The emissions dividend

No one denies that federal regulations have greatly reduced diesel engine emissions over the past 15 years. While that’s an achievement widely applauded, it’s also generally acknowledged that those same regulations have added greatly to the cost of a new truck. And for many fleet owners, the perception is that while society as a whole has gained much from their cleaner engines, the cost has come with little to no benefit for their businesses.

With the perfect vision that comes with hindsight, it’s time to revise that perception. Yes, emissions systems may have added as much as 30% to the price of a new truck over the last decade and a half. But if you look beyond the smokeless tailpipe, it turns out that development of these advanced emissions controls are paying significant dividends in a whole range of other areas that do, directly or indirectly, have a positive impact on any trucking business.

Most of the discussion up to this point has focused on how the evolving emissions technology has cleaned up diesel’s exhaust, with EPA 2010 standards bringing those emissions down to levels that seemed impossible just 10 years ago. Now that we’ve crossed that barrier, let’s take a look at what else has been gained by the hundreds of millions of dollars spent to achieve such ultra-clean emissions.


Improvements made to diesel powerplants to meet the successive rounds of EPA truck-emissions regulations are credited by all North American engine suppliers with helping to both extend engine life without major overhauls and increase engine reliability for less service downtime.

“The main changes to diesel engines that have been made to improve durability and reliability is cleaning up emissions outside of the engine, i.e., via selective catalytic reduction [SCR],” points out Brad Williamson, manager-engine & component marketing, Daimler Trucks North America (DTNA).

“ In the late ’90s and early 2000s, with the introduction of exhaust gas recirculation [EGR], engine manufacturers were ‘forced’ to clean up the emissions ‘inside’ the engine, which reduced engine efficiency and created more stress on internal components. In terms of reliability, many of the issues were a direct result of the additional componentry necessary to meet emissions requirements, such as EGR valves, delta p sensors, etc.”

Williamson says this state of affairs continued until 2010 “when most engine manufacturers turned to SCR technology to ‘reverse the negative effects of EGR’ and enable the engines to run more optimally.”

He says use of SCR should increase engine durability and reliability. “We have seen from industry gatherings that 2010 engines are receiving higher ratings on durability and reliability than previous 2004/2007 engines initially did over the long run.”

Williamson does add that “many of the manufacturers’ B50 or B10 measures have remained unchanged for years.” B50 and B10 are engineering measurements of durability, which equate to the time by which a percentage—in this case, 50% or 10%—of the population of a given product will have failed.

Million Miles

Tim Shick, International’s vice president-North American engine sales, points out that since the first round of commercial-vehicle emissions rules were rolled out back in 1988, engine durability as well as performance and fuel economy have been improved “as a result of the evolution of heavy-duty diesels, a large part of which has been emissions-driven.” He adds that some of the gains “would have happened anyway, but they would not have progressed as quickly as they have.

“There’s no Class 8 2010 engine out there now that’s not capable of getting a million miles as long as it gets good care by the book, per OEM recommendations,” Shick continues. “Hard to think, but it was 20 years ago that the industry first spoke of maybe reaching that milestone.”

He points to several reasons why a 2010 engine holds the key to such a potentially long life. “Engines today are made to more exacting tolerances and they have much better oil control, the need for which was brought on by emissions rules. There are advanced lubes available today, thanks also to emissions requirements, and they do a better job of holding contaminants in solution. These oils include synthetic formulations, which are increasingly being used by top fleets.”

“We introduced our new engine—the Paccar MX—last year and our experience with its reliability is excellent,” says Landon Sproull, chief engineer for Paccar’s Peterbilt Motors Co. “We can tout a B10 life of one million miles, which means 90% of these engines can reach that point without needing a rebuild. We don’t have engines out there yet with that much mileage, but we have spoken to a few key customers running them 300,000 miles a year so we have some with almost a half-million on them already. Next year, we will see the first customers hit a million miles with an MX.”

Sproull notes that elements of the MX design that contribute to longer engine life include the size of components in the “bottom end” of the engine, most notably a larger crank and camshaft. “Manufacturing tolerances are also tighter and building the head from compact graphite iron has both helped to reduce operating noise and added strength, as has the use of high-strength steel inside the engine.

“And from a reliability standpoint,” he adds, “2010-spec engines, including those supplied to Peterbilt by Cummins, are so much better than engines available in the 2008-’09 timeframe. The reliability of engine aftertreatment systems has also improved as the industry has gone through—since EPA ’07—learning about the role of diesel exhaust fluid [DEF], system sensors and SCR working together.”

