While there weren't many big new product announcements at this year's Mid-America Trucking Show last week in Louisville, Ky., there was one theme that rang loud and clear through nearly every product introduction and enhancement announced: improved fuel economy, and as part of that, lighter weight.

A number of truck and engine OEs said the focus is shifting from the battle over which technology is better to meet EPA's 2010 NOx and particulate emissions limits, to an emphasis on fuel economy.

"The past decade was clearly about who could meet emissions best, and I think we did that," said Rich Freeland, Cummins vice president and president-engine business. "The winner of the next decade will be about who delivers fuel economy best."

Cummins said real-world data has confirmed that its EPA-2010 spec ISX15 engine delivers 6 percent fuel economy improvement over its 2009 product. Some customers could see even better results thanks to "significant calibration improvements" Cummins has identified that were launched early this year, said Steve Charleton, Cummins vice president and chief technical officer-engine business.

Ustian: Not a Question of If We're Going to Get There

Addressing members of the Heavy Duty Manufacturers Association during HDMA's annual breakfast and breifing, Navistar President and CEO Dan Ustian noted that in the 1980s, most heavy-duty trucks got 4 to 4.5 mpg. Today, it's around 6.5 to 7 mpg. That's been done without a government mandate, he noted.

Nevertheless, he said, the government has decided to propose fuel efficiency rules for trucks, an effort under way at the Environmental Protection Agency (which regulates engines) and the National Highway Traffic Safety Administration (which regulates vehicles.)

"You don't need that in trucking," he said. "Our customers are demanding it. We're all going to do it, we have to if we're going to stay in business." The challenge for OEs, he said, will be the paperwork and documentation required to prove compliance. "It's not a question of if we're going to get there, it's the paperwork."

As the industry moves forward with improved fuel efficiency, Ustian said integration would be a key strategy. Transmissions, drivetrain, cooling, powertrain, fuel air management, brakes, axles -- all must work closely together.

He also noted that when you look at what affects fuel economy for a truck going 65 mph, the powertrain is only 18 percent. Fifty percent is aerodynamics, while 32 percent is rolling resistance.

"You need an engine designed for your body," Ustian said. "We're able to get better air flow by being able to move our engine back 8 inches because it's designed for that truck."

He also said the truck makers need to work with trailer makers to figure out how to reduce the fuel wasted by air getting caught between the tractor and trailer.

Ustian also stressed that weight will be important. "You'll hear everyone talk about weight," Ustian said. "For a thousand pounds it's about 2.5 percent efficiency. Everyone's looking at frame rails axles, fifth wheel, suspensions, trailer, tires/wheels."

Bendix: More Than Trucks and Engines

At a Bendix press event, Mark McCollough, director of air treatment, said we can expect a 3 percent to 15 percent reduction in fuel use for tractors by 2014 under the EPA/NHTSA proposed rules.

Bendix believes the regulation should include a credit system, much as is used by the EPA for emissions regulations. "EPA and NHTSA will create a list of technologies where if you use these, you can get credits to apply to other engines or vehicles," he said, citing as examples tire pressure monitoring, Bendix's PBS air system, clutched air compressors, and air disc brakes to reduce weight.

Bendix has completed some North American closed-track vehicle tests of its new air management system, using a standard SAE fuel economy testing protocol, which was representative of the cycle of a beverage hauler. The resulting fuel economy savings were 4.6 percent using the Bendix PBS Air Injection Booster, Bendix Turbo-Clutch Air Compressor, and Bendix Electronic Air Control Dryer.

Mack, Volvo: Combination Approach

Mack had people talking with its claim that it's possible to achieve fuel savings of 12.5 percent with a combination of its refined roof and chassis fairings, additional Econodyne ratings for its Mack Power engines, and Mack's automated mechanical transmission.

Customers ordering Pinnacle model sleepers with the improved aerodynamics can expect up to a 6 percent fuel efficiency improvement, said Jerry Warmkessel, Mack's highway marketing manager.

Four new Econodyne ratings are the MP7-405E, MP8-415E, MP8-445E, MP8-505E. Through an enhanced fuel mapping strategy, Mack's EconoBoost intelligent torque management system offers an extra 200 pounds-feet of torque if drivers stay in upper gears and let the engines lug to low rpm.

"We found that drivers can significantly increase fuel efficiency by remaining in the top gear as much as possible," said David McKenna, director of powertrain sales and marketing. "EconoBoost initiates at 1,300 rpm, providing additional power that allows drivers to remain longer in the top two gears. The engine torque reverts back to the lower profile when the engine senses situations with zero torque input, such as cresting a hill."

Compared to current specifications, it's possible to achieve fuel savings of 12.5 percent by using a new roof fairings and side skirts, choosing one of the new Econodyne engine ratings, and spec'ing Mack's mDrive automated mechanical transmission, said David McKenna, director of powertrain sales and marketing.

Sister company Volvo Trucks North America also stressed how a combination of specs can make today's trucks much more fuel efficient than the 2007-EPA-spec models, noting that aerodynamics, automated mechanical transmissions, and more fuel-efficient engines are becoming more critical to customers.

VTNA announced a new engine software packaged called "mass based variable torque" designed to adjust the engine's torque when the truck is lightly loaded to improve overall fuel efficiency. In addition, new exterior components offered for VTNA's "fuel enhancement" package for 2011 Volvo VN highway tractors include redesigned mirror heads with aerodynamic shrouds and arms, redesigned hood mirrors, new bumper and side fairings, and a newly designed bug deflector which further improves fuel efficiency.

Altogether, VTNA believes its fuel efficiency offerings can boost fuel economy by as much as 8 percent for its 2011 trucks when compared to 2007 models.

More Announcements

Roadranger emphasized "light and strong," with the introduction of Spicer one-piece aluminum driveshafts, which are up to 100 pounds lighter than a traditional two-piece steel product -- 40 percent less, with comparable or greater performance.

Similarly, the new Spicer Pro-40 40,000-pound tandem was designed to take additional weight out of the product for key markets in high-volume linehaul, regional haul and city delivery applications. It's 100 pounds lighter than the Dana DS404 (which will still be available for applications where it's needed), and 120 pounds lighter than the nearest competitor, Dana said.

At Peterbilt, officials announced that customers spec'ing new equipment can take advantage of two speed control management options that can be specified independently or jointly based on customer needs. Progressive Shift Control encourages drivers to shift at reduced engine speeds while in lower gears, and Gear Down Protection encourages drivers to shift into higher gears sooner in order to use the engine at a lower engine speed when the vehicle is at higher road speeds.

Allison Transmission showed off what it calls a "radically new transmission design" for tractors that split their work cycle between city and highway conditions. Although it's at