tesla, Smart and Nio have even introduced a feature called dog mode. It doesn't just keep the interior nice and chilled but also displays an alert on the central touchscreen to let passers-by know that your pet is enjoying the AC - so they don't call the police or break through your windows to rescue your dog.

Not cool everywhere

To find out how reliably dog mode really cools your car, ADAC put a Tesla Model Y to the test.

After driving for 8 kilometres, the experts parked the car in a climate chamber heated to 35 degrees Celsius and activated the climate control system's dog mode, which was set to 20 degrees.

They found that the cabin temperature remained stable, even when exposing the car to additional simulated sunlight.

Without using dog mode, the Tesla's interior heated up to almost 40 degrees within 30 minutes, ADAC said. Cracking open the windows didn't help.

However, not every part of the car was cooled equally in dog mode, the experts found.

When exposing the car to additional sunlight, the testers measured temperatures of between 25 and 29 degrees on the rear seat bench and in a dog box in the boot during several simulations.

So if you want to use dog mode, the experts recommend to measure the temperature in the animal's exact location - and lower the AC further if necessary.

Driving an ICE? That's different

Leaving your dog inside a car with an internal combustion engine is trickier, as you need to leave the motor running to operate the AC's compressor.

While there are systems available that are run without the engine that can be fitted retrospectively, those tend to be more suitable for camper vans, the ADAC says.

Plug-in hybrids, on the other hand, are often fitted with electric ACs that can be run while parking, just like in EVs.

The ADAC says, however, that you should only leave your dog inside your car (even if the AC is running) if you absolutely have to - the better option is always to take your pet with you to be absolutely certain that they are safe, the experts say.

Tesla recommends to only use dog mode for short periods of time and while you are nearby "should you need to return to the vehicle in situations where the temperature can no longer be maintained."

You should also monitor the cabin temperature via the Tesla app the entire time.