Summers are getting hotter in the UK, with temperatures regularly hitting 30°C, and heatwaves becoming more frequent. While this is great news for beachgoers and kids on their six-week summer break, it isn’t ideal for our cars or for the people driving them.
During severe heatwaves, vehicle breakdowns jump by 20% nationwide, with that figure climbing to 30% along the coast as drivers head to the beaches, equivalent to more than 1,000 vehicles per day. For this reason, it’s critically important to go into summer prepared for the warm weather rather than being caught out by a sudden spike in temperatures.
Despite modern cars being built to withstand extreme changes in temperature, prolonged exposure to either freezing or sweltering conditions always has the potential to cause some problems. In the height of summer, when cars have to work in hot, dry conditions for weeks at a time, this can impact on performance and safety – so it’s important to keep on top of their maintenance and upkeep.
But what exactly does hot weather do to your car, and how can you prevent damage and performance problems? In this guide, we look at the impact heat can have on cars and what can be done about it.
Do cars struggle in hot weather?
It can be easy to neglect your car’s upkeep in the summer. After all, isn’t winter supposed to be the toughest season for drivers? While this is true, sticking to a regular maintenance regimen in the summer is essential, and here’s why.
For instance, did you know you’re 20% more likely to get a puncture when it’s hot? And clutch problems are more common, too, with extreme heat causing additional wear and tear.
Serious stuff, then. But thankfully, there are things you can do to lessen the impact of heat on your car and keep it performing at its best in spite of the soaring temperatures. Below, we take a closer look at how different parts of your car are affected by hot weather and provide tips on how to prevent problems that could put a real downer on your summer.
What happens if my car overheats?
Combustion engines, whether petrol or diesel, are incredibly hot when running. After all, they’re literally turning explosions into propulsion, but through clever engineering, they’re cooled to acceptable temperatures. Unfortunately, when this engineering fails, or proper maintenance is neglected, and high atmospheric temperatures are added to the mix, your vehicle’s engine can struggle to cool itself, and the car will overheat.
These issues can go unnoticed, but they will rear their heads during periods of heavy traffic when you’re moving slowly and there isn’t enough air hitting the radiator to cool it down. In a car with healthy levels of coolant, this isn’t an issue, but if coolant is missing or isn’t being moved around adequately, you might find your car’s oil gauge dial climbing.
If you notice that your car is overheating, you should immediately pull over, turn off the engine and let it cool for at least 10-15 minutes. Use this time to assess what the issue could be: is there steam or smoke, are coolant levels adequate, are belts and fans in working order?
From here, you should take your car to a mechanic as soon as possible to avoid further damage.
Which areas of the car are prone to problems in the heat?
Battery
While cold weather is punishing on car batteries, the heat of summer can take its toll, too. Very hot weather can hinder the chemical processes inside car batteries, meaning they can struggle to hold charge and produce enough power. This problem is made worse by the increased load from the air conditioning system, fans, windows and electrically-operated convertible roofs – meaning that some batteries can struggle to cope during prolonged spells of hot weather.
Solution – It’s a good idea to get your car serviced before summer kicks off; that way you’ll know that everything’s in good working order before the hot weather arrives. If you miss the early-summer window, get yourself a voltmeter and check the power output of your car’s battery, or have a mechanic do it for you. This will give you an idea of the health of your battery, so you can either replace it or charge it and avoid any problems going forward. It’s also a good idea to take a set of jump leads on longer trips, especially if you drive an older car whose battery might be getting tired.
Cooling System
Car cooling systems have to work much harder in severe weather, both when it’s very warm and when it’s freezing cold. Their job is to keep the engine working at the right temperature, so when it’s hot, they’ve got a lot more work to do.
Cooling systems rely on coolant/antifreeze to keep all parts of the engine cool. On very hot days, the cooling system must work harder to remove excess heat from the engine. If coolant levels are low or a cooling-system component isn’t working properly, the engine may become more susceptible to overheating. Cooling system problems are more likely to happen during low-speed driving, during slow-moving traffic, when there is less natural airflow through the radiator and the cooling fan must work harder to maintain engine temperature.
