MOST FLEETS ALREADY KNOW the negatives associated with 2007 engine technology that's designed to reduce emissions: higher engine cost; required exhaust aftertreatment technology; ultra low sulfur diesel (ULSD) fuel; reduced fuel economy; reduced oil drain intervals; and higher cooling requirements. All of that adds up to a bigger hit on the bottom line for refuse fleets and over-the-road freight carriers using diesel-powered trucks. But with winter tests wrapping up and summer engine testing about to begin, there are significant bright spots in '07.

Far more testing has been and will be conducted on the engines and related systems, compared to their 2002 and 2004 compatriots. Pilot testing on '07 engines will occur under real world conditions, a chance fleets did not get with earlier products.

The longer testing lead times for '07 engines also have allowed most truck manufacturers to piggyback vehicle redesign efforts onto the '07 development process. That could reduce the fuel economy and weight penalties that occurred with '02 and '04 products.

Moreover, with engine, truck and emission control system manufacturers working together, maintenance headaches and performance bumps are being smoothed out, creating more integrated vehicles that should comply with the emission rules as well as minimize the effects on their bottom line.

“I have heard the ‘doom and gloom’ prophesies for 2007 and frankly, these dismal forecasts do not have to come true,” says Rainer Schmueckle, former president and CEO of Portland, Ore.-based Freightliner LLC and now COO of Stuttgart, Germany-based DaimlerChrysler's Mercedes-Benz group.

“I have great confidence in '07 technology, largely because our preparation is way ahead of where we were at the same point before the 2002 deadlines,” he explains. “No doubt the '07 engines and related systems will be more expensive. But I do not expect customer operational costs to go up more than 2 percent.”

Rules of the Road

Schmueckle's confidence notwithstanding, meeting the '07 emission rules developed by the Washington-based U.S. Environmental Protection Agency (EPA) is no easy matter. The regulations cover more than just engine emissions.

According to Greg Gauger, director of on-highway power systems for Peoria, Ill.-based Caterpillar, the '07 rules will affect engine design in five areas.

First, a tenfold particulate matter (PM) reduction is required — from 0.10 to 0.01 grams per horsepower per hour (g/hphr). To meet this requirement, engine manufacturers need to use diesel particulate filters (DPFs) to remove PM from the exhaust stream, he says.

Second, nitrogen oxides (NOx) and hydrocarbon (HC) emissions also need to be cut, dropping from 2.5g/hphr NOx + HC to 1.2g/hphr NOx. This 1.2 figure is based on the phase-in provision, allowed by the EPA, as a step to cutting NOx emissions to 0.20 g/hphr by 2010.

Third, crankcase emissions, which are airborne substances emitted into the atmosphere from any part of the engine crankcase's ventilation or lubrication systems, will be regulated as exhaust emissions. They, too, must meet the '07 rules. Under the '02 and '04 rules, they were left alone.

Fourth, engine manufacturers will be required to monitor the performance of engine emissions systems in 2007 using an industry standard, called engine manufacturer diagnostics (EMD), Gauger says. EMD is supposed to detect issues within the emissions control system and ensure the engine and aftertreatment package is reducing exhaust emissions to the proper levels.

Finally, the 2007 standards regulate the useful life of engine emissions systems. It is set at 435,000 miles for engines powering heavy-duty trucks and transit buses, and 185,000 miles for mid-range diesel engines.

Meeting all five parts of the 2007 rules is a tall order for truck engine makers, but they all believe it is achievable.

“The 2007 rules pose a formidable challenge in terms of emissions reductions, but we are confident engines will not only provide cleaner air to breathe, but will continue to meet the very high demands our customers have for reliability, fuel economy and performance,” says Peter Karlsten, president and CEO of Greensboro, N.C.-based Volvo Trucks North America.

The Technology Choice

There are several major diesel engine manufacturers serving the U.S. truck market, including: Detroit Diesel Corp. (DDC), Renton, Mich.; International Truck & Engine Corp., Warrenville, Ill.; Volvo; Cummins, Columbus, Ind.; and Caterpillar. All have completed substantial internal prototype testing on '07 products, and the companies now are preparing prototype and pre-production engines for fleet field tests starting in late 2005 and through 2006.

All of the engine makers, except one, are using cooled exhaust gas recirculation (EGR) technology to reach the emission targets set by the 2007 rules. In this process, exhaust gas is cooled down and refunneled back into the combustion chamber of the engine along with the addition of a DPF of some type.

Caterpillar is using a different process. The company's “advanced combustion emissions reduction technology” (ACERT) is designed to recycle exhaust gas from different points in the exhaust stream. Clean gas induction (CGI) then will draw clean inert gas downstream of its particulate filter and put it into the engine's intake air system.

