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RV Tire Safety: Is better tire wear AND better fuel economy possible?

By Roger Marble
We all see posts from people wanting better tire wear and better fuel economy. Here is some information from a friend, “Dr. Joe”:

Wear, traction and rolling resistance are interrelated (but adjustable) factors determined mostly by tread material properties fixed during the design stage of tire development. The rubber chemist’s enduring dilemma has been that enhancing one tread attribute influences the other two – usually adversely. Marketing professionals tend to use the term “balance” rather than “tradeoffs” to describe these conflicting variables.

Based on my reading of recent industry press releases, tire wear and traction seem to be playing “second fiddle” to rolling resistance in today’s push for “greener” tires – even though fuel efficiency has not been a top priority for U.S. consumers. It is, however, well known that good tread wear resistance is important to motorists purchasing replacement tires.

Contrarily, because of CAFE (Corporate Average Fuel Economy) mandates, OEMs (Original Equipment Manufacturers) consider tread life subordinate to rolling friction in their procurement of new car tires. Unarguably, any decrease in wear-out mileage increases the frequency of tire replacement and unwelcome scrap generation.

Tire traction, nonetheless, is important to safety conscious motorists; it is constrained by road conditions which control traction limits encountered by given tread compounds and patterns. These can be optimized for wet, dry or snow performance. While over 80% of tires in service in the U.S. are rated at the UTQG (Uniform Tire Quality Grading) traction level “A”, only 15% are rated at the highest level “AA”. Surprisingly, no real-world data exists indicating that tires with higher rated traction grades are less involved in highway accidents than lower rated ones – with snow tires an exception as they are not UTQG rated.

For improved all-weather traction, so-called “rain tires” have been touted on-and-off over the decades, and promoted extensively by U.S. Rubber (now Uniroyal) beginning in 1965. Wet grip was achieved, then and now, by sacrificing tread wear. While this is an acceptable trade-off in Europe, U.S. consumers have consistently rated long tire life more important than tire grip; and with relatively cheap fuel, rolling resistance tends to be a non-issue for individual tire buyers. The most common reasons reported by the influential Consumer Reports (2019) for selecting a particular replacement tire brand are price (44%), tread life (40%) and brand trust (31%). Similarly, the respected J. D. Power new car owner survey (2021) rates the top three tire satisfaction metrics as wear, ride and traction (in order of importance).

Regarding tread life, surveys of large numbers of scrapped consumer tires usually show that the majority are three to four years old when replaced. Since Americans drive between 11,000-12,000 miles per year on average (according to Federal Highway Administration), this means that most passenger car tire wearout mileages occur between 33,000-48,000 miles. If light vehicle tire lifespans could be increased an additional year, demand for new tires would be reduced with lessened environmental impact.

Also, tires become more fuel efficient as they wear. I wonder what an environmental and economic cost-benefit analysis of tire life extension might yield? Mainly due to existing and proposed government mandates, U.S. consumers have been, or will be, forced to unwittingly accept reductions in tire life with increased costs in concert with lower rolling resistance. Then we encounter further demands placed on EV (Electric Vehicle) tires – which need improvements in tread wear, traction, and rolling resistance compared to their ICE (Internal Combustion Engine) powered counterparts.

Additionally, the California Energy Commission once again announced plans to implement a program to ensure that replacement tires sold in that state are as energy efficient as OE (Original Equipment) tires. This will only exacerbate the confounding situation facing consumers valuing tire life.

Ponder Michelin’s transitional development of the radial tire after WWII. Wearout mileages were doubled while rolling friction was reduced by 25% compared to existing cross-ply tires. Could the industry now develop tread compounds and/or tire constructions that at least make desirable improvements in both wear and rolling resistance without comprising grip?

Unexpectedly, Bridgestone, Arlanxeo and Solvay have just announced material technology that claims to achieve just that; up to 30 percent better wear efficiency and six percent reductions in rolling friction. Hopefully, this technology will be licensed to others if the claims are justified.

*****

Joe Walter enjoys teaching Vehicle Dynamics and subjects related to tire materials and mechanics at The University of Akron. He previously served as Vice President and Director of Bridgestone Americas Research Center in Akron and President of its European Technical Center in Rome. Joe obtained graduate and undergraduate degrees in engineering from Virginia Tech a long time ago.

While Dr. Joe’s article is aimed at the passenger and light truck vehicle market, you can be assured that as new technologies are developed in one sector of tire design the features and advantages soon spread to other product lines.

Have a tire question? Sign up for Roger Marble’s new Facebook Group: RV tire news, information and discussion, hosted by RVtravel.com and moderated by Roger. He’ll be happy to help you.

Read more from Roger Marble on his blog at RVtiresafety.net or on RVtravel.com.

 ##RVT1010

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Richard Davidson
2 months ago

Just wish there was a chart of some type that would list the best (rated) tires.

TIM MCRAE
2 months ago

In the late 2000’s Michelin & Ford collaborated on fuel efficient and long life tires on several vehicles. (i had several 2009 Ford Escapes). I was so impressed with these tires that I have owned four sets.

If I remember they were Latitude Tour model. I got well over 100k miles out of each set. I think they were rated for 90k & I got close to 110k on some of the sets.

I buy passenger tires now based solely on the best speed / duty rating and highest warranty mileage I can get.

Drew
2 months ago

Does the Calif. measure mean we won’t see those monster trucks with huge knobbys on them? Maybe they’ll be forced to go out of state to get those tires.:)

Crowman
2 months ago

Very interesting.

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