DETROIT—The auto industry is putting improved tires onto cars these days, but consumers aren't so sure they like the results.
It is a rare disconnect between industry ingenuity and consumer stubbornness—and neither the auto makers nor their tire suppliers can do much to correct it at the moment.
Blame it on CAFE.
Car companies have been pushing tire makers for decades to create more fuel-efficient tires that generate less energy-eating road friction. And now that the auto industry is under federal mandate to meet significantly stiffer corporate average fuel economy requirements, tire makers are delivering exactly what car companies want.
But the resulting "low-rolling-resistance" tires that are now proliferating on new models from Ford, Nissan, BMW, Subaru, Kia and other companies can leave drivers unimpressed. Critics say the more fuel-efficient tires can lack road grip—something even their manufacturers concede. And some customers are underwhelmed by the very thing that the tires are promising—better fuel economy results.
Reviewing the newly released Kia Soul EV in November on Green Car Reports, auto writer Bengt Halvorson praised the car—but added, "The only thing it doesn't have is much grip; in the tightest hairpin corners you'll notice that the low-rolling-resistance tires simply won't let you enjoy that to its fullest."
The secret sauce for the tire concept is a reduced contact area with the road. Tire makers are doing that through new tread patterns and harder sidewalls. But reduced road contact has implications for braking on a wet road or taking off at a green light—especially compared to the wide, performance tires of the recent past.
Fuel economy vs. handling
The dilemma is this:
• Auto manufacturers need every scrap of fuel economy gain they can gather to meet the EPA mandate of a 54.5 mpg fleet average by 2025.
• Low-rolling-resistance tires potentially can add a mile or two to a vehicle's fuel economy numbers. And as a result, new-vehicle programs in all segments are pressing tire suppliers to prioritize low-rolling resistance, says Steve Rohweder, Goodyear Tire & Rubber Co. technology director for North America.
• But tires tend to provide less in road-handling performance and wear out sooner. So when it comes time to replace them, the consumer is less likely to ask for them a second time, reports Brent Gruber, global automotive division director at J.D. Power and Associates.
• And because tire makers sense that low-rolling resistance is not going to be popular in the replacement market—even though there is no real price premium over ordinary tires—they are less than enthusiastic about pushing the technology.
"We don't believe the consumer will embrace that," says Joe Maher, passenger and winter tire product manager at Continental Tire. "We want to be competitive in rolling resistance. But we don't care to lead in that area in the replacement market. We think wet traction is a more important attribute for the Continental brand."
Maher illustrates a sticky scenario that has become common in the tire business: A customer with worn-out tires drives to a retailer to buy a new set. The dealer appeals to the customer's interest in improving fuel economy and recommends a set of low-rolling-resistance tires. The customer has them installed and drives away—noticing on the car's fuel economy monitor an immediately worsening performance.
Because a set of older tires with worn-down treads has the lowest “rolling resistance” of its product life, Maher explains. New tires—even brand-new low-rolling-resistance tires—have their full treads and generate more road friction than the worn-out tires. Low-rolling-resistance tires indeed deliver better fuel economy performance, but over the life of the tires.
That creates the potential for an unhappy customer, Maher says. “And that creates a problem for the retailer. So they're a little bit reluctant to sell low-rolling-resistance."
None of which lets the auto industry off the hook.
IHS Automotive forecasts that original-equipment fitments of low-rolling-resistance tires increased to 25 percent of all models this year from 21 percent last year. In 2019, they will be on 30 percent of all new vehicles, and in 2020, on half, forecasts Bruce Harrison, IHS managing director.
And that forecast doesn't change in light of the recent plummet in prices at the gas pump, he adds. The shock of rising gas prices in 2007 and 2008 may have triggered the industry's commitment to more fuel-efficient cars and trucks, but prices falling below $3 a gallon do not erase the resulting CAFE rules.
“Auto makers are clearly clamoring for these tires as a tool for better fuel results,” Harrison says. “But that doesn't really translate to the retail world. The general population is more interested in other tire characteristics—like price and tread life.”