Engine Evolution

Engine life and reliability have been improved thanks to “using the right technology to attain emissions control, improve fuel economy, and increase reliability and durability,” says Dave Brush, heavy-duty program leader for Cummins. “For our 2010 engines, this translates to a million miles without an overhaul as well as increased uptime for our customers.

“Hardware technology for today’s heavy-duty engines includes blocks and heads constructed of higher-strength materials to deal with higher loads and liners hardened to be compatible with the use of EGR,” he continues. Brush also points out that improvements made to improve oil control and consumption help lengthen engine life, that camshafts and roller bearings have been improved for greater durability, and that the evolution of pistons to today’s mono-piece design also contribute to longevity.

“The industry is now realizing the benefits of 15 to 20 years of engine evolution,” points out Tom Grana, Cummins’ director of heavy-duty aftermarket. He says another key dividend is that engines are now more frequently being operated with lower-viscosity motor oils, which help improve fuel efficiency.

“We monitor our engines’ reliability very closely,” says Brush. “The reliability of our 2010 engines is better than that of the 2007s. And our 2013-spec engines will be better than the 2010s.” As for 2013, he relates that emissions rules set to come in effect then will require all heavy-duty diesels to have onboard diagnostics (OBD).

“The arrival of the OBD represents a fairly significant industry-wide effort,” says Grana. “Per EPA and CARB [California Air Resources Board] rules, we have OBD on one of our 2010 engine families, but the systems will be required across the board in 2013. The regulators’ motive for OBD is emissions compliance, but having it in place provides other benefits thanks to its sophisticated diagnostics.”

Grana explains that with an OBD hooked up, any performance “lags” of the engine can be electronically detected well before the driver can sense them. The upshot is “repairs can be arranged for and completed before the engine is damaged.”

According to Ed Saxman, Volvo Trucks’ drivetrain product manager, with the advent of 2010 technology, “millionmile engines are certainly here. The dimension of parts inside the engine has helped increase engine robustness. For example, today in the bearing area, the connecting rod of a Volvo 13L engine is the biggest except for that of a Volvo 16L.” He notes that Volvo Trucks “does not publish B-ratings of engine life as they are engineering estimates.”


Engineering work required by the successive rounds of EPA truck-emissions regulations culminating in today’s EPA ’10-certifed engines have also enabled engine makers to boost both the fuel efficiency and the on-the-road characteristics of truck diesels.

Peterbilt’s Sproull points out that moving from EPA ’07-certified engines to those certified for 2010 using SCR has provided a “major advantage as that aftertreatment solution enabled us to recalibrate the engine to improve fuel economy by up to 5%. We can literally ‘run’ the engine like it was in the 2004 timeframe [in terms of fuel efficiency and performance] and clean the exhaust with SCR.”

He says turbochargers have also been improved to better match engine characteristics to both help with meeting emissions criteria and bettering fuel efficiency.

Also contributing to improved performance are the enhancements made to the engine control module (ECU)—the electronic brains of the powerplant—in recent years. “Codes used by the Paccar MX engine’s ECU allow us to provide it with a torque curve that ‘pulls’ at low rpms for better fuel economy,” points out Sproull.

“Customers have commented that the torque curve of 2010 engines lets them haul up a mountain with just a 13L engine as well as they did with a 15L one,” he continues. “That means they can enjoy a 300 to 400 lb. weight savings yet get the same performance. This spec is particularly appealing to bulk haulers. Low-rpm capability provides better fuel economy overall, especially running over the road.”

As for favorable driver response to 2010 engines, Sproull points both to the hill-pulling ability of today’s 13L engines as well as “how much quieter running the Paccar MX is compared to historical engines, which results in less driver fatigue.”

He says this quietness is attributed to the engine’s architecture and the selection of materials used to build it. Sproull adds that every engine Pete sells is “calibrated with the rest of the powertrain for maximum gradeability and startability.”

Volvo’s Saxman says engine performance has improved markedly starting with EPA ’07 and continuing to EPA ’10 engines thanks to changes achieved in power density. “For example,” he points out, “whereas a rating of 485 hp. at 1,650 rpm had been the most popular for a 13L engine, today that engine will be rated 500 hp. at 1,750 rpm. For a lightweight 13L to produce 500 hp. for customers who want it is a capability that the EPA ’10 emissions rule netted us.”

Tweaking Variables

He explains that running the 13L at 1,750 rpm “means we are gearing even taller. Downspeeding the engine requires more torque, which has been enabled by the use of diesel particulate filters [DPF] and the aftertreatment of NOx [oxides of nitrogen].

