Original submission by T Apr 27th 2007:
Why is US traffic slowing down? The cars are all tired.
This is a joke of course. In the US they spell car tyres "car tires". It's a wonder they haven't tired of it by now.
The Effect of Temperature on Tyre Pressure:
Tyre pressure changes with the temperature of the day. When the temperature falls so does the tyre pressure.
When the temperature rises so does the tyre pressure.
As the winter season starts, a weekly check of tyre pressures will show them to be falling. In the middle
of winter the pressure will stabilise. As summer approaches the tyre pressure can increase.
Checking Tyre Pressure:
Tyre pressures should be checked before the car is driven for the first time that day or as soon as possible afterwards.
The process of driving the car heats the tyres and causes the air inside to expand. Checking the pressure
of a tyre immediately after a lot of driving will show a higher pressure than when the tyres are cold.
Manufacturers state the figures and conditions under which they recommend tyre pressures should be set.
Often they will have one figure for city driving and another for open road driving. It's wise to follow their
The Importance of Tyre Pressure:
The pressure of the air in the Tyre determines the nature of the Tyre which in turn determines the way the car will drive.
If the Tyre Pressure is Too Low:
If the pressure is too low the Tyre will be soft and spongey giving poor handling response and directional control.A Tyre whose pressure is too low can have undesirable handling characteristics especially in the wet.Too low a pressure will cause the Tyre wall to flew which can become so bad at highway cruise speed I've seen it set a Tyre on fire.It will also increase Fuel Consumption.
If the Tyre Pressure is Too High:
If the pressure is too high the car will ride hard and bumps will shock through the vehicle in an unacceptable manner.A Tyre whose pressure is too high can have undesirable handling characteristics especially in the wet.Too high a pressure can cause the Tyre to blow-out at highway cruise speeds due to the excess of pressure and heat build up.