Many accidents are caused by underinflated tyres. If you’re not doing it already, it’s time to start checking your tyres every month. You’ll be saving money, and you could save lives.
Isn’t once every few months enough? No, it isn’t. There are many reasons why you need to check tyre pressure every month.
Tyre pressure is crucial for safety, fuel efficiency, and tyre longevity. It dictates how your tyres interact with the road. Proper inflation ensures optimal grip and braking, while also enhancing ride comfort.
Tyres wear out faster if they’re underinflated, and they wear irregularly if they’re overinflated, so in both cases you’ll need to buy new tyres more often. Proper care stabilises the tyre structure and can extend the average life of a tyre.
You’ll also save on fuel: If the tyres are underinflated, the vehicle will consume more fuel or energy per mile traveled, and thus achieve lower mileage.
Properly inflated tyres influence the responsiveness of the vehicle, and its handling and performance.
If tyres are under or overinflated, handling is affected. It becomes sluggish if the tyres are underinflated, and dangerous if they’re overinflated, especially if you’re cornering at high speed. Stopping distance, braking grip, and directional stability are all affected. As your tyres struggle to stay on the road, heat builds up, making blowouts more likely and increasing the risk of a serious accident.
If your car’s tyres are underinflated by just 0.3 bar, rolling resistance is increased, so your vehicle will consume about 1.5 percent more fuel and therefore release more CO2. Proper inflation means a perfect balance of maximum safety and fuel or energy economy. Your tyres will last longer and you’ll reduce your carbon footprint.
Tyre pressure is expressed as kPa, or Bar or pounds per square inch (PSI). It’s based on a vehicle’s weight and size, and it’s important to use exactly the pressure that’s recommended for your vehicle by the manufacturer. This will ensure safety and optimal performance.
Check the pressure every two to four weeks, and always before setting off on longer journeys or if you’re carrying additional loads.
Identify the manufacturer’s recommended pressure for the front and rear tyres of your particular vehicle and tyre size. This is the minimum amount of air pressure needed in cold tires to support your vehicle. You’ll probably see two figures, one for normal use and one for full loads.
You’ll find this in the vehicle handbook in the car, inside the fuel filler cap, or on the driver’s door jamb. If you can’t find it, consult your vehicle retailer, manufacturer, or qualified tyre professional.
Check the tyre pressure before you start driving to ensure an accurate reading.
Use a reliable, accurate tyre pressure gauge either at home (you can buy one at an auto parts dealer) or at a petrol station..
Remove the end cap on the tyre’s air valve and keep it safe. Place the gauge onto the valve stem and press down quickly and firmly until the hissing sound of air escaping stops. Your gauge will now show a reading of the PSI, or kPa or Bar. Compare this with the manufacturer’s recommendation.
If the reading is above the recommendation, push in the valve to let out some air. You may have to do this a few times until the gauge shows the correct reading. If the PSI reading is below the recommendation, use an air compressor to fill the tyre with air until it has the correct level. Replace the valve cap tightly and repeat the process with the three remaining tyres, plus the spare tyre.
These two numbers should not be mixed up, since they serve completely different purposes.
Manufacturer-recommended tyre pressure: This is the number found on the sticker inside your driver’s side door jamb. It is calculated by the car's engineers to provide the perfect balance of safety, fuel economy, and ride comfort for your specific vehicle weight. This is the number you should follow.
Maximum pressure on tyre sidewall: This number is molded directly into the tyre rubber. It is not a recommendation but a structural safety limit, since it tells you the absolute maximum pressure the tyre can hold before it risks failing. Driving at this pressure will result in a stiff ride and poor traction.
Before looking at the different units used to measure tyre pressure, it is important to understand that the recommended pressure can be expressed in several formats depending on the country, vehicle manufacturer, or tyre pressure gauge. The three most common units are PSI (pounds per square inch), kPa (kilopascals), and bar. Although they use different scales, they all measure the same thing: the amount of air pressure inside the tyre. Knowing how these units relate to one another can help you correctly interpret tyre pressure recommendations and ensure your tyres are inflated to the proper level.
PSI is the most widely used unit for measuring tyre pressure in countries that follow the imperial system, such as the United Kingdom. The abbreviation stands for “pound-force per square inch”. PSI is defined as the pressure created when a force of one pound-force is applied to an area of one square inch. One PSI is approximately equal to 6,895 pascals (N/m²).
It is a versatile unit that can be used to measure various types of pressure. If you live in a country that uses the imperial system and purchase a vehicle from a country that uses the metric system, you will likely need to convert tyre pressure readings from bar or kPa to PSI.
