Hybrids hit the road

April 1, 2009
Hybrids are happening. These alternative-powered commercial vehicles are now appearing up and down the GVW scale, making it likely one is available now or will be soon for an application near and dear to your fleet. True, be they electric or hydraulic based, hybrids still account for a mere fraction of new truck sales. But they are being offered by more and more OEMs and in more configurations than

Hybrids are happening. These alternative-powered commercial vehicles are now appearing up and down the GVW scale, making it likely one is available now or will be soon for an application near and dear to your fleet.

True, be they electric or hydraulic based, hybrids still account for a mere fraction of new truck sales. But they are being offered by more and more OEMs and in more configurations than just months, let alone years, ago.

So, why is there an explosion, not just in interest but in product development and actual vehicle rollouts? The short answer, counterintuitive as it may be, is that it's not thanks to the price of diesel. The long answer, according to suppliers, is a market for them has emerged because they are making solid business cases for why hybrid-powered trucks are the right fit for various trucking applications.

Hybrid system suppliers and truck OEMs are rolling out an ever-growing roster of hybrid trucks largely distinct by their duty cycle — and that's what's driving their business cases. And, at this point anyway, no one is knocking anyone else's technology choices because the field to conquer is wide open and because it is obvious that different hybrid solutions smartly fit different truck applications.


Before jumping into hybrids, pause for a moment and contemplate what is coming down the pike next: electric trucks.

Like hybrids, full-battery, electric-powered trucks will be most suitable for certain applications, such as P&D, which is seen as an early candidate for electrification.

But the arrival of electric trucks won't forestall the continuing rise of hybrids. Whether each drive technology — and its suppliers — deliver on its potential will ultimately be determined by truck buyers.

Here is a general and not-too-technical definition of just what is a hybrid: a drive system using a combination of energy sources, such as an internal combustion engine, batteries and an electric motor, to drive a motor vehicle

According to the Vancouver, BC-based nonprofit Fraser Basin Council, with a parallel hybrid, the battery and engine are both connected to the transmission — so either the battery via the electric motor, or the engine directly to the transmission, or a combination of both can provide power. With a series hybrid, the engine turns a generator, which can either charge the batteries or power an electric motor that drives the transmission; the engine never powers the vehicle directly.

Right now, fleets can pick from hybrids falling into three distinct categories: diesel-electric, diesel-hydraulic, and hydraulic assist (for diesel) — a sort of "partial" hybrid in layman's terms.

One or more of these hybrid types, either in full release or far along in their development cycle, will match up with one or more of these truck applications:

  • Package delivery/step van

  • City P&D/straight truck

  • Utility/work truck

  • Beverage/tractor and truck

  • Reefer/truck

  • Refuse/low-cab-forward

  • Linehaul/tractor

  • Yard/tractor

Does the emergence of all these application-specific vehicles available constitute hybrids being a market of their own or just a side line for some OEMs?

According to Kevin Beaty, hybrid business unit manager for Eaton Corp., which is currently the largest provider of truck hybrid-drive systems, the market for hybrid trucks is "at the tipping point," evidenced by both repeat business and increased order volume.

"For example," relates Beaty, "FedEx put 14 diesel-electric hybrids into its fleet in 2004, and they followed up with another 75 in '06 and 45 in '07. That last order reflected a budget restriction. But FedEx is definitely past the 'try-it-out stage,' as this year it's expected they will order almost 100 units."

Beaty says the expectation is that most existing hybrid customers will make "repeat purchases with higher volumes" each time and the only "restraint" he sees is the per-unit purchase price, which will drop as production volumes rise.


"Hybrids are expensive," he states. "OEMs charge premiums of $40,000 to $50,000 for this technology because the economies of scale are not there yet [in terms of unit orders].

"However," Beaty continues, "there are both $3,000 and $12,000 federal tax incentives hybrid buyers can take advantage of" as well as grants. He adds that more substantial government incentives would boost purchases and thus bring the OEM premiums down over time.

But Beaty also points to other aspects of the business case that can be made for selecting hybrids. "The fuel savings are dramatic, so that is a driver. And many fleets are selecting hybrids in keeping with their green and energy sustainability initiatives."

