Tire pressure determines the shape and contact area of the tire on the road. If the pressure is too low; the tire deforms more and has a larger contact area.
This results in higher rolling resistance, higher fuel consumption, uneven wear and overheating of the tire.
The tire also loses stability and grip, resulting in poor handling and braking. In the worst case, underinflation can cause the tire to burst or slip off the rim.
WHY IS PROPER TIRE PRESSURE SO IMPORTANT?
When tire pressure is too high, the tire deforms less and has a smaller contact area. This results in lower rolling resistance and fuel consumption, but also uneven wear and poor tire grip. In addition, driving comfort suffers because the tires are less able to compensate for uneven road surfaces. In the worst case, overinflating can cause the tire to burst.
The correct tire pressure is therefore a compromise between rolling resistance, fuel consumption, wear, grip, driving comfort and safety. It depends on several factors such as vehicle type, tire type, load, speed and outside temperature.
HOW DO I DETERMINE THE CORRECT TIRE PRESSURE?
The correct tire pressure for a vehicle is specified by the manufacturer and may vary depending on the front and rear axle. The correct tire pressure can be found in different places, such as the owner’s manual, on the B-pillar when the driver’s door is open, on a sticker in the glove compartment, or on the inside of the fuel filler cap, depending on the vehicle. You can also find tire pressure charts from manufacturers on the Internet.
Tire pressure is measured in bars. It is customary to indicate the excess pressure over ambient pressure rather than the absolute pressure. A tire pressure of 2.7 bar therefore, means that the tire pressure should be 2.7 bar above the ambient pressure of approx. 1 bar.
The correct tire pressure always refers to the “cold” tire. This means that the tire has not warmed up due to a longer or faster ride. This is because the air in the tire expands as it warms up and the pressure increases. Therefore, the tire pressure should be checked before starting a trip or after a short ride at moderate speed.
HOW DO I CHECK MY TIRE PRESSURE?
To check your tire pressure, you will need a tire pressure gauge. This can be a handy digital or analogue pressure gauge, which you can buy at a speciality shop or online. You can also use a tire pressure gauge at a gas station or auto repair shop to check your tire pressure. Make sure that the gauge is calibrated and suitable for the pressure range you want to use.
To measure the pressure, first remove the valve cap from the valve of each wheel and press the gauge firmly on the valve. As little air as possible should escape. The gauge will now show the current tire pressure. Compare this with the manufacturer’s recommended tire pressure and keep track of the difference if needed. Repeat for all four wheels.
HOW DO I INFLATE THE TIRE PROPERLY?
To inflate the tire, you will need a suitable source of compressed air. This can be a compressor you have at home or in a garage. You can also use an air station at a gas station or repair shop. Make sure that the air source is calibrated and suitable for the desired pressure range.
To inflate the tire, first unscrew the valve cap from the valve of each wheel and press the air gun firmly onto the valve. As little air as possible should escape. The air gun will then display the current tire pressure. If the pressure is too low, pump air into the tire with the air gun. When the tire pressure has reached the manufacturer’s recommended value, release the air gun and pull it off the valve. Then screw the valve cap back on the valve. Repeat this procedure for all four wheels.
If the tire pressure is too high, deflate the tire. You can do this by pressing the tip of a ballpoint pen or another suitable object into the valve to open it. Be careful not to release too much air at once. Check the tire pressure with a pressure gauge and adjust if necessary. Screw the valve cap back onto the valve. Repeat for all four wheels.
HOW OFTEN SHOULD I CHECK MY TIRE PRESSURE?
Tire pressure should be checked regularly and adjusted if necessary to ensure the safety and performance of the vehicle. Check the tire pressure with a tire pressure gauge and adjust if necessary. In addition, tire pressure should be checked before long trips, when there are large temperature fluctuations, when the load changes, or when changing from summer to winter tires.
WHAT ARE TIRE PRESSURE MONITORING SYSTEMS?
Tire Pressure Monitoring Systems (TPMS) are electronic systems that monitor tire pressure while a vehicle is in motion and alert the driver to low tire pressure. As of 1 November 2014, TPMS is mandatory for all new vehicles in the EU. There are two types of TPMS: indirect and direct.
Indirect TPMS uses the vehicle’s anti-lock braking system (ABS) to measure the speed of each wheel. If one wheel is under-inflated, it will spin faster than the others. The system detects this misalignment and alerts the driver via a dashboard display.
With direct TPMS, sensors in each wheel measure the air pressure and temperature in the tire and send the data wirelessly to a control unit in the vehicle. The system displays the current tire pressure at each wheel and warns the driver if the tire is under-inflated or overheating. TPMS are useful tools that can improve safety and prevent damage. However, they do not replace regular tire pressure checks with a proper gauge, as they are not always accurate or timely.
THE BOTTOM LINE
Proper tire pressure is an important factor in the safety and performance of a vehicle. It should be checked regularly and adjusted if necessary to achieve an optimum balance between rolling resistance, fuel consumption, wear, grip, ride comfort and safety.
Tire pressure monitoring systems can help detect and report a loss of pressure while driving, but they do not replace manual checking with a proper gauge.
Compensate for uneven road surfaces. In the worst case, overinflating can cause the tire to burst.
The correct tire pressure is therefore a compromise between rolling resistance, fuel consumption, wear, grip, driving comfort and safety. It depends on several factors’ such as vehicle type, tire type, load, speed and outside temperature.