Nissan wants to have low-rolling-resistance tires on all of its models in the coming years as they are redesigned and re-engineered for better fuel economy. This month, Nissan will introduce the new-generation 2015 Murano crossover, a vehicle intended to represent the brand as a prestige vehicle and woo marginal luxury buyers out of Lexus and BMW vehicles. Murano marketing materials list low-rolling-resistance tires among the crossover's technology enhancements.
“Low-rolling resistance is spreading to different segments,” says Steve Monk, Nissan North America's chief vehicle assessment specialist, who makes sure new Nissans achieve their performance targets.
“The typical trade-off is usually with grip. If your tire is very low-rolling resistance, it's freer to roll in steering and braking. But those requirements aren't relieved just because we're trying to get to better fuel economy. That's the challenge we create for ourselves.”
The consensus in the industry is that the tires will either get better and consumers will become more accepting of them, or alternatives will arise to solve the problem.
The tires introduced on Kia's new electric Soul are being marketed as “super-low-rolling-resistance” tires.
Steve Kosowski, manager for long-range strategy at Kia Motors America, says the tires are a step beyond what other auto makers have been introducing in the past couple of years. Manufactured by Nexen, the new "supers" reduce enough friction to contribute 3 to 5 miles of extra driving range for the battery-powered car. The Soul boasts a battery range of 93 miles, positioning it above the EV-segment leader Nissan Leaf, which claims an 84-mile range.
Kosowski says the new Kia tires achieved a 10 percent improvement in rolling resistance from the existing generation of products. The Nexen tires incorporated a higher-density inner liner and a stiffer sidewall design.
Tread design and material hardness are two of the biggest pieces of low-rolling-resistance technology. Rubber tires, by their nature, deform as they roll across the pavement, generating heat and consuming energy. Tire engineers like to point out that the ideal example of low resistance rolling is a steel train wheel on a steel track—but that is hardly something a consumer would find attractive on an automobile.
Kurt Berger, consumer sales engineering manager at Bridgestone, believes the science of low-rolling resistance is steadily improving.
“What defines that tire, versus a conventional tire, is a moving target—and a fairly rapidly moving one," Berger says. "A low-rolling-resistance tire of 2010 would not be considered a low-rolling-resistance tire today. We've really been pushed in a short time to reducing rolling resistance further."
Bridgestone has begun supplying BMW's new i-series electric and plug-in hybrid vehicles with a more fuel-efficient tire technology it markets as “ologic.”
Consumer Reports, one of the leading influencers of market attitudes, has been tracking low-rolling-resistance tire values and also monitoring consumer interest levels. In 2010, the organization surveyed car owners to ask what sort of direct gain they would expect to see in fuel economy in return for switching to low-rolling-resistance technology.
“The answer we got was they expected a 5 to 10 mpg improvement,” says Gene Petersen, Consumer Reports tire program manager. “Clearly, they have no idea how it works. Our tests indicate that for a 10 percent reduction in rolling resistance, you'll get a 1 percent gain in fuel economy."
The issue continues to roil.
Five years ago, the National Highway Traffic Safety Administration proposed introducing a national standard to gauge low-rolling resistance, to be used as a consistent consumer guide, similar to EPA fuel economy ratings. That standard has not been completed.
California regulators also have proposed creating a low-rolling-resistance guide, but that plan has stalled. And California proposed requiring commercial trucks in the state to use low-rolling-resistance tires. That idea also stalled, and regulators never resolved the question of what truck drivers would do upon crossing the state line from outside California.
J.D. Power's Gruber is interested in learning whether consumers might be slowly warming to the technology as more new vehicles tout the tires.
Last year, Power published the results of an owner-satisfaction survey that found "many consumers are concerned that equipping low-rolling-resistance tires on their vehicle means compromising traction and durability in exchange for better gas mileage."
Power plans to repeat the survey again in 2015 to see whether attitudes have improved and publish the results next spring.
“I think the industry is realizing that it hasn't done a particularly good job of messaging what these tires are all about,” Gruber says. “That will change as the tires become