Fleets Differ on Low-Rolling-Resistance Tires Ahead of Tighter GHG, Mileage Standards
This story appears in the June 5 print edition of Transport Topics.
As tightening federal greenhouse gas emission standards are pushing trucking toward low-rolling-resistance tires for trucks and trailers, several fleets are re- porting mixed results on the fuel efficiency, cost, durability and even safety of these tires.
The move toward LRR tires is the clear direction of the industry, said Tom Clauer, corporate manager of product planning for the commercial and over-the-road divisions at Yokohama Tire Corp.
All the manufacturers are going to shallower tread depths, he said. Tire tread depth is measured in 32nds of an inch.
Beyond regulatory pressures, shippers also are calling for greater efficiency from their carriers, Clauer said. “Customers are asking fleets, ‘Are you SmartWay-verified? Are you green?’ ”
The SmartWay program — a voluntary partnership between trucking and the U.S. Environmental Protection Agency aimed at reducing fuel consumption — will “probably take another drop in the rolling-resistance requirements,” he added. “So we’re kind of getting out ahead of that right now.”
Last year, EPA and the National Highway Traffic Safety Administration issued their final Phase 2 rule on GHG emissions for heavy- and medium-duty trucks. This will require the industry to make tractors and trailers more fuel-efficient through most of the next decade. The move represents the first time trailer makers will face federal mandates on aerodynamics and LRR tires.
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The first effective date for Phase 2 is Jan. 1, 2018, for trailers, followed by tighter rounds of truck and trailer standards in 2021, 2024 and 2027.
Less-than-truckload carrier Southeastern Freight Lines has been testing LRR tires from a variety of manufacturers on many of its tractors and trailers for about five years, said Steve Burdian, the company’s manager of tires and fleet service.
“We were testing before the mandate came out because, obviously, if somebody is touting fuel savings, you want to get on top of that,” he said.
The biggest downside to LRR tires is that they wear out so much faster, “so your cost per-32nd is just not there,” Burdian said. “And, honestly, from a replacement standpoint, when those wear out, we’re going to end up putting more tires on the equipment over [its lifespan].”
For Southeastern, the challenge is weighing the cost of replacement versus the fuel savings, Burdian said.
However, anything less than 5% in fuel savings is difficult to measure, he said, because of the many variables that can affect fuel economy, such as wind and temperature. “We believe [LRR tires] are more fuel-efficient, but we can’t measure it.”
The tire manufacturers are working on better rubber compounds that will make them last longer, “but right now, they don’t have that,” Burdian said.
In its LTL operations, many of the fleet’s trailers end up in city delivery with a lot of twisting and turning, he said. “We obviously see increased wear.”
From a fleet standpoint, the fuel savings probably won’t outweigh the cost of tires, Burdian said.
One tactic that does generate a measurable increase in fuel economy is the installation of trailer side skirts. “From a trailer standpoint, we can see and measure fuel savings with skirts,” Burdian said.
Based in Lexington, S.C., SEFL ranks No. 28 on the Transport Topics Top 100 list of the largest for-hire carriers in the United States and Canada.
Another fleet executive expressed concerns about the safety of LRR tires.
Gary Percy, president of A.D. Transport Express Inc. in Canton, Mich., said he decided to replace every drive tire in his fleet of 600 tractors after drivers reported five jackknife incidents on wet pavement in a matter of months after installing LRR tires. The company also has 1,400 trailers.
At first, he assumed it was driver error that caused the problem, but after viewing an in-cab video of one of his drivers losing control, he’s convinced that the tires were to blame.
“I’m 100% sure that these tires are the cause of major problems on wet roads,” Percy told Transport Topics. “Before, we had jackknife incidents only during icy or white-out [snow] conditions.”
Since making the switch to another type of tire made in Canada that is designed with slightly higher rolling resistance, Percy said he has had no complaints or jackknife incidents with the same drivers on the same roads and with same tractors that are speed-governed at 68 mph.
It is not clear how widespread this problem is.
“We’ve not heard of issues such as these,” said Mike Roeth, executive director of the North American Council for Freight Efficiency, an organization that tests the performance of components, including tires, that claim to offer fuel savings.
A spokesman for the Technology & Maintenance Council of American Trucking Associations also said it has received no complaints about the loss of traction on LRR tires.
Percy said he stands by his decision to change out a total of 2,800 tires at a cost of more than $750,000. Although none of the jackknife incidents resulted in death or major injuries, Percy said the cost for each incident was at least $150,000 with the most serious being $500,000.
Southeastern’s Burdian said he has no concerns with the traction of LRR tires. “We see our tire costs increasing — that’s just the bottom line,” he said.
Yokohama’s Clauer said there are “no worries, at least from my company’s standpoint, about safety. We have proven that many, many times.”
Original equipment manufacturers put their trucks through quite extensive testing, he said. Shallower tires “with less 32nds have actually have been proven to have more traction than deep 32nds,” he said. “So technology and chemistry applied to these products are creating more traction.”
Mike Eggleton Sr., president of Raider Express, a Texas-based refrigerated, over-the-road truckload fleet with 250 tractors and 500 trailers, also said he has no safety concerns. “There is no safety degradation with a low-rolling-resistance tire.”
LRR tires have been on all the company’s tractors and trailers for the past 10 years, Eggleton said. The company uses a mix of Michelins and Bridgestones.
Based on fuel economy data collected by its telematics system, Raider Express has found that LRR tires save about half a mile per gallon versus standard tires, he said. “We constantly look at our spec to determine what is the best for fuel efficiency and fuel economy.”
Eggleton said if a fleet is measuring its tire cost per 32nd of an inch of tread depth, for example, it might have slightly higher costs per mile. However, “I see a very, very small difference in the cost per 32nd or the cost per mile,” Eggleton said. “It’s negligible.”
Previously, fleets just wanted tires with traction, decent mileage and durability, Yokohama’s Clauer said.
“Our challenge is to accomplish all of those things and still reduce the rolling resistance,” he said, noting this can be done by advancing the technology, compounding chemistry and tread design.
