Tires have two basic functions: they contact the road, and together with rims, they hold pressurized air inside them. That air is necessary to absorb incoming shocks, keep tires firm yet flexible and, most importantly, it carries the load. Except for some futuristic models of non-pneumatic (airless) tires and Run-on-Flat technology, tires without highly pressurized air inside will barely be able to bear their own weight.
It is neither the tire itself nor the rim that carries the load of the vehicle, driver, passengers and any load – it is the compressed air that is responsible for getting the job done. Maintaining proper air pressure is therefore crucial for safety, performance and durability. It will vary depending on temperature, changing with seasons, and decrease over time as tires, which are made of rubber that is not impermeable, will leak air over time. It is dangerous to assume that once the mechanics installed the tires, the pressure in an undamaged tire will just be fine. The tire will gradually lose pressure even if it is demounted and in storage.
Low tire pressure
Pressure has to be checked regularly. You may find various methods online teaching how to do it without a gauge – we do not recommend following them. Especially the so-called “eyeball method” refers in essence to adding air and checking if the tire looks properly inflated. Tire pressure gauges are not expensive and will provide an accurate reading.
How to use a tire pressure gauge
Electronic tire pressure gauge
All depends on the type of the tire pressure gauge you have. The pencil-style ones are cheap and very compact. Digital ones are slightly more expensive and require batteries, but will reward you with an accurate reading and some models are equipped with a back light that will help check the reading in the dark. Another advantage of digital pressure gauges is that some models allow more than one pressure scales and provide a reading in PSI, bar, KPa or Kg/cm2. Finally there are dial gauges – equally accurate, but bulky and often even more expensive, they are more resistant to damage or other malfunctions and do not require batteries.
Check the pressure when the car has been in stop for some time. Tires generate heat as they roll, and this will cause the air inside them to expand. Apart from that, take ambient temperature into account – in cold winter, the air will contract, but in summers - the reading will be higher.
To measure the pressure, first remove the cap from the valve stem. Enter the gauge and press it evenly. You should be able to acquire a reading at this point. If you hear the hissing noise of escaping air, make sure you adjusted the gauge correctly.
What is the correct tire pressure?
You know how to check the pressure in your tires, but how do you interpret the readings? The nominal tire pressure can be checked in the car owner’s manual, but apart from that, you will also find it on a sticker on the inside of the driver’s door.
What are the consequences of incorrectly inflating tires? Overinflated tires have less contact area with the road, which will not only have an impact on performance, but also decrease the lifetime of the tire by causing uneven tread wear – the central part of the tread will wear much faster than the sides. The opposite happens when tires are underinflated, the sides wear more than the center, and apart from that, increased heat generation may lead to tire failure. Maintaining the correct pressure will therefore not only guarantee a comfortable ride and maximum performance, but your safety as well.