The driver plays a vital role in the care and feeding of $5,000 worth of rubber.
Many longhaul carriers are not coming to grips with driver behavior that adversely affects tire costs. In fact, it's not uncommon for these carriers -- who've been so desperately short of drivers lately -- to overlook certain driver habits, which, while not grossly abusive of tires, can have a negative effect over time.
According to information obtained during Goodyear fleet focus meetings, there's a great deal of difference in the way truckload drivers operate equipment, as well as how they treat the tires.
For example, tread life can vary by as much as 30% from one rig to another. According to the Goodyear data, some drivers average 2 retreads from casings, while others average only 1.5.
On a per-truck basis, such a disparity can be very significant. For example, if Driver A averages 150,000 mi. before the tire-removal stage, his tire cost comes to 2 mils/mi. (based on a cost of $300/tire). Driver B, who averages 200,000 mi. on a set of tires, will have a cost of 1.5 mils/mi., which represents a 25% decrease.
At 120,000 mi./yr., Driver A's annual per-tire cost is $240, or $4,320 for 18 tires. Driver B's per-tire cost is $180, or $3,240 for 18 tires. The difference is $1,080 -- the equivalent of more than three brand new tires. A 100-tractor-trailer fleet with a cadre of Type A drivers is going to pay an extra $108,000 in tire costs.
What are the differences between the two types of drivers? There are several. Type A drivers use excessive speed, hard braking, fast cornering, and tire curbing, all well known enemies of tire life. Consequently, the kinder, gentler habits of Type B drivers mean better fuel economy and lower tire cost per mile (cpm).
Another important difference is the driver's behavior when he's not behind the wheel. How drivers take care of their tires and how frequently they check inflation levels can both affect tire cpm.
Since the air inside the casing supports the load, regular inflation pressure checks should be a top priority for drivers. Too much pressure -- or for that matter, too little -- can cause problems. Too much air will result in tire bounce and irregular wear. A tire that is 15% under-inflated will get 8% less tread mileage, and it can wear irregularly. Under-inflation can also cause excessive flexing, producing unwanted heat and thus reducing the chances of successfully retreading the casings.
Good inflation control on the road means regularly using a good tire gauge -- one that has been calibrated from a good Master gauge. Drivers should be trained to use the gauge to check pressures on all tires, not just the steers. Trailer tires are probably the most neglected of all, but they, too, must be gauged. A good driver should be able do all this in about 10 min., provided the valve stems are equipped with flow-through caps.
Careful drivers also look for signs of misalignment, which shows up as irregular and very fast shoulder wear. "Fingertip diagnosis" is really not that difficult. By running their hands across the tire surface from bead to bead, drivers can detect bumps, ridges, or resistances that do not belong there. This tactile early-warning system can alert drivers that it's time to check for misalignment.
The most frequent cause of chunking on the outside shoulder rib is running over curbs and potholes. While checking tread, drivers can also inspect sidewalls, looking for tears and snags in particular. But while tread damage can often be repaired, injured sidewalls cannot.
It all comes down to education. If you haven't incorporated a driver's tire program into your safety program, it's time you did. Today's tires are high-tech composites with dozens of different components. By showing drivers tire cross-sections, training them in the basics of visual inspection, and stressing the importance of regular airing, you can save your fleet lots of tire money.
