Walkin’ the walk

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Goodyear just introduced new over-the-road steer, drive and trailer tires that it says are more fuel-efficient than its current Unisteel products, and I’ll get to them in a minute.

What impressed me most about the tire rollout was Goodyear’s invitation to the press to come to its proving grounds in San Angelo, Texas, to observe an SAE/TMC Type II fuel consumption test, pitting its existing tires against the new tires equipped with what it calls Fuel Max technology.

You might be tired of hearing me say this, but the Type II test has emerged as the most accurate way to compare fuel economy, as it removes as many variables as possible, such as weather, road surface and vehicle condition, while lending itself to consistency and repeatability. It goes something like this:

In this case, two identical tractor-trailers – a control rig and a test rig with the same powertrain, mileage, horsepower, GCW, tires, pressure, etc. – are fitted with removable, portable fuel tanks, which are weighed before and after identical runs of at least 28 miles at the exact same highway speed. Fuel consumption is measured by tank weight, and the two rigs are compared as a baseline. Three runs, which must produce results within 2 percent of each other, are made. In this case, the two rigs’ fuel consumption figures were consistently within 1 percent of each other.

Next, the test is repeated, with the control rig unchanged, and the test truck fitted with the component to be tested – in this case, the new tires. Over the course of three runs, with results within 2 percent of each other, the test truck had consumed about 7.5 percent less fuel per run.

OK, about the tires. At the heart of Fuel Max, says Goodyear, are new, proprietary tread compounds that run cooler. Makes sense, since any heat a tire makes is energy going off to the atmosphere that could be spent making miles. Tires featuring Fuel Max technology include the Unisteel G395 LHS steer tire, Unisteel G305 LHD drive tire and Unisteel G316 LHT trailer tire in standard (11R22.5) and low-profile (295/75R22.5 and 285/75R24.5) sizes. Goodyear also is offering UniCircle and precure retreading with Fuel Max technology.

While the company acknowledges that Type II test results are obtained under ideal circumstances and probably are optimistic for real-world applications, it says a 4-percent mpg improvement should be realistic in everyday driving – especially since nearly 8 percent has been verified as possible.

Now, I don’t mean to suggest that other manufacturers don’t use Type II testing to verify their products. OEMs and major suppliers do it routinely, and fleet operators are encouraged to examine the results before making purchasing decisions. And that’s particularly advisable in the case of lesser-known purveyors of additives and devices claimed to improve fuel economy. Why shouldn’t such products be held to the same industry-recognized standard as tires?

It’s all about credibility – and it beats the hell out of talking the talk.