Through the “Key safety checks part 1” module in level one you should now be fully aware of the main factors which effect tyre performance. We will now explore the impact if some of these elements of tyre performance are not at their optimum levels; as well as looking at the concept of rolling resistance.
Under or Over Inflation
Tyres that are under inflated or over inflated can affect your tyre life, driving comfort, traction and braking.
Under inflation generates excessive flexing of the tyre casing, which results in overheating, increase of rolling resistance (which will be explored further later) and premature wear.
In extreme cases, under inflation can cause tyre damage. Likewise, over inflation can reduce tyre life, reduce grip and create irregular wear.
Having your tyres correctly inflated not only optimizes performance, but also leads to increased safety.
Ignoring this advice runs the risk of decreasing your grip and increasing your braking distances. You could also damage your tyres reduce their lifespan and increase your fuel consumption.
If your tyres are over or under inflated enough to be considered un-roadworthy, reading this module could save you a fine of up to £2,500 per tyre.
A tyre which is 20% under- inflated can give 20% less mileage. That means a possible loss of 5,000 miles (8,000 km) on a potential mileage of 25,000 miles (40,000 km).
Driving with incorrect tyre pressures can affect a vehicle’s handling, and can seriously compromise safety—leading to incidents that can put lives at risk. A correctly inflated tyre improves safety, is more economical in use and is better for the environment.
What is rolling resistance?
At every turn of the wheel the tyre tread area bends and deforms as it comes into contact with the ground and then moves away from it.
As the rubber deforms it gives out energy in the form of heat. This is the source of 90% of the tyre's 'rolling resistance'. The heat is basically energy lost that could be driving your car forward.
The more rolling resistance a tyre has, the more power is required from the engine to move the car along. If the engine has to work harder just to overcome the tyre's rolling resistance, it will use more fuel.
20% of a car’s fuel consumption, or 1 tank in 5, is used to overcome tyre rolling resistance (on average).
What’s next?
In the next section, we explore some additional safety checks that you can make. Specifically, we take a look at some of the common wheel based issues that your local tyre dealer or mechanic may discuss with you.
Whilst you don’t necessarily need to understand the absolute detail, it’s useful to understand what they are doing with your vehicle so that you can make a more informed decision.