Solution – Make sure your cooling system is topped up with high-quality coolant/antifreeze. Prestone Coolant/Antifreeze is tested in extreme conditions, and has a high boiling point which makes it ideal for summer driving. Car engines normally run at an optimum temperature of around 90°, but can run hotter in warm weather. That’s why it’s important to have a coolant/antifreeze that offers boil protection.
You can check the current protection level of your coolant/antifreeze with a coolant tester. This lets you know the concentration of coolant/antifreeze in the mix, so you know that your car’s protected.
Tip – if you’re unlucky enough to experience an overheating engine, read our guide on how to stop it and what to do.
Tyres
Car tyres and hot weather don’t get along. That’s because the heat makes the air inside expand, causing tyre pressures to increase. If tyres are already damaged, worn or incorrectly inflated, this additional stress can increase the risk of tyre failure. On average there are around 300,000 tyre-related breakdowns every year, and many of these happen in the summer months when people are unaware of their tyres being set at the wrong pressure.
Solution – Get in the habit of checking your tyre pressure every fortnight, or more regularly if you drive a lot or have a big journey coming up. The effects of prolonged hot weather mean your tyres could be a few PSI over the recommended pressure, putting you at an increased risk of a blowout – which is never fun.
Engine Oil
When your car’s running hot in the summer, engine oil naturally becomes thinner as temperatures increase, but modern oils are designed to provide protection across a wide operating range. However, old or degraded oil may provide less effective protection during prolonged periods of high engine temperature. This can mean that some parts of the engine don’t get the protection they need, resulting in increased friction and the potential for engine damage.
Solution – It’s a good idea to change your car’s oil just before summer, replacing the old fluid with a high-quality, summer-ready alternative. Always ensure the oil level remains within the manufacturer’s recommended range between the minimum and maximum marks on the dipstick.
Air Conditioning
Most cars now come with air conditioning as standard, which is great news for us when the summer hits. The thing is, if you don’t maintain your car’s a/c system throughout the year, it might not have the power to cool you down when the temperatures really start to climb.
Air conditioners need regular maintenance to keep them working at their best. Air conditioning performance can deteriorate over time due to factors such as refrigerant loss, dirty cabin filters or normal system wear.
Solution – Get your car’s air conditioning system serviced in time for summer. A professional mechanic should be able to do this for you. Follow the service intervals recommended by your vehicle manufacturer and have the system inspected if cooling performance noticeably declines.
Tips for driving in hot weather
Driving in hot weather doesn’t need to be a hassle; with just a few tips, driving during a heatwave can be a perfectly pleasant experience.
Use the correct settings on your air conditioning
When first entering a very hot vehicle, open the windows briefly to let hot air escape. Once the cabin begins to cool, using the recirculation setting can help the air conditioning work more efficiently.
However, once the car is at a comfortable temperature, you should turn recirculation on so that the cool, dehumidified air being made by your air conditioning isn’t being diluted by the air outside. This will also reduce the load put on your A/C compressor, giving your MPG a (small) helping hand.
Park in the shade
Parking in shade prevents your car from reaching the high temperatures it otherwise would if it were left in direct sunlight. This can ease the burden on your A/C and also help to reduce wear on upholstery from sun bleaching.
Make sure there is water in the car
You never know how long you’re going to be in the car, particularly on long journeys, when traffic jams are all too common. For your safety and your passengers’ safety, it’s a good idea to always have water in the car. It’s an inexpensive way to make sure that everyone is hydrated and doesn’t overheat during hot weather.
Ensure air con is serviced and in good working order
Summertime during a heatwave is the worst time to find out that your air conditioning isn’t working properly. Before summer hits, you should try to get your air conditioning serviced and regassed, if necessary. Alternatively, you should make sure that your air conditioning is working properly before any long journeys, such as a long commute or staycation.
The heat of summer may be tough on our cars, but with the right maintenance and products, you can prevent problems and enjoy a happy season of driving. For more tips and advice on taking care of your car, any time of year, visit the Prestone website today.