How to ensure correct tyre inflation

Motor vehicle tyres form part of the suspension system. Finding the ideal tyre pressure makes the ride feel more comfortable and smoother on the road.

All vehicle manufacturers have a sticker somewhere on the car depicting tyre pressure recommended for all suitable tyres that can be fitted on the said motor vehicle. Some cars have the sticker on the passenger side door pillar while others have the sticker inside the fuel cap cover.

Both over inflation and under inflation have a big impact on the suspension and other parts of the motor vehicle systems i.e the steering system and general engine performance.

In today's article, we shall learn about how to correctly carry out tyre pressure checks, the side effects of over inflation and under inflation.

 It is a good practice to check your tyre pressure in the morning when the temperature is still low. One of the basic principles of natural gas states that air increases its pressure when the temperature gets high and reduces when the temp drops. In simple words, your tyre pressure in the morning will most likely give you a correct reading than any other time of the day. For instance, if you wait until you drive for the entire day, on a very hot tarmac road, the chances of your tyre pressure being too much by the time you are taking the readings will be high.

 Further studies show that for every 6°c temperature drop on tyres, at least 1 is lost. The first theory above explains why one would easily get a tyre burst when driving in hot conditions, while the second theory explains why one would seem to have low pressure on almost all the tyres yet no puncture, when driving from an extremely hit area, towards a zone with very low temperatures. 

 All the above conditions can directly cause over-inflation or under inflation without the driver's knowledge. We shall look at each of them and see how they affect the vehicle on the road.

 OVER-INFLATION 

Over inflation is when the tyre pressure exceeds the maximum tyre pressure. The ride becomes too rigid to the extent that every uneven road surface is felt by the occupants. The bump impact is transferred directly to the wheel bearings and any other suspension component within the car. 

  When a car is overinflated, the contact patch to the road becomes so limited because only the centre of the tyre touches the road. This usually leads to difficulty in handling the vehicle on the road due to reduced surface area between the tyre and the road. If this carries on for longer periods, the wear pattern usually only happens at the center of the said tyre leaving the rest of the type with fresh tread. 

  UNDER INFLATION 

Under inflation is the opposite of over inflation, a very large surface area of the tyre especially the edges contact the road more than the center, due to lack of enough air in the tyre. Sometimes this can be brought about by overloading. 

  Under inflation gives the road tyres more surface area hence more grip on the road;  this technique is usually used by racers, stuck vehicles and sometimes when driving on the sand to avoid vehicle sinking. However, on a daily road user, this has a big impact on fuel consumption and tyre wear. Too much surface area means too much friction thus too much resistance which leads to too much fuel consumption and high chances of tyre wear.  

During the rainy season, an underinflated tyre becomes unable to push water from the road 

causing the vehicle to hydroplane thus making it very dangerous to handle in such conditions. Hydroplaning is when the water forms a thin film between the tyres and the road, this causes the vehicle to hoover/glide on the water. under-inflated tyres will always wear on both the edges leaving the center of the tyre with a fresh visible grip. 

  Always have a physical check on your tyres regularly to avoid high costs of maintenance that are brought about by over inflation or under inflation.

The writer owns Boosted Auto repair shop