“For ’07,” Saxman continues, “all engines needed a DPF to remove soot and for 2010, [most] engine makers used SCR for NOx aftertreatment. Deploying SCR in turn enabled less need for EGR and that meant the engine produced less soot. And that made for greater responsiveness from the engine, including pulling up hills. With 2010 and the use of SCR came aftertreatment balanced for soot and NOx, and that benefit has contributed to better fuel efficiency of up to 5%.”

Saxman contends that “no truck buyer has to be scared of a 2010 engine. It will run great; the driver will be pleased with its performance; and fuel economy will be as good as ever or even better.” That being said, he adds that engine performance factors are “interwoven and engineers keep tweaking all the variables, such as peak cylinder pressure, via the emissions-control technology being used.”

Cummins’ Brush says that fuel efficiency is a “key factor for customers and therefore the “impact of using SCR cannot be overstated; it has enabled a 5% improvement in fuel mileage for 2010 engines. Having SCR lets the engine run more because the NOx is taken care of by the aftertreatment system. System engineering and system integration are not clichés,” he adds, but are key drivers of engine technology, which must comply with both emissions rules and customer expectations.

“The use of lower-vis oils benefit both fuel economy and cold-temperature starts,” advises International’s Shick, “but require the higher manufacturing tolerances seen in today’s engines. All of the advances to engines have been progressive, with each engine generation providing incremental performance gains. Along with the contribution of motor oil, improved engine fuel and air control has increased fuel efficiency. This includes bringing the air into the engine sooner via advanced turbocharging.

“There’s also a huge fuel economy and driveability benefit as today’s engines deliver more power at lower engine speeds than even ’07 and ’09 engines,” he continues. “Until the 2010 engines came out, torque of 1,650 rpm and up was limited to 15L engines. So while before a 15L engine was needed to get robust 400-plus hp. performance, with 2010 engines the industry has seen lighter 13L engines come into their own for mainstream linehaul power. For example, we offer a 13L with a 500-hp. rating and every engine maker has at least one with a 450-hp. rating.”

Shick adds that the power density characteristics of an engine and how responsive it feels to the driver are “somewhat related and the positive changes seen here with engines can be traced back to advances in both fuel systems and turbochargers.” He says it’s all about “bringing air into the engine at a higher rate and bringing fuel in at high pressure” at low engine speeds.

Cost of Ownership

You used to see black smoke coming out the pipe when a truck was going uphill,” he continues. “That’s because those [olderdesign] engines were starved for air and needed higher fuel pressure. Now that combustion is more efficient, engines produce lower emissions and provide higher fuel economy and performance for the driver.”

“The overall diesel engine has remained unchanged for decades, but the efficiency of the base technology has been significantly improved by the use of electronic calibrations, extensive testing, and the drive to deliver better fuel economy,” contends DTNA’s Williamson.

“Whether a customer has a 13L or 15L engine, many of these same practices have resulted in significant gains in overall cost of ownership,” he continues. “From extended service intervals to improved fuel economy, the relative cost to operate a diesel engine has been improving with the passing of time.” He says that DTNA’s Detroit engines are “now cleaner, more fuel-efficient, quieter and more productive than ever before. Our BlueTec SCR emissions technology reduces emissions and improves fuel economy. Combined with the Detroit vertically integrated powertrain, Detroit engines will continue to improve.”


Back in 2003 there were about 5,000 trouble codes for Class 7 and 8 trucks. After the development of sensors and controls needed to meet the substantial decreases in particulate matter and NOx mandated for 2004 and 2010, that number has ballooned to 28,000, according to Greg Reimmuth, vice president of sales and marketing at Noregon.

For example, the previous generation Detroit Diesel Series 60 engine had about 300 trouble codes, but the new DD13 has about 2,700, Reimmuth points out. “There are five times more sensors on the truck now. The enhanced electronics [that came with emissions systems] have clearly ramped up the quantity of data available,” he says.

Lee Lackey, Noregon’s director of technical sales, also chairs the SAE committee responsible for maintaining data standards related to the heavy-duty truck J1939 data bus. Over the last eight years, data on J1939 has doubled, he says, with most of that increased traffic attributable to emissions technology.

“There’s been a huge expansion in the amount of information, which brings a lot more complexity,” Lackey says. “But more data also helps technicians troubleshoot these complex systems more easily.”

