The US Environmental Protection Agency is demanding the trucking industry reduce its emissions by 90% in 2007. It's no small feat, and in order to comply, manufacturers will have to introduce new comp...
The US Environmental Protection Agency is demanding the trucking industry reduce its emissions by 90% in 2007. It’s no small feat, and in order to comply, manufacturers will have to introduce new components as well as a costly aftertreatment system. Between now and December, Truck News will be exploring, in detail, each element of the 2007 emissions equation. We continue the series this month with Part 4 – a look at engines.
TORONTO, Ont. – The centerpiece of the 2007 EPA emissions equation is the engine itself. And it was the engine that posed manufacturers with the biggest challenge the last time around, when they had to meet the 2002 emissions standards.
Fuel economy dropped an average of 3-5% with some owners complaining of double-digit losses. Meanwhile, the trucks cost substantially more to begin with.
It was the first time the trucking industry was forced to shell out more money for an inferior product in terms of cost of operation. Most manufacturers now admit they were ill-prepared for EPA 02.
This time around, however, the manufacturers each claim to be more prepared than in 2002, since they are building on their existing platforms (ACERT for Caterpillar and cooled EGR for the rest).
But that’s not to say these engines won’t cost more than today’s.
Trucks with 2007 engines under the hood (in most cases these will be 2008 model year tractors) will cost between $7,500 and $10,000 more than today’s vehicles. The premium is non-negotiable and in most cases, slapped onto the price of new vehicles as a surcharge. It can be attributed to not only the engine itself, but also the diesel particulate filter and the cost of redesigning the chassis to accommodate the new engine and increased cooling capacity it necessitates.
The good news is that field tests are showing the engines are in most cases maintaining their current fuel economy.
“In 2002 there was a very noticeable change in fuel economy,” admits Tim Tindall, director of Detroit Diesel’s EPA 07 engine program. “Today, it’s a very, very small difference. Some people say it’s better and some people say it’s a little bit worse but it’s something you’re going to really have to look for (to notice).”
Detroit Diesel has run plenty of miles on its new engines to validate those claims. By the end of 2006 it will have accumulated 14 million miles on its Series 60 and 24 million miles including its Mercedes-Benz powerplants. That’s the equivalent of 50 runs to the moon and back and to say it’s an improvement over 2002 would be an understatement. In 2002, the company admits to having only run 2.8 million test miles – 2.3 million of which were on a dynamometer. At press time, Detroit Diesel had 36 trucks in customer hands running real-world miles in various applications.
Dr. Steve Charlton, head of the 2007 engine program for Cummins, says field testing has progressed much more smoothly this time around, thanks largely to improved testing capabilities made possible through new technology.
“We have data acquisition and telematics on all field test vehicles, so within a two-hour cycle we get the data from the trucks flowing back into the tech center,” Charlton explains. “If any fault codes are triggered on any vehicles in the morning, by lunchtime the engine has a listing and even if the driver is unaware of anything going on, we will actually know. That has been a tremendous tool for finding information early and being able to fix them and that’s a first for 2007.”
All engine manufacturers have reported smooth sailing in field testing.
“The only big surprise is, in fact, that there have been no surprises,” says David McKenna, product marketing manager for engines, transmissions and axles with Mack Trucks. Mack claims to be achieving improved fuel mileage over its current engines thanks to two completely new engine platforms.
As in 2002, manufacturers have chosen one of two paths to meet the EPA’s stringent emissions standards. Mack, Volvo, Detroit Diesel and Cummins have opted for cooled exhaust gas recirculation (EGR). EGR returns a small amount of exhaust to the cylinders to lower combustion temperatures and reduce emissions. The principle change in 2007 is that the amount of exhaust being routed back to the cylinders has increased.
Caterpillar continues to forge ahead with its own ACERT (Advanced Combustion Emissions Reduction Technology) platform. It’s a systems solution that combines an oxidation catalyst with series turbochargers, variable valve control, a high pressure multiple injection fuel system and electronics control systems.
However, to meet the 2007 emissions standards, Cat is also introducing a process called Clean Gas Induction (CGI). CGI funnels clean exhaust through the combustion chamber. If it sounds a lot like EGR, that’s because it is – with one key difference. The exhaust gas re-routed through CGI is taken downstream of the particulate filter, so it has already been filtered and cleared of soot.
“Rather than re-introducing dirty, sooty exhaust back into the system, CGI simply uses more cool, clean air to reduce combustion temperatures and achieve the necessary reduction in NOx and particulate matter,” explains Greg Gauger, director of On-Highway Power Systems with Caterpillar.
“It’s soot-free and the exhaust pipes are as clean as when the trucks are new,” Michael Powers, product development manager with Caterpillar says of test trucks with 07 engines.
Powers says EGR uses sooty air which damages components, hinders performance and reduces engine life. His competitors say routing exhaust gas through the charge air cooler can result in contaminants entering the system.
The bottom line is that both technologies will meet the EPA emissions requirements. The choice is yours and will likely come down to brand preference, previous experience and of course, price.
Unlike in 2002, this round of EPA emissions standards will also control crankcase emissions. Cummins has added a coalescing filter to reduce crankcase emissions. It’s mounted on the side of the engine and the filter will need to be changed every 125,000-150,000 miles – depending on the engine.
Charlton says it takes about three minutes to change the filter and it can be replaced during regularly-scheduled oil changes.
Other engine manufacturers, such as Detroit Diesel, have opted for a maintenance-free equivalent.
“We have what’s called a centrifugal separator that performs the function of a coalescing filter by taking oil out of the crankcase and we return that oil to the oil pan,” Tindall says. “The fumes are vented into the atmosphere. That device is not a filter, it requires no maintenance. We elected that approach because it will impose no further maintenance on the user and it provides the same separating characteristics.”
Beyond that, it will take a keen eye to notice any further changes to the 2007 engines as a result of the latest emission requirements.
Cummins has added an electronic actuator to its variable geometry turbocharger that allows it to move more precisely and quickly. It has also relocated the EGR valve from the hot side of the engine to the cooler side.
“It now operates at 300-400 F which is a much friendlier environment,” Charlton points out.
Engine manufacturers have been emphasizing their readiness for 2007 all year long. Reports from the field suggest they’ve done their homework and the transition should be a smooth one. At a cost increase of $7,500-$10,000 per truck, one certainly hopes that’s the case.