For fleets, the important point is that both EGR and ACERT form the foundation for reducing emissions in '07 as well as previous '02 and '04 targets. In other words, the basic technology being used today to reduce emissions will be used tomorrow as well, but will be refined by several more increments.

That will give fleets a more robust, better tested, and more “tuned” engine as a result, says Tim Tindall, director of emission projects for DDC. “Fortunately, the modifications to our engines will not significantly impact our product line-up,” he says.

To date, all of the engine OEMs are testing their 2007 products and are preparing them for field exercises with customer fleets.

DDC

DDC is a subsidiary of DaimlerChrysler, which also owns Freightliner. DDC is responsible for its Series 60 engine as well as the Mercedes-Benz MBE 4000 and Mercedes-Benz MBE 900. According to Tindall, all three engines will accumulate more than 25 million test miles, providing feedback that will help refine '07 products.

Winter testing has concluded on all three of the company's '07 engines. Preparations for summer testing are underway, and DDC plans to deliver the first in a series of more than 75 trucks with 2007 Series 60 engines to its strategic customers by the third quarter of this year. Although DDC will use a DPF, the exact type that will be deployed for 2007 has not been decided , according to Carsten Reinhardt, DDC's president and CEO. “What I can tell you is that it will not be a ceramic-based filter,” he said.

DDC is also planning to roll-out a new engine line to replace the Series 60 after 2007, in part to develop a better platform to meet the 2010 rules and what may lie beyond them.

“There's an old German proverb that says, ‘if you rest, you rust,’” Reinhardt says. “The Series 60 has had a 20-year career. It can comply with '07, but we need to look beyond that. We're going to have a new engine family with 14.8-, 15.6-, 12.8-, and 9.9-liter displacements with better optimized engineering to meet all future emission regulations.

Cummins

Cummins Engine Co., by contrast, already has lined up its DPF selection for its 2007 engine package — largely because it is conveniently designed by a Cummins subsidiary, Fleetguard Emission Solutions.

In addition to its EGR engine platform, the Cummins Particulate Filter is designed to reduce particulate matter emissions by 90 percent from current levels. The filter also is designed to replace the existing vehicle muffler, adding minimal weight to the vehicle. Service requirements will be extended as far out as 400,000 miles for line-haul operations, minimizing the operating cost for trucking companies.

Tom Kieffer, Cummins' executive director for marketing, adds that the company's 2007 engine also will feature a crankcase ventilation system from Fleetguard that is designed to eliminate oil carryover from the engine.

“We said that cooled-EGR emissions technology would be the foundation for our 2007 product line back in 2002,” Kieffer says. This “assures customers that the engine they are operating today will be the same basic engine in 2007,” he adds.

He notes that recently completed high-mileage durability evaluations of Cummins' on-highway ISX engine used in North America — engines totaling some 600,000 miles of commercial service — confirmed projections that the engines certified and compliant to the 2004 U.S. EPA emissions standards would have equal or better durability than the engines they replaced.

He also says that engine durability is typically defined as the point requiring an in-frame engine overhaul resulting from excessive component wear or oil consumption. These high-mileage evaluation engines were fully disassembled and all major components, from the crankshaft to the EGR subsystem, were analyzed. The company's engineering analysis confirmed both the integrity of oil control and combustion control, with components exhibiting normal and expected wear, he says. Power cylinder components showed only 20 percent to 25 percent wear after 600,000 miles, with connecting rod and main bearings expected to have 50 percent additional life remaining.

International

On the heels of winter testing on its 2007-compliant I-6 and V-8 medium-duty engines in a variety of company-owned test vehicles — medium-duty trucks (with and without bodies); several school buses; and Class 7 tractors — International is learning what areas need more attention, says Mark Stasell, vice president of engineering and product development for the company's engine division.

“We're particularly focused on learning about how to regenerate the particulate filters,” he says. “We want to use as much passive regeneration as possible [using heat from the engine to reduce particulates trapped in the filter to ash], but we're finding — as expected — lightly loaded, stop-and-go, low-speed truck applications require more active regeneration, which burns more fuel.”

However, International has determined from its initial winter tests that one of its main goals for '07 engine performance — neutral fuel economy impact — is achievable. “It's a challenge, for sure, but from what we are seeing, it can be achieved,” Stasell says.

Summer testing now is underway. By September 2005, 28 of the company's '07 engine prototypes will enter field tests with customers, Stasell adds. “We're going to look at getting durability and ‘transparency’ feedback — how easy it is to use — about our '07 package from customers,” he notes. “We're also going to do more winter testing in 2006.”