He notes that trucking-wide hybrid capacity hit the 2,000-unit mark last year and says that "as a Tier One supplier, Eaton would be looking for production of 5,000 to 10,000 units yearly to hit cost targets attractive to the industry … so buyers would not have to pay above and beyond what fuel savings alone will justify" to purchase hybrid trucks.

Beaty points out, however, that due to their high-idling duty cycles, diesel-electric hybrid utility trucks "do drive a better payback in terms of fuel saved, which can be as short as eight years."

Robert Golin, HLA business lead for Eaton's Hydraulics Group, says its HLA (Hydraulic Launch Assist) is a parallel hybrid system offering a specific and compelling "value proposition" for both rear- and side-loading Class 8 refuse trucks. He says the HLA will improve fuel consumption and reduce brake wear in heavy stop-and-go operation by making use of the energy normally lost to braking. But what's more, by leveraging that kinetic energy, the system provides an 8 to 10% acceleration benefit, which means 1.5 seconds can be gained per trash bin emptied.


"That adds up when a truck is collecting from 1,000 bins a day," Golin points out. "It means the truck can pick up, say, 80 to 100 more bins on a route. The HLA delivers faster collections, less fuel consumed, fewer brake jobs and results in the diesel engine being used less," he continues.

Given all that and "without any federal tax credits, we figure there will be a two-and-a-half year payback for HLA on a refuse truck that will have a 10- to 12-year life."

Golin says that Eaton's HLA was itself launched by Peterbilt on its Model 320 low-cab-forward truck aimed at refuse applications. He relates that Eaton is working with UPS on a Class 3-7 diesel-hydraulic hybrid in which a hydraulic pump will replace the transmission.

According to Golin, this hybrid will bring a "constant-variable" gear-changing concept into play that will engage the engine at its sweet spot, and it will boast an "idle-off feature" as well.

Like Eaton, Parker Hannifin Corp. is also focusing on refuse vehicles, but with a system it describes as a hydromechanical series drive designed to significantly reduce fuel consumption and increase productivity for vehicles in applications with a high stop-and-start rate in severe-duty service.

"Based on the feedback we've received to date, we are confident Parker's advanced series hydraulic hybrid technology has real potential to significantly improve the fuel efficiency, productivity, and environmental footprint of refuse and similar heavy trucks," says Vance Zanardelli, manager of Parker's Energy Recovery Business unit.

Zanardelli says Parker's system for refuse trucks replaces the truck's conventional transmission with a hybrid drive that "marries the variable features of a hydrostatic drive, which is ideal for urban routes, with the efficient performance of a mechanical drive that performs best at highway speeds."

He says refuse vehicles equipped with Parker's hydraulic hybrid system have achieved fuel savings of 30 to 50% during track testing and actual field trials of refuse-collection cycles. "Reduced fuel consumption, a corresponding reduction in emissions, substantially reduced brake wear and improved off-the-line acceleration are all benefits of the Parker hybrid drive system."

Zanardelli relates that currently Parker is evaluating prototype vehicles through a variety of acceptance tests that replicate the real-world operation of refuse trucks.

ArvinMeritor recently presented Wal-Mart Stores Inc. with a prototype Class 8 tractor equipped with the first Meritor diesel-electric hybrid drivetrain. Wal-Mart Transportation will test and evaluate the truck in regular linehaul service at one of its distribution centers throughout 2009.

"While most hybrid systems today are best suited for start/stop applications, our hybrid drivetrain is specifically designed for linehaul, over-the-road trucks, the largest segment of the commercial vehicle population," points out Carsten Reinhardt, president of ArvinMeritor Commercial Vehicle Systems.

The Meritor hybrid drivetrain being tested at Wal-Mart was developed in collaboration with Navistar and Cummins and is comprised of a proprietary motor/generator unit and high capacity lithium ion batteries, as well as an overall power-management system.


According to Chad Mitts, ArvinMeritor's director of advanced technology, "the Meritor dual-mode hybrid drivetrain" combines mechanical and electrical propulsion systems. Under 48 mph, vehicle propulsion is provided entirely by an electric motor with power drawn from lithium ion batteries. These batteries are recharged through regenerative braking and/or an engine-driven generator. As the truck approaches highway speed, the drivetrain "phases" to a diesel-powered system with the electric motor providing power only as required, which Mitts says "allows for total system optimization."

