Bridgestone R&D field engineer Loren Gwilliam looks over some tire evaluation data.

What do you do in your job?

Loren Gwilliam: “Most of the job involves evaluating product performance. For existing products, we check continually to make sure the tires we’re selling are performing to our expectations and also performing well with respect to our competitors’ products.

“Plus, we’re constantly evaluating new products – the next generation of truck tires – as they’re being developed.”

Can’t all this be done on the test track?

“There’s no substitute for the real world. No laboratory or track can duplicate the conditions real trucks encounter.”

What changes as a result of your investigations?

“With products still in development, we’re collecting data that helps the designers devise new patterns, try out new materials, new methods, even new manufacturing processes.

“Prototype products are constantly being evaluated, even when we’ve just introduced a new product.”

Why is that?

“You can’t stop development. If you did, you’d quickly lose your competitive edge.”

What does an evaluation consist of?

“We’ll get a very detailed set of instructions from our engineering department. We then have to figure out the best way, in the field, of getting the data they need.

“We choose the best fleet we can on the basis of a large number of characteristics.”

At the end of an evaluation, it’s vitally important that Bridgestone get its tires back, so they can be examined in minute detail, even dissected, if necessary.

Which is most important of these characteristics?

“Actually, it’s the ‘personality’ of the fleet, their willingness to ‘cooperate’ with us.

“Prototype tires are ours, and it is crucial that we be able to examine them from time to time, and that we be able to get them back at the end of the evaluation so we can do a final review.

“We need to know when we can come examine the tires. That means the fleet has to be able to tell us when a particular truck will be available.

“And, if a tire has been removed, it’s important that they get the tire back to us. It shouldn’t be scrapped or retreaded.”

When you go to inspect tires, what do you look for?

“The most important thing right now is even wear. It’s important that tires wear evenly, so they don’t have to be pulled prematurely.

“This is the primary issue for long distance haulers.”

What procedures do you follow to inspect tires?

“The first thing we do is a careful walk-around. We want to be sure the vehicle is in good condition, hasn’t had any damage that might have disturbed its alignment, and looks as though it’s well maintained.

“If we’re evaluating steer tires, we pay particular attention to the drive tires.”

Why is that?

“Because if something’s not right on the drives, it can affect wear on the steers. For example, if drive tires are out of alignment, that can cause serious irregular wear on the steers.

“We note anything unusual, then look at the evaluation tires.”

Important information is “chalked” onto the tread so it will be captured in photos. Later, the engineer can compare notes with photos to make sure data is correct.

What do you measure there?

This special gauge allows engineers to copy the tread contour and add it to their reports.

“We record the mileage and inflation pressure, the direction of rotation, make sure the tire is mounted in the position it’s supposed to be, and hasn’t been moved.

 “I clean as much of the tread as I can, then measure remaining tread depth in at least three locations in every groove, spacing them around the tire at roughly 90-degree intervals.

“Then I look at any irregular wear. We’ll measure the width, length, depth and how often the wear occurs. We mark irregular wear areas with chalk, so they show up more easily.”

Why do that?

“Because one of the things we do is take a photo of every tire. We send those in with our reports. Depending on the evaluation criteria, we might even measure crown radius or plot the tread contour.

“When I’m done, if it’s steer tires I’m looking at, the last thing I do before dropping the hood back down is take a final look at the tires and the vehicle, to see if there’s anything I missed.”

And what happens to all this information?

“I prepare a report, transferring my notes to the computer, and send it back to the engineering department. They collect reports like mine from several R&D engineers across the country.

“Our reports help the designers determine whether the tire is working the way it should, and help them determine any changes they might choose to make to create the next generation of prototypes.”

How many prototypes does it take?

“It varies. We’ve had tires that seemed to go almost directly from first prototype to market, and others that have required several revisions before they were ready.”

Does every tire company do this?

“It takes a very large company to do a good job of this kind of evaluation. It can easily take 15 months to two years to create and fully evaluate prototype tires, and much longer if prototypes have to be refined multiple times.

“It’s an extremely expensive process, but it’s the best way to get the very best tire performance.”

An R&D field engineer, like Loren Gwilliam, needs these to collect data that will be used to decide whether a new product is living up to expectations.