+ Enlarge this image
Shifting Gears. Cat’s patent problems have not stopped product development, such as a new transmission venture.

By the time the year is through, the clean diesel movement will have made significant strides. Since 1996, when the U.S. Environmental Protection Agency began regulating off-road diesel tailpipe emissions, pollutants from many of the engines powering heavy construction machines have  been cut by more than 80%. By this time next year, over-the-road trucks will be more than 90% cleaner as well. Diesel fuel with an “ultra low sulfur” rating will be required on highway vehicles later this year, and the chrome exhaust stacks that flank the cabs of most trucks won’t be spewing clouds of black smoke into the air, thanks to new particulate filters.

And there is still more to come in the diesel clean-up campaign. The next decade will see even tighter restrictions on engine makers, fuel suppliers and equipment builders, which eventually will ripple down to construction firms. As costs increase, contractors will put more pressure on suppliers to make diesel engines more efficient and economical. Innovations needed to tackle the challenge will force engineers to reinvent the diesel engine and its subsystems.

Related Links:
  • As Biodiesel Becomes Popular, Users Weigh Its Benefits
  • Ergonomic Filters Could Make Mechanics� Lives Easier
  • It already is starting to happen, and equipment managers are watching closely. They expect to see “construction equipment hybrids, fuel cells and battery electric power” on the market soon, says Robert Andrade, vice president of equipment management for Parsons Corp., Pasadena, Calif. A board member of the Association of Equipment Management Professionals, Andrade predicts that traditional diesel fuel “will probably become too expensive” in the distant future and says that it is “a hazmat problem that continues to blossom.”

    As in the automotive sector, hybrid technology is the most likely candidate for alternative power on construction machines if manufacturers can hit the right marketing chords with fleet owners. Select models of pickup trucks and SUVs have gone hybrid and some commercial truck prototypes with hybrid engines are being tested in the field. The off-road market is bound to go that way, too. Hybrid engines featured on heavy construction machinery may be previewed “as early as this year,” says Darrin Drollinger, vice president of technical services for the Milwaukee-based Association of Equipment Manufacturers.

    Cleaner Fuel

    Clean air requires more complex engine technology. It also requires more complex fuel. With fuel economy on everyone’s mind, construction firms are becoming more savvy about how they manage fuel. More purchasing agents are scrutinizing the quality and power output of fuel as sulfur levels keep dropping. “We like to look at our fuel not only as price per gallon but also cost per BTU,” says Joe Fell, assistant equipment operations manager at Ryan Incorporated Central, Janesville, Wis. In June, refiners will reduce on-highway diesel from 500 parts per million to 15 ppm of sulfur.

    Helping refiners comply with the 15-ppm diesel standard has required an enormous effort from the engineering and construction community. “You don’t often have 100 to 150 refineries all having engineering people on the books at once,” says John Gieseman, director of refining for ABB Lummus Global, Bloomfield, N.J. “There’s still quite a bit of activity,” he says, pointing to the growth of refining in Asia as well as “a halo effect” from the push to ultra-low-sulfur diesel, as overall specifications for diesel fuel change worldwide.

    Most refineries have to add a “high-severity hydrotreater” to achieve compliance with the new fuel standard, says Jeffery Hazle, technical director for the National Petrochemical and Refiners Association, Washington, D.C. Virtually all refineries have added or retrofitted hydrotreaters.

    The estimated capital cost to bring the U.S. refinery industry into compliance with this year’s rule is $8 billion, which means the price of fuel is only going up. Production of ULSD has risen about 30% since a year ago, but it’s still a niche market at just 35,000 bbl per day. The growing pressure is evident in the price of on-highway diesel fuel. On Feb. 13, it averaged $2.48 per gallon, substantially higher than the price of $1.99 a year ago. EPA estimates that ULSD fuel will cost 4 to 7¢ more per gallon.

    Engine makers are doing all they can to improve fuel economy, but emission controls on engines eat fuel. Brian Etchells, a senior research manager for J.D. Power & Associates, like ENR a unit of the McGraw-Hill Cos., says average fuel economy for commercial trucks dropped last year below 6 mpg for the first time since the firm began polling truck users. The study, published late last year, focused on the 2003 model year, when diesel engine makers started adding exhaust-gas-recirculation valves, EGR coolers, variable-geometry turbochargers and other devices to cut emissions.    

    Trapped Soot. Particulate filters will replace mufflers on diesel trucks beginning next year. (Photo by Tudor Hampton for ENR)

    Trapping Soot

    Next year, truck makers will add diesel particulate filters that will effectively replace mufflers. The filters trap soot in the exhaust stream and catalyze it using exhaust heat and low doses of diesel fuel. The filters will need to be removed and cleaned every 18 to 24 months, says David McKenna, product manager for Mack Trucks Inc., Allentown, Pa. Users who want to do their own cleaning will need to buy a containment machine that costs about $7,500. “We think it will be just another tool,” McKenna says.

    As far as efficiency is concerned, Etchells says users will continue to experience maintenance and performance problems. But he has a more positive long-term outlook. Customer satisfaction drops significantly “any time new technology is introduced,” he says, but later improves “as they work out the bugs.”

    Test Set. With heavy R&D demands on engine makers, cost and quality are going up. (Photo courtesy of Deere & Co.)

    Engines made for off-road machines are in their third tier of EPA emission cuts and do not seem to be losing as much fuel as their highway counterparts, partly because engine designers are applying lessons learned from the on-highway diesel cleanup. “We’re actually seeing better performance, better fuel economy [and] improved efficiency in drive trains and components,” says Doug Laudick, project manager for Deere & Co., Moline, Ill. Deere’s engine designers say they are accomplishing 1% to 6% better fuel economy by making their clean diesel engines work more efficiently with other components on the machines.

    Maintenance remains a big issue for construction firms. Even though manufacturers have been able to increase horsepower ratings while stretching out oil-change intervals, potentially saving project operating costs, the engine oil requirements are changing constantly. Andrade says that “keeping the fuel lube trucks stocked with the right stuff at the right time on the right tier level” will continue to be a major training problem for contractors.

    Legal Battles

    Equipment vendors meanwhile are fighting to sell clean diesel technology to construction fleet managers while trying to bolster their market share through vertical integration and proprietary technology. The most high-profile fight is being...