In the meantime, International is looking at how the introduction of ultra low sulfur diesel (ULSD) fuel in 2006 could be a boon to the long-term durability of low-emission engine designs.

“One of the concerns we had when we started working with EGR technology is that by recirculating and cooling down hot exhaust gases, we might be creating more ideal conditions for the formation of sulfuric acid,” says Patrick Charbonneau, vice president of regulatory and technology affairs for the company's engine division.

Highly corrosive sulfuric acid can form as a result of mixing sulfur particles in the exhaust stream with water condensation created from the cooling process, he explains. However, by substantially reducing the amount of sulfur in the fuel — from today's sulfur content of 500 parts per million (ppm) down to 15 ppm next year — Charbonneau believes the chances of sulfuric acid formation will be substantially reduced.

“Theoretically at least, the sulfur amount in the exhaust stream should be extremely low, and thus the EGR systems being exposed to it should benefit,” he says. “But it's a fine line here that we have to document. In theory, ULSD should enhance the durability of EGR systems, but we test data to truly confirm it.”

Jack Allen, president of International's engine group, adds that the company plans to offer a proprietary emission-compliant, heavy-duty engine in the 11- to 13-liter range in fall 2007 that will be designed in conjunction with MAN Nutfahrzeuge, a German engine manufacturing company. However, Cummins and Caterpillar products will remain options.

“Our new engine will be specifically engineered to integrate diesel technologies with cab, chassis and systems innovations,” Allen says.

Volvo

Volvo plans to use EGR and DPFs on a new family of engines scheduled for introduction in 2007. Additionally, 30 engines with '07 systems are expected to be field-tested with select customers this spring. The technology will be shared with its Allentown, Pa.-based subsidiary Mack Trucks.

“Volvo's experience with EGR to date demonstrates that … customers are already familiar with EGR and have accepted it as a reliable, everyday part of their operation. We intend to have our EPA '07 engines in field testing as soon as possible … so that 2007 becomes a seamless transition.”

Paul Vikner, CEO of Mack, says the key is to address trucking industry vehicle needs during the next five to six years as a whole — emissions, driver comfort, maintainability, etc. It should be perceived in such as way so that customers do not feel a need to “pre-buy” trucks prior to the '07 deadline because they are not confident in the emission control technology and engine reliability, he says.

“There will be some pre-buy to a degree, but that is going to depend on how we as manufacturers address customer concerns about that technology,” Vikner says.

Cat and ACERT

Caterpillar's '07 package will combine ACERT — which includes series turbochargers, variable valve control, a high pressure multiple injection fuel system, electronics control systems and an oxidation catalyst, — with an enhanced combustion process called clean gas induction (CGI), closed crankcase ventilation system and diesel particulate filter system with active regeneration.

Mid-range Caterpillar engines also will build on ACERT and feature a high-pressure injection system and the closed crankcase ventilation, with the addition of a variable turbine geometry turbocharger, Gauger says.

He adds that the company's diesel particulate filter solution for '07 uses a wall-flow filter, using active regeneration to initiate a process of oxidation to eliminate the soot that collects along the inlet walls of the filter. “To aid the regeneration process, the exhaust gas is heated by auxiliary means,” he says. “Regeneration only takes place when needed, which optimizes fuel economy. Engines with 500 horsepower or less will require one diesel particulate filter; engines with 550 or more horsepower will require dual filters.”

Not only are oil change intervals and sump capacity expected to remain unchanged from today's ACERT engines, but the '07 models will be designed to maintain the same ratings as well, he says. “We expect that our heavy duty engines with ACERT Technology for 2007 will maintain the same fuel economy as today's engines, and our mid-range products will improve by approximately 4 percent,” Gauger adds.

To date, 200,000 ACERT engines are on the road accumulating 68 million miles per day. The heavy-duty '07 engine package will be placed in the hands of customers in two waves — the first in the second quarter of 2005 and the second during the fourth quarter. Mid-range '07 engines will be distributed for customer tests in the first quarter of 2006.

Ready to Roll?

The real issue for all the engine makers is the availability of ULSD next year. By federal mandate, 80 percent of the on-road diesel fuel sold in 2006 must have a sulfur content of no more than 15 parts per million (ppm), down from the current 500 ppm standard today.

Gauger says refineries plan to start producing ULSD by June 1, 2006, meaning it should reach the retail market in sufficient quantities by Sept. 1, 2006.

“The sulfur content of the fuel is the real issue,” he says. “Because sulfur in the fuel tends to damage the DPFs, all [manufacturers] plan to use [low-sulfur fuel] to control emissions. That's why we really need 15 ppm fuel or lower to make emission control work,” he says.

Sean Kilcarr is senior editor for Waste Age's sister publication, Fleet Owner.