Keeping your car cool: 10 top tips on air-con, sun screens and driving in summer

According to research by SEAT, a temperature in excess of 35°C inside your car can impair your driving ability by as much as a 0.05 per cent blood alcohol reading. That’s close to the UK drink driving limit of 0.08 per cent. The study showed that these hot temperatures, that can be reached inside a car on hot summer days reduce drivers’ reaction times with the 10°C increase from 25°C to 30°C causing a 20 per cent drop in a driver’s speed of reactions. 

• What is climate control and air conditioning?

It all means that keeping cool in your car during hot weather isn’t just about comfort for you and your passengers. There’s a real safety issue attached as well. To see you through your summer road trips and daily commutes, we have put together some useful advice for cooling your car, and yourself, then keeping it that way… 

10 top tips for keeping your car cool this summer

1. Start your day right

Summer mornings are often cooler, lulling us into a false sense of security for what the rest of the day might hold temperature-wise. Even in those cooler early hours, however, using the car’s air-conditioning will help counteract the rising temperatures as the sun moves higher in the sky. Gradually cooling the car in this way is a far better option than waiting until the car heats up to activate the A/C.   

2. To re-circulate, or not to re-circulate

When you first get back into your car, you can use the recirculation option on your car’s air-con to cool the cabin down. This makes it much easier for the system too cool the air quickly, as it continues to work on the cooler air inside the car. 

However, continually using air recirculation can cause your windows to fog. If you have rear-seat passengers, recirculation can also be a bad idea as many systems pull air from the front of the car and continue to cool it, but the air in the back of the car can quickly become stale and warm. The best option is to use the ‘auto’ mode, which most cars now have. This is self-regulating and works well to keep everyone in the car cool. 

3. Find some shade

We know we’re stating the obvious here but where possible, park out of direct sunlight. It’s also worth thinking ahead here if you’re parking for a whole day, as a shady spot in the morning could be in full sunlight later in the day. 

• Summer road trip: how to prepare your car

If you can, pick a spot that’s going to be shady in the mid-day heat. You should also try to position your car with the sun behind you, as this will keep the steering wheel and front seats cooler. If you work within easy reach of the car park, you could always pop out at lunchtime and relocate your car to a spot with more afternoon shade, it might seem a chore but you’ll be glad you did it on the drive home.

4. Break out the sun screen

When it get’s sunny, it’s always sensible to apply some sunscreen, and your car is no different. You can get relatively cheap reflective screens online or from most good automotive outlets, or if you fancy splashing the cash, you can invest in specialist sun shields that use reflective coatings. Either way, a reflective shield on your windscreen will help to redirect the sun’s rays and keep your cabin cool.

5. Cover-up that leather

If your car has leather seats, a hot day can be particularly uncomfortable. An easy way to keep your seats a little bit cooler is to use a blanket, or whatever you can find, to cover them when the car is parked. The leather seats won’t get quite so hot if they aren’t in direct sunlight. 

If you can’t cover them up, wiping leather seats, steering wheels or the dreaded alloy gear knobs with a damp cloth is a good way of quickly cooling them before driving off.  

6. Release the heat

At the end of a sunny day, you return to your car, knowing that a veritable oven awaits you. All you want to do is crank up the air-con to the max and head home to a nice cold drink. By jumping straight into a hot car and driving off, however, you don’t allow any opportunity for the heat to escape, giving your air-con a much tougher job to reduce the car’s air temperature. The best bet is to wait before getting into your car, opening the doors and windows for a moment to allow the hot air to escape.

• How to demist your windows fast

If you can, it’s good to also leave a small gap in your windows while the car is parked, but only do this if you know your car is secure (and it isn’t going to rain later!).

7. Pre-cooling doesn’t work

Your car’s air-con won’t be as effective before your start driving as the air compressor runs faster when the engine is running. It’s therefore not worth the hassle of pre-cooling your car before you drive off. Instead, it’s better to simply let the hot air out of the car before you get in, then get the air-conditioning into action on route.  

8. Stop the stop-start

Although stop-start can be great for saving fuel, on a really hot day it can reduce the effectiveness of your air-conditioning. When the feature turns off the engine, it also will stop the car’s air-con from running, and if you’re stuck in a summer traffic jam, you’ll notice the lack of A/C pretty quickly. If your car does have this feature, it’s a good idea to turn it off when it’s hot. 

The same also goes for the eco driving modes you’ll find on modern cars. As well as adjusting automatic gearshift patterns and throttle response, many of these systems reduce the effectiveness of the air-conditioning to save fuel. If you want to prioritise your own personal warming over the global kind, turn off the eco mode until the sun goes down.

9. Getting the right angle

After a long, hot day, you might want to feel a bit of cool wind in your hair and it can be tempting to point every available air vent directly at your face. But this actually won’t keep the car cool as effectively because it won’t equally distribute the airflow around the cabin. Instead, it’s best to angle the vents upwards as this will allow the air to spread more evenly around your car, cooling it more efficiently. 

10. Maintenance

Like any other part of your car, looking after the air-conditioning system will make it last longer. Checking air filters every 10,000-15,000 miles is the best way to make sure they aren’t clogged up. On most new cars they are relatively easy to check, and can be found behind the glove box, but if you aren’t sure, your service centre will be able to help. 

Have you got any clever tips to keep cool out on the roads this summer? Let us know in the comments…