Perhaps more importantly for truck users, more of that data has moved out of proprietary forms specific to the various engine makers, making “agnostic” third-party diagnostic systems like those developed by Noregon more functional. For fleets running a mix of power units, that means fewer brand-specific diagnostic tools for technicians to master. Although most focused on the sharp reduction in NOx, the 2010 EPA diesel emissions rules also included regulations requiring engine makers to share even more service-related information in publicly accessible formats. That portion of the rule doesn’t take full effect until 2013, but third-party diagnostic providers like Noregon are already working with manufacturers on what data will be shared and in what ways.

When automobile makers traveled down this route a number of years, they essentially opened all of a vehicle’s data to the public, but Lackey doesn’t believe that will be the case with heavy-duty diesels because of safety and security issues.

“The heavy-duty diesel has far more flexibility, allowing you to customize shift patterns, horsepower and other performance characteristics” through programming, he says. “So some data will have to remain proprietary, but there will be much more data available to third parties.”

However, just having more data isn’t in itself more valuable to truck owners. In the past, those critical trouble codes would light the engine warning lamp, prompting the driver to get immediate assistance from a technician who could read the code. “With all the codes being generated now, the driver would be pulling over constantly if they all were allowed to light the engine light,” says Reimmuth. “That doesn’t work for fleets last time I checked.”

Part of the solution has been to develop smarter diagnostics to use all that new data. For example, there is now a classification for “pending codes” used to store information that will let a technician know about a developing issue before it becomes a full-blown fault code requiring the truck to be shut down. There are also other codes that help technicians avoid unnecessary test drives to resolve emissions issues more quickly, according to Lackey.

Looking more broadly, this new wealth of vehicle data is also helping foster higher truck productivity. data delivers Fleet management systems are consumers of data of all kinds, says Dick Hyatt, president of Decisiv, a developer of service management systems. Having immediate access to specific vehicle operating data allows a service like Decisiv to remotely analyze probable required repairs. Combined with location and other telematics data, such a system can then make intelligent decisions about when and where those repairs should take place. The more precise the data, “the more actionable it becomes,” says Hyatt. With the new emissions data stream, “we’re getting more pinpointed and more relevant data, which means more actionable data and more efficient service events.

“Once we have that, we can open a dialog with the fleet and service locations,” Hyatt continues. “That gives you a higher likelihood that you’ll get the appropriate repair and also extract time out of the service event by making the process more efficient.”


At first glance, image seems like a relatively soft dividend with little impact on a fleet’s business goals. But after decades of being characterized by the general public as a “dirty” industry polluting our air with black, oily exhaust, today’s clean diesels are changing that image more quickly than expected. And that is having a direct impact on trucking.

A good indication of that change can be seen in a new public opinion poll conducted by MWR Strategies for the Diesel Technology Forum (DTF). Released in December, it tallied responses from just over 1,000 registered voters spread throughout the country. A resounding 62% said they believed diesel technology has gotten better over the last five years, compared to just 3% who felt it had gotten worse. A similar percentage said diesel technology is part of the country’s energy future.

More to the point, 56% indicated that they’d seen “a noticeable improvement in emissions from diesel trucks.” And 63% agreed that “making trucks more energy-efficient would be a better use of federal funds than explaining electric cars to consumers.”

“It was an even more positive opinion of diesel than we expected,” says DTF executive director Allen Schaeffer. “There was a higher recognition of the changes taking place with diesel, that it’s getting better, that people are noticing the cleaner equipment out on the roads.”

So how is that improved image helping fleets? One good example can be seen in California. As recently as 2005, the California Air Resources Board (CARB) was proposing a complete ban on diesel engines as the way to clean up the smog in the southern part of the state. Today those regulators are embracing “clean diesel” as an important element in their efforts to reduce emissions while also cutting greenhouse gas creation through better fuel efficiency.

Rounds of applause

Just last November, in a Washington, D.C., event celebrating the achievements of clean diesel, Nancy Sutley, chair of the Council on Environmental Quality and top environmental advisor to President Obama, said: “The diesel industry has succeeded in innovative efforts to improve fuel efficiency and dramatically reduce emissions. This continued commitment and progress is helping companies and communities save money and reduce pollution and propelling the clean energy jobs and industries that will power our economy in the 21st century.”

And then this April, CARB—the regulator that once wanted to ban diesel-powered trucks –released a video lauding the benefits of clean diesel ( Taped at a public display of new diesel emissions technologies, the video featured CARB executive officer James Goldstene praising the industry as having “responded admirably with a range of technologies that deliver clean diesel engines.” Turning a powerful adversary into an ally may be a soft emissions dividend, but it’s also clearly a valuable one helping to keep trucking efficient and viable in some of its most important markets.

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