The Singles Scene
The fuel efficiency of singles has long been touted, and is now being tested.
Mark Putz
Associate Editor
When it comes to innovations in truck tires, fleets often accept change at a glacial pace. Resistance to wide-based single tires is understandable. Doubles are dependable. But savvy fleets will always give new technology a try — especially if it promises better fuel economy and increased payload.
Wide-based singles have long been labeled as a limited application tire, best for running close to home. But they're beginning to gain grudging acceptance by some over-the-road fleets.
With rolling diameters matched to the popular low-profile dual tire size, and a growing choice of drive and trail positions, more and more fleets are exploring the concept of wide low profiles.
Michelin's X-One line of low profiles has enjoyed increasing popularity, branching out from tanker and other traditional singles applications to line-haul fleets. The first fleets to try the X-One wanted to haul more freight per trailer, a concept made more urgent by the new hours of service rules. Carriers like Loyal Limited in Peoria, Ariz., claim to be able
to add up to 1,000 additional pounds of payload with the X-One. The additional revenue has translated to roughly $30 per payload, per day, while lowering operating costs with a half-mile per gallon increase in fuel efficiency.
The fuel efficiency of singles has long been touted, and it is now being tested. Eddie Luper, director of maintenance for Arlo G. Lott Trucking, Meridian, Idaho, said his trucks logged improved fuel economy. "The fuel savings were very noticeable from the beginning. We tested the X-Ones versus duals on sister trucks and same hauls with 106,000 GBW rating; hauling in the intermountain West and Canada. The X-Ones delivered an average of 5.5 miles per gallon versus the duals at 4.9 mpg."
Similar fuel savings were also seen by Ronnie Holland, vice president of risk management, Star Transportation Inc. Nashville, Tenn. "We did see a savings with the X-Ones over the duals."
Michelin reports that since its introduction of the X-One three years ago, fleets have reported significant weight savings — some reducing overall weight from 800 lbs. to 1,300 lbs. when used in both drive and trailer positions. R&N Trucking Inc., Mesa, Ariz., reported savings of 800 pounds on tractors switching from 11R22.5 tires in dual to 445/50R22.5 X-One XDA H/T drives, and an additional 800 pounds on the trailer positions.
More Choices
Goodyear started production two years ago on its first wide-base tire, now undergoing fleet testing. Goodyear will be rolling out two new low-profile singles — the G3SSD drive tire and G3SST trailer tire — sometime this year. Feedback, so far, is mixed. Drivers love the ride and the stability of wide-based tires. But some maintenance managers are skeptical, citing the old question of emergency over-the-road availability and greater stress on the wheel assemblies.
Goodyear is telling customers to look at what's right for their operation. For some fleets, it may come down to weight savings and fuel economy, particularly with the penalty incurred by 2002 engines. Fleets looking for more ways to cut fuel costs might go with low-profile tires because they weigh less and there is less rolling resistance.
Al Cohn, manager of strategic initiatives at Goodyear, says, "Aside from mileage per tire, there are questions about retreading. Most fleets expect two retreads out of a tire. They may only get one retread from a widebased tire." And a fleet must review its maintenance schedule to see if it is up to snuff on maintaining tire pressure, since running any tire underinflated guarantees extreme heating.
As the number of manufacturers introducing new wide-based singles grows, more fleets will be giving them a try. Bridgestone says it is building up a supply of its Greatec line and will be announcing fleet reactions in the first quarter of 2004.
Continental is testing a product with several fleet partners and expects to roll out a tire this year.
Only time will tell if the touted benefits — rig stability, lower wheel costs, and increased fuel efficiency — can melt long-hauler resistance to wide singles.
