Tyre Tip 3 - Maintaining Your Tyres

We are all aware of the necessity to operate truck tyres within the recommended parameters of correct inflation pressures, alignment settings, loading, speed, and eventually remove the tyres when the treadwear indicators tell us it's time. But what is the bottom line when these factors are not quite optimum, what does it cost us through not maintaining our tyres?

 

The short answer is, quite a lot.

 

While the tyre manufacturer can extol the virtues of new constructions or innovative compounds to give benefits in treadlife, stability, fuel economy, safety, etc.; you, the truck operator can cause all these attributes to be nullified by simple maintenance negligence.

 

For a start, lets look at tyre inflation pressures. We know that tyres are designed to operate at specific deflections and optimum footprint configurations, with inflation pressures adjusted to achieve this at the various loads.

 

Generally we find that if a tyre is under inflated, this leads to:

• Increased flexing, which causes the tyre to overheat and may cause tyre failure.

• Increased wear, which in turn equals shorter service life. As a general rule if a tyre is run, say, twenty percent under inflated then expect its service life to be shortened by a similar twenty percent.

• Higher rolling resistance and subsequent increased fuel consumption. This twenty percent rule of thumb continues to apply in this aspect as well, so twenty percent under inflation roughly equates to twenty percent increased tyre rolling resistance, which in turn converts to three or four percent decrease in vehicle fuel economy. How much was your annual fuel bill?

• Irregular wear.

While over inflating tyres doesn't have the same deleterious effect as under inflating, it can lead to a shortened service life due to irregular wear and increased vulnerability to impact and staking.

Tread depths, too, can contribute to both the economy and safety of operation. We know the legal minimum tread depth on tyres is shown by the treadwear indicators placed at regular intervals around the tyre circumference. These are 1.6 mm in height and tyres are classified as worn out if below this level. Any further operation of the tyre past this point exposes the casing to a greater chance of penetration damage, thereby raising the possibility of losing retreading capability.

 

Sufficient tread depth is obviously vital on wet roads and braking effects. We know the wet braking distance for a worn passenger tyre with a tread depth of 1.6 mm can be almost twice as long as for a new tyre with full tread depth. Truck tyres may not be as significant as this due to the ground pressures involved, but the principal is the same.

 

So for your peace of mind, and your hip pocket nerve, make sure you maintain your fleet at the correct tyre pressures for your particular operation. Institute an inflation pressure check around every two weeks. Ensure all valves (particularly inner duals) are accessible and operable. Use sealing valve caps. And when a tyre has completed it's first life, remove it early rather than later thus ensuring a satisfactory retread is obtained.