Bar is a metric unit of pressure used in countries that use the metric system. One bar is equivalent to 14.50 PSI. Compared to kPa, bar is considered a less precise and less scientific method for measuring pressure.
kPa stands for kilopascal, a metric unit equal to 1,000 pascals. Because pascal is a relatively small unit, tyre pressures are typically measured in kilopascals for convenience.
It is widely used as a unit of pressure measurement around the world, especially in countries that follow the metric system, such as most of Europe. In many industries, kPa is gradually replacing PSI as the standard unit for pressure measurement. One kPa is equal to 0.145038 PSI.
Maintaining the right tyre pressure is more than just avoiding a warning light; it’s about how your car handles the road. Here is what happens when you stray from the manufacturer's recommended tyre pressure:
Tyre pressure is not a fixed value and can change over time, even if your tyres are in good condition. Several factors can influence the amount of air pressure inside a tyre, affecting vehicle handling, tyre wear, fuel efficiency, and overall safety.
When air molecules are exposed to cold temperatures, they move more slowly and cluster closer together, which causes them to occupy less physical space. In contrast, air molecules in warmer temperatures move more rapidly and spread farther apart, occupying more space.
As the air inside your tyres heats up, the molecules expand, which typically leads to an increase in tyre pressure. Conversely, when the temperature drops, the air inside your tyres contracts, causing a decrease in tyre pressure.
In short:
Heavy loads require higher tyre pressure to prevent heat buildup and support the weight on the vehicle.
Leaks from punctures or debris like nails or screws in the tread will cause tyre pressure loss.
If you drive an electric vehicle, monitoring your tyre pressure is even more important for maximizing your car’s performance and range.
Protect your range: Underinflated tyres increase rolling resistance, forcing your motor to use more energy. Keeping your tyres at the correct pressure can extend your driving range by up to 15% per charge.
Support extra weight: Because of their heavy battery packs, EVs are often 20% to 30% heavier than comparable combustion engine cars. This extra weight requires bigger tyre sizes and higher tyre pressures to maintain the tyre’s structural integrity and and ensure the tres can safely carry the higher load.
Manage instant torque: EVs deliver maximum power to the wheels instantly. Proper inflation ensures the tyre’s contacty patch is optimised to handle this instant torque, reducing micro-slippage and preventing premature tread wear.
Continental has developed a Tyre Pressure Monitoring System (TPMS) that works with wheel sensors and brake systems to alert the driver to low tyre pressure levels, via a dashboard warning light.
This invaluable safety feature also helps reduce fuel consumption as well as CO2 emissions and increases your car’s optimal performance lifespan.
However, even if your vehicle is equipped with a TPMS, you still need to check tyre pressure every two to four weeks, to ensure a better, safer driving experience.
Inflating your tyres to the minimum recommended pressure may result in a softer ride, but it can also cause increased tyre wear, reduced fuel efficiency, and less precise handling. Underinflated tyres are more prone to overheating and damage, especially when carrying heavy loads or driving at high speeds.
Inflating tyres to the maximum pressure listed on the sidewall can make the ride harsher and reduce traction, especially on wet or uneven surfaces. Overinflated tyres wear out faster in the centre, are more susceptible to impact damage, and may compromise safety and comfort.
Proper tyre pressure reduces rolling resistance, helping SUVs achieve better fuel economy. Underinflated tyres increase resistance, causing the engine to work harder and consume more fuel. Keeping tyres at the recommended pressure can save money and reduce emissions.
Check tyre pressure at least once a month, as well as before long trips or heavy loading. Commercial vans often carry varying loads, so regular checks help maintain safety, performance, and tire longevity.
The tyre pressure warning light indicates that one or more tyres are significantly under- or overinflated. This can be caused by temperature changes, a slow leak, a puncture, or recent tyre service. Check all tyres promptly to ensure safe driving.
Inflate all tyres to the recommended PSI. Consult your owner’s manual for the reset procedure – some vehicles require pressing a reset button or using the dashboard menu.
For winter tyres follow your vehicle manufacturer’s recommended pressure, which is usually listed in the manual. In colder weather, tyre pressure drops, so check and adjust it regularly to maintain optimal grip and safety.
Tyres should be inflated to the recommended pressure for your vehicle. Some vehicles specify different pressures for front and rear tyres. However, large differences can affect handling, safety, and wear. Always follow the manufacturer guidelines.
Yes, tyre pressure naturally increases as tyres warm up during driving due to heat expansion. Always check tyre pressure when the tyres are cold for the correct reading.