He explains that the key differentiator of the system is its ability to run in "zero-emissions mode" over a wide range of driving conditions. "This allows the truck to operate in places where emissions are restricted, like a port or urban area," he points out.

Mitts says the batteries provide continuous electrical power for hotel loads during overnight rest periods, eliminating the need for engine idling or redundant anti-idling systems, making the hybrid case more appealing for long-haul operations.

According to Mitts, ArvinMeritor is also working on a "full-battery electric" system focused on medium-duty P&D applications. This project is under development jointly with Purolator, Canada's largest overnight package courier, and Toronto-based chassis maker Unicell Ltd.

A prototype fiberglass-bodied Quicksider van was placed in Purolator's fleet in late 2007. Mitts points out that for this application, using electric drive enables redesigning the entire chassis for greater operator productivity — with flat floors and a "kneeling" function at the door — as well as zero emissions. "Unicell was instrumental in pushing forward what was a clean-sheet design," he adds.

"Production for both our heavy-duty hybrid and medium-duty electric drive is a couple of years off," says Mitts. "For the full electric, battery packs remain a critical piece of the puzzle. And it is a significant challenge to develop a hybrid for over-the-road Class 8 applications."

As Mitts puts it, the first diesel-electric hybrids were developed to "pick the low-hanging fruit" for this technology, which were the bucket trucks operated by utilities nationwide due to their high-idling PTO requirements.

"But the long-haul truck market is large and fuel consumption is high for these operators," Mitts observes. "Given the length of miles traveled by these fleets, hybrid drivetrains can have a positive impact on operating costs."

He says the upshot is more developmental work is required than what it took for early hybrids, "but we feel we have a strong value proposition" for the Class 8 hybrid. "The drop in fuel consumption is tremendous, and Wal-Mart viewed the project as aligned as well with their overall green mission."

Mitts says that while this "first generation" highway hybrid is being spearheaded by ArvinMeritor, it took on Navistar as an OEM partner. "Certainly, going forward [with this technology]," he adds, "we expect OEMs will take a larger role" bringing trucks to market.


Be it a hybrid or electric truck, Mitts says market acceptance will come down to whether the given system can be matched with a specific duty cycle and from there a value proposition should be figured.

Truck OEMs already offering or working on hybrid trucks of one sort or another include Daimler Trucks North America (Freightliner and Freightliner Custom Chassis Corp.), Kenworth, Mack, Navistar and Peterbilt.

Mack Trucks director of media relations John Walsh says the OEM is "confident we have optimal hybrid technology — an integrated starter, alternator and motor that makes it possible to use energy captured during braking and stored as electricity not only to launch the vehicle, but also to power auxiliary equipment on the truck such as key-off hydraulics, further maximizing fuel savings.

"One of our core market segments, refuse, with frequent stop-and-go driving, is an ideal application for this technology," he continues. "We've been working with the U.S. Air Force on heavy-duty hybrids, and we're also on the verge of delivering additional units to commercial customers for evaluation. We plan to have the technology fully commercialized, with trucks available for retail sale, by mid-2010."

Walsh says that Mack is seeing the greatest interest in hybrids from its refuse customers, as "fuel economy improvements of up to 30% are possible. And a reduction in fuel consumption results in a corresponding reduction in CO2 emissions. This type of hybrid will be sought out by states, cities and municipalities that are in EPA non-attainment zones."

Jonathan Randall, director of sales and marketing for Freightliner Custom Chassis Corp. (FCCC), says the supplier of stepvan chassis got its feet wet in the hybrid market back in 2000 with the first Eaton diesel-electric hybrid prototype truck it placed in the FedEx fleet.

That led to FCCC offering a diesel-hybrid, stepvan chassis as a regular production unit. Mike Stark, alternative fuels & national accounts technical sales manager, points out the diesel-electric model now boasts an idle-off feature that boosts fuel economy 8% — on top of the 40% improvement the first units delivered — which is substantial in a traditional stop-and-go stepvan application.

"Taking into account fuel economy and longer brake and engine life, we're able to show an ROI in eight years or so for a stepvan running 8,000 to 30,000 mi. a year in stop and go," says Stark, "and that's for a vehicle with an average life of 15 to 20 years. We do see pricing going down as we continue to work with our suppliers, and there are federal and state tax credits that may apply." He adds that the diesel-electric hybrid is "no longer a special order, but an option on all our trucks."

