Nowadays we prefer to trust car maintenance and repair to specialists care, but car owners still have to check pressure in their cars’ tires manually. Though the popular method of pressure measuring is to press the tire with a finger, it is not reliable at all.
Air pressure in your tires predetermines you car’s performance, its rolling resistance, braking distance, lateral skid and so on, that’s why it should be close to the one recommended by a manufacturer. You can find the exact value in the manual.
On the one hand, underinflated tires cause the degradation of tire handling, quick tread wear and higher fuel consumption. Moreover, you may even cause damage the wheel disk in case of hitting a big pot-hole. On the other hand, overinflated tires increase stress on hub bearings and decrease the threshold of wheel slip, which results in skidding. The recommended value of air pressure helps your tire deliver its best performance while retaining all its features.
Tire pressure checking would be very easy it if were not for such external factors as temperature and loading. The pressure changes together with the temperature, that’s why it is so important to measure pressure before driving. Don’t allow loading to fool you either. If you for instance have the car fully loaded and happen to check pressure on the road its value would be higher than normal. Like every responsible person you decrease its value and as a result your heavy-loaded car goes on underinflated tires, which reduces their mileage and causes higher fuel consumption.
But in fact you don’t need any special knowledge or experience to check pressure in your tires. What you do really require is a precise pressure gauge, or manometer. There are a lot of these devices on the market, but not every one of them can deliver the necessary level checking precision.
So the question arises: how to choose the right pressure gauge. It has been proven that neither price tag, nor origin, nor appearance can determine your choice. But you can check the precision of your pressure gauge at any service center. Ask the service men to inflate your tire to the nominal pressure and then measure it with your own pressure gauge. Service centers usually have precise equipment, so this operation will help you get an idea of possible errors of your own device.
If you don’t have a standard air pressure sensor in your car, you can buy an optional one for no more than $400. The sensor is installed inside the wheel. It measures both pressure and temperature in the tire as the former depends on the latter. The sensor transmits the information to an on-board PC through a miniature radio transmitter and warns you when the pressure is too low. The system features a “friend-or-foe” identification function, so if you meet a car equipped with a similar system, your sensor will still tell you about your own tires. The system can endure acceleration up to 2000 g and works in both low and high temperatures at a circumferential speed up to 190 mph.
Though premium-class cars are equipped with air pressure sensors, the majority of cars on the market are not, so car owners should have their own pressure gauges. To stay on the safe side, you should carefully choose your pressure gauge. A good gauge as well as all pipes should be protected from sub-freezing temperatures. Its limit of pressure measurement should be in the second third of the scale.
Don’t use a pressure gauge if:
- There’s no seal or mark about the latest calibration;
- The term of calibration has expired (Pressure gauges should be checked and calibrated once a year);
- A pointer doesn’t come close to a zero value after you have switched off the device. The deviation should not exceed a half of an acceptable error.
- A glass is broken or a device is damaged in some other way and cannot deliver measuring precision.
Since people are lazybones and are not eager to use pressure gauges too often but still want to control their cars and tires, there exist special indicative valve caps. They can be installed on various types of valves and suit both tubed and tubeless tires, passenger, truck, bus, motorbike, and even bicycle tires. The sensor has differently colored sectors, each of which has its own meaning and carries its own message to a car owner. A green marking says that everything is all right. A yellow sector, if appears, warns you that the pressure is 0.3 atmospheres lower than normal and you should go no faster than 16 mph. A red marking means that pressure has dropped to a critical level and you should immediately stop to inflate your tire.
|
