No one's quite sure how recently proposed fuel efficiency standards will affect sticker prices of medium- and heavy-duty vehicles. Theoretically, getting more miles to the gallon should be a net-sum proposition.

Because reliability affects the overall cost-effectiveness of a fleet operation, the question is how well the environmentally friendly vehicles will work.

Last week, EPA and the Transportation Department provided details of the nation's first fuel efficiency standards for heavy-duty trucks. Similar to 1975's Corporate Average Fuel Economy (CAFE) fuel standards for cars, the "HD National Program" focuses on the second-largest contributor to the transportation sector's greenhouse gas emissions: large pickup trucks and vans; semitrucks; and truck and bus types including refuse, utility, dump, transit buses, shuttle buses, school buses, and emergency vehicles.

The proposed standards exclude sport utility vehicles, vans that hold 13 or fewer passengers, half-ton pickups, and trailers; and apply not just to the engine but the entire vehicle.

The program breaks vehicles into three regulatory categories, and proposes two types of standard metrics:

  • Tractor-trailers
  • Pickup trucks and vans: Target standard curves based on a "work factor" that combines payload, towing capabilities, and whether or not a vehicle has four-wheel drive.The standards would phase in from 2014 until 2018 (when there'd also be a separate standard to control air conditioning system leakage). Diesel emissions would be 17% lower and gasoline emissions 12% lower than 2010 levels.
  • Vocational vehicles, including tires: The standards would apply to three classes of chassis manufacturers: Light Heavy (Class 2b through 5), Medium Heavy (Class 6 and 7), and Heavy Heavy (Class 8), which is consistent with the engine classification.
  • Payload-dependent gram-per-mile (and gallon/100-mile) standards for pickups and vans.
  • Gram/ton-mile (and gallon/1,000 ton-mile) standards for vocational vehicles and combination tractors.
  • The agencies claim that, using technologies commercially available today, owners of most vehicles would recover their investment in technology upgrades within two years.

    "Most of us are playing wait-and-see," says Chris Amos, commissioner of equipment services for St. Louis and president of NAFA Fleet Management Association [], which asked Navistar Inc. Vice President/General Manager of New Business Ventures Dennis Huffmon to address the topic as part of his keynote address at next year's annual convention (Sun., April 10, 2011, 9:15 a.m., at the Charlotte Convention Center in North Carolina). "We may end up with higher-horsepower smaller engines that do the same amount of work as larger engines with the same horsepower.

    "With gasoline engines, you can add a turbo-charger like Ford's EcoBoost, which uses exhaust as a free energy source to increase horsepower with a smaller, more fuel-efficient engine.

    "But diesel engines are already fuel efficient. If I had to guess, I'd say manufacturers will downsize engine placement and increase blower size to increase horsepower.

    "The result will depend on the quality of materials. Turbo-chargers have been problematic because they overheat. I understand the new turbo-chargers are ceramic, which is expected to prevent metal fatigue. It remains to be seen if new and better materials reverse the trend."You fleet managers out there: what are your thoughts? Please share them with me at