Randall reports FCCC has also rolled out a hydraulic hybrid pilot vehicle using a Parker drive system. "It's aimed at the same vocational target as our diesel-electric," he explains. "The technology is not hydraulic assist, as on a refuse truck, but a series hydraulic system.


"Now being tested by FedEx Ground," Randall continues, "this system has an advanced engine-off feature that combined with the unit's power density results in greater fuel efficiency than our diesel-electric hybrid truck."

Randall says the hydraulic does not obsolete the electric hybrid, noting that FCCC is "pursuing both" and regards the hydraulic as still in the pilot stage.

Navistar's Josh LePage, sales manager, product integration-International Truck, states that hybrids have "definitely moved past the trial stage. They've been production line assembly for us since December 2007." He says the early adopters have been fleets that "grasp the technology as environmentally conscious truck operators as well as those with trucks that make a good business case for using hybrids."

LePage says diesel-electric hybrids are well-suited to utility and other work trucks as well as stop-and-go delivery trucks, especially those like beverage haulers that have "diminishing" loads as the workday goes on.

"Refuse trucks are also seeing hybrid activity," he continues. He says diesel-electric does not fit the severity of this duty cycle, but hydraulic does, noting that a "'full' hydraulic series hybrid system is under development" for International trucks in partnership with Eaton and Bosch Rexroth.

"There's no target launch date yet, but the waste industry is chomping at the bit for these hybrids," says LePage, "which comes back to the point that acceptance is being driven by making a business case for the customer."

LePage says that by leveraging federal tax credits as well as local and state grants, fleets can greatly enhance the hybrid ROI.

"Factoring in the high-idling application and tax credits, when diesel was up around $4.50/gal., the payback on a diesel-electric utility truck was less than three years. Now, with fuel at around $2.50, the utility payback is five years and it's about eight years on other applications, such as city delivery."

"Our Eaton-based diesel-electric hybrids started out with a narrow focus — 'bucket' and city-delivery trucks — but now they are finding their way into more and more applications," says Andy Douglas, national sales manager-specialty markets for Kenworth.

Douglas says Kenworth aims at four basic hybrid applications: P&D, PTO Utility, Beverage Body and its most recent introduction, a single-axle tractor with 55,000-lb. GCWR, also for beverage delivery.

He notes the OEM recently built a hybrid service-body truck for one construction firm and advises that other PTO applications are well-suited for a diesel-electric drive truck.

"We've done testing on a Class 8 hybrid highway tractor as well," says Douglas. "There's no plan to offer such a product at this point. When you get to 80,000-lbs. GCW, there are new challenges to meet. We are also looking at hydraulic-launch systems and other technologies as well.

"The key thing about hybrids," he adds, "is the technology is sound. In no way is what's being offered a 'science project.' These are robust, market-ready trucks."

Landon Sproull, chief engineer of Peterbilt, contends that for electric and hydraulic hybrids together, there are "in reality hundreds of different truck applications" possible.

He points out Peterbilt already offers Class 6-7 trucks and a Class 7 tractor fitted with a diesel-electric hybrid drive for medium-duty service and a low-cab-forward HLA hydraulic hybrid for vocational stop-and-go applications, such as refuse collection. Both the electric hybrid drive and the hydraulic launch assist the OEM uses are supplied by Eaton.

According to Sproull, Peterbilt is also looking at the highway market for diesel-electric hybrids. "We've just placed five Model 386 aerodynamic electric-hybrid tractors into Wal-Mart's fleet and one into the UPS fleet. These are the only heavy-duty Class 8 hybrids for highway service.

"These trucks are part of our R&D effort to gather information on duty cycles to help us refine the [hybrid truck] design to attain 5 to 7% better fuel economy," says Sproull.

As for where both electric and hydraulic hybrids are ultimately headed, Sproull says it will be all about the applications. "There's no downside with hybrids," he says, "but the payback depends on the duty cycle of the truck."

"With fuel prices currently at relatively low levels, hybrids might not be as front and center as they were just a year ago," remarks Mack's Walsh. "But when global economic conditions improve, and demand for fuel increases, diesel prices are sure to rise again — further enhancing the value proposition of hybrids."

The message is clear: Hybrids are here and gaining ground, meaning fleets will be able to choose from more and more of them that will fit a growing roster of applications.

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