February 20, 2007 8:00 AM, EST

Editorial: The Clean-Truck Paradox

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For anyone who operates a commercial truck, there is little doubt about the importance of the vehicle’s fuel efficiency — especially in this era of historically high diesel and gasoline prices.If only the federal clean-air agency would keep that in mind when it prepares emission-controlling regulations.Irony begs closer attention by the regulators. As those attending American Trucking Associations’ Winter Leadership Meeting in Washington, D.C., were reminded last week, reducing diesel emissions has had an unconsidered consequence: Today’s cleaner trucks need to burn more fuel to travel the same distance as their predecessors.And burning fuel is the source of truck-generated air pollution in the first place.Actually, the diesel engines built with 2002 and 2007 emission-dampening technology are remarkably cleaner than many used to think was even possible. Smog-forming nitrogen-oxides and unburned matter that used to generate puffs of black smoke from exhaust stacks are being stripped to the lowest practical levels by advanced designs and ultra-low-sulfur fuel. Exhaust stacks now stay so clean that rust is becoming an issue, according to one truck manufacturer. But the technology has extracted a price, which must be paid by the truck buyer and operator. Not only is the new equipment more expensive, it is less fuel-efficient than the industry’s high marks.Truckers used to buy vehicles that got 10 miles per gallon. Today, with the addition of the clean-air technology, the average is more like 6 mpg, according to ATA officials.Perhaps this is the classic “two steps forward, one step back” syndrome. But does it have to be this way? ATA wants regulators to consider that question the next time they draw up emission-reduction targets. And there may well be a next time. Once 2010’s strict NOx limits are met by new engine-exhaust technology, the federal government is likely to turn its sights on the classic “greenhouse” gas, carbon dioxide — another byproduct of fuel combustion.A major forward step would be to have engines that burn less fuel.At the leadership meeting, ATA vowed to become more vocal about heavy-truck fuel efficiency.We ask clean-air regulators to vow to respect the fuel-efficiency paradox.This editorial appears in the Feb. 19 print edition of Transport Topics. Subscribe today.