Chasing 10 mpg

by James Menzies

WASHINGTON, D.C. – Freightliner has introduced a new version of its flagship Cascadia, which it claims will be 5% more fuel-efficient than today’s version, even with all the latest aerodynamic fairings.

That makes it 7% more economical than the majority of Cascadias on the road today and 5.5% more fuel-efficient than its closest competitor, the company announced.

The 2014 Cascadia Evolution has achieved an impressive 10.67 mpg on closed circuit testing pulling an aerodynamic trailer and 9.31 mpg in over-the-road testing, the company announced during a recent unveiling.

Aerodynamic improvements were achieved through subtle front-end enhancements – so subtle in fact, the company didn’t bother covering the front end during cross-country on-road testing, as the Evolution looks very similar to today’s Cascadia. Exterior changes include: a new air dam, bumper closure, a redesigned windshield seal and a hood-to-bumper fill. Other enhancements include an improved cooling system, more aerodynamic mirrors and antennas that are integrated into the cab.

Daimler also improved upon its Detroit DD15 engine for further fuel economy gains, shedding 100 lbs and incorporating a new asymmetric turbocharger along with a new amplified common rail fuel system. Officials say the new turbo is less complex than variable geometry turbochargers and was designed specifically to work with Detroit’s DD15 EGR system.

“We examined every detail to ensure that no stone was left unturned when developing the Cascadia Evolution,” said TJ Reed, director of product marketing for Freightliner Trucks. “The result is a truck that will immediately benefit fuel economy performance and overall cost of ownership.”

Freightliner has assembled an ultra-fuel efficient spec’ that includes: wide base tires, wheel covers and the new Detroit automated transmission in a 6×2 configuration, and it was this truck that yielded the greatest fuel savings. However, when the truck becomes available in 2013, customers will still have the option of spec’ing Cummins engines, Eaton transmissions and Meritor axles if they so choose.

“But the most fuel efficient combination will always be the captive one,” said Daimler Trucks North America president and CEO Martin Daum, speaking of the combination of a Detroit engine, axles and transmission.

The Cascadia Evolution with integrated powertrain will consistently deliver a 7% fuel savings over most Cascadias on the road today, Daum said.

Mark Lampert, senior vice-president of sales and marketing, said pricing of the new model has not been finalized and while it will be priced higher than today’s Cascadia, he said the fuel savings will provide a return in short order.

“I think what we will see is the value proposition and corresponding payback for customers who choose to go with the Evolution will be quite short,” Lampert said. “It will be within a year to a year-and-a-half timeframe; the payback will be much shorter than anybody’s trade cycle.”

David Hames, general manager of marketing and strategy with Daimler, shared fuel economy test results that showed today’s Freightliner Cascadia with DD15 engine is the most fuel-efficient Class 8 vehicle available, but he admitted competitors were closing the gap with recent enhancements.

“The Cascadia with its 2011 aerodynamic improvements was still the best-in-class vehicle in terms of fuel efficiency, but the gap was beginning to narrow and we weren’t waiting for the competition to catch us,” Hames said.

Freightliner will be delivering customer demonstration units of the Cascadia Evolution later this year with production set to begin in early 2013.

Putting it to the test
Freightliner knew changes to its Cascadia model would provide fuel savings, but just how significant those savings would be needed to be determined through some extensive testing.

With that in mind, the company set out on its Evolution of Efficiency Tour, which pitted the new Cascadia Evolution against a “baseline” Cascadia in “first generation” EPA2010 trim.

“The Evolution of Efficiency Tour provided us with the unique opportunity to gauge the fuel efficiency of our newest truck – the Cascadia Evolution – against the Cascadia, our most fuel-efficient product to date,” explained Freightliner’s Reed. “This tour put our latest technologies and innovations to the test in real-world circumstances, and validates our continuous achievements in fuel economy over the past several years.”

The tour covered 2,400 miles between San Diego, Cal. and Gastonia, N.C. from May 17-23. The Cascadia Evolution featured a 125-inch tractor with 72-inch raised roof sleeper, the redesigned Detroit DD15 engine, Detroit tandem rear axles and an Eaton UltraShift Plus transmission. The baseline truck was a similarly spec’d Cascadia featuring only the first generation aerodynamic package.

The cross-country route covered various terrain and drivers averaged between 250 and 425 miles per day, running at a cruise speed of 62 mph grossing 76,000 lbs. Fuel usage was measured by Automotive Testing and Development Services, using high-accuracy fuel flow meters, Freightliner officials explained.

Drivers and trailers were swapped at the midway point of each day to account for driver- and trailer-related variables.

“It was imperative that we followed very precise testing procedures to ensure the integrity and accuracy of the test,” said Al Pearson, chief engineer, product validation engineering for Daimler Trucks North America. “In comparing the vehicles, we followed a standard fuel economy test procedure as close as possible given the unique nature of this drive. Very few fuel economy tests encompass these kinds of mileages and terrain so we went to great lengths to ensure that the vehicles were operated as similarly as possible and in accordance with standardized test procedures.”

In the end, the Cascadia Evolution consumed 7% less fuel than its predecessor.

On the track
Freightliner also tested a Cascadia Evolution that was optimally spec’d for maximum fuel savings and achieved a staggering 10.67 mpg on a closed circuit.

The test was conducted prior to the Evolution of Efficiency Tour, at the Continental Proving Grounds in Uvalde, Texas.

A Cascadia Evolution, powered by the redesigned Detroit DD15 engine, was equipped with the new Detroit DT12 automated transmission, wide-base tires, in a 6×2 drivetrain configuration and pulled a specially-designed trailer fitted with numerous aftermarket fuel-saving technologies currently available. (It was expected the truck itself would get about 7.64 mpg pulling a conventional van trailer without the aerodynamic add-ons. This compares to a baseline of 7 mpg achieved by today’s Cascadia).

The truck was run over the 8.5-mile track for 1,000 miles at an average speed of 60 mph with a gross weight of 76,000 lbs, company officials said.

“The closed-track demonstration enabled us to eliminate interfering elements of a typical on-highway fuel economy test such as traffic, construction and speed variations,” said Pearson. “The use of a closed test track allows us to demonstrate pure fuel economy potential with ambient weather conditions being the only uncontrollable factor.”

Had it not been for some rain, which caused the tires to lose some grip, officials said it’s possible the Cascadia Evolution may even have reached 11 mpg.

The test results were especially gratifying for DTNA’s Daum, who in one of his first speeches as CEO in 2009 predicted there will be a 10 mpg truck on the market within the span of his career.

While on-road testing showed the Evolution to achieve 9.31 mpg, it’s not far off the 10 mpg target that Daum said raised some eyebrows when first predicted.

“The 10 mpg truck is not out of reach anymore,” Daum said. “It’s a huge step and every step gets more difficult than the step before, but I still believe during my professional lifetime (the goal will be reached).”


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