'07 means adjustments

READY OR NOT, here they come.

On Jan. 1, 2007, the new emissions policy comes into effect. Are the major manufacturers ready? They're getting there.

The Work Truck Show got off to a hard-hitting start with a Bonus Session that detailed the adjustments that are being made to meet the 2007 emissions policy. The panel featured Greg Saele, International Truck and Engine's engine marketing manager, Landon Grogan, Freightliner's engineering project manager, Bill Reed, Ford's manager of special vehicle engineering, and Steve Matsil, GMC's vehicle chief engineer.

“There's a lot that's still under development,” Reed said. “There's a lot of work going on at Ford, and probably all of the manufacturers.”

The Environmental Protection Agency (EPA) is mandating a 50% reduction in the NOx (nitrogen oxides) standard and a 90% reduction in the PM (particulate matter) standard.

The NOx standard has been revised to 0.20 g/bhp-hr (grams per brake horsepower hour), to be phased in for diesel engines between 2007 and 2010. (The phase-in would be on a percent-of-sales basis: 50% from 2007 to 2009 and 100% in 2010.)

The PM standard has been revised to 0.01 g/bhp-hr, to take full effect in the 2007 heavy-duty engine model year.

In addition, the certification test fuel sulfur content maximum has been reduced to 15 ppm (parts per million). The diesel fuel regulation limits the sulfur content in on-highway diesel fuel to 15 ppm, down from the previous 500 ppm. Refiners will be required to start producing the 15 ppm fuel beginning June 1, 2006.

The EPA estimates the cost of reducing the sulfur content will result in an increase of up to five cents per gallon in the price of fuel, and that the new emission standard will cause an increase of $1,200 to $1,900 in the cost of vehicles.

EPA's assessment

The EPA started regulating the gaseous emissions from the heavy-duty highway uses of diesel engines in the 1970s and particles in the 1980s.

The EPA's health assessment concludes that long-term (ie, chronic) exposure to diesel exhaust is likely to pose a lung-cancer hazard, as well as damage the lung in other ways, depending on exposure. The health assessment's conclusions are based on exposure to exhaust from diesel engines built prior to the mid-1990s. The assessment also states that evidence is emerging that diesel exhaust exacerbates existing allergies and asthma symptoms, and recognizes that diesel-engine exhaust emissions, as a mixture of many constituents, also contribute to ambient concentrations of several criteria air pollutants, including nitrogen oxides, sulfur oxides, fine particles, and other hazardous air pollutants.

According to the EPA, the amount of exhaust particulate from on-road engines is expected to decrease 90% from today's levels with the engines designed to meet the 2007 regulations, and the composition of the exhaust particulate matter and the gases also will change.

The emissions standards, signed by the EPA on December 21, 2000, mean major changes for engine makers, which have to incorporate aftertreatment devices such as particulate traps (which collect and burn away particulate emissions) and catalytic converters (which convert damaging pollutants to less-harmful products).

And they mean changes for OEMs and bodybuilders, too.

“Our goals are to do this with improved performance, minimal impact to fuel economy and service, and by delivering customer value through superior vehicle engineering,” Saele said. “It's not just the engines that are changing. It really requires a system of approach, with changes to the engine and fuel. Aftertreatment is added, and lube oil has to change.”

He said all of the engines are taking an evolutionary approach for '07. Most of the International Cummins engine changes are to control NOx, and are using the same systems used today, but with improved Exhaust Gas Recirculation (EGR) — an emissions control technique for reducing oxides of nitrogen emissions in the tailpipe, with a small amount of exhaust gas recirculated back into the intake manifold to dilute the incoming air/fuel mixture — and more capacity.

Talking about the fuel changes, he said, “By taking the sulfur out of the fuel, you automatically reduce the particulate matter (PM), and that will help old engines as well. At the same time, sulfur in the fuel will poison the catalysts that are in the fancy aftertreatments we're all adding. So this new fuel is an enabler for the new exhaust systems. The sulfur they're taking out actually has quite a bit of energy value, so there will be a 1-3% loss in fuel economy.

“CJ4, the new engine oil, with only 1% sulfate ash allowed. There are limits on sulfur and phosphorous as well. The main reason is that the chemicals, when they get past the rings, ultimately end up in the Diesel Particulate Filter (DPF), and can't be burned out the way the soot is. They just collect in there over time. So that's where the maintenance of this filter comes from. Every 150,000 miles or greater, you have to clean out the contaminants. This new oil is being designed to limits its impact. You need improved hardware change to support this.

“The exhaust filters are like a ceramic filter. The exhaust gas has to flow through the filter walls. The soot collects in there fairly rapidly and then when the exhaust is hot enough, it burns itself out. It's like you're collecting little bits of charcoal in there. It won't burn off just by throwing a match on it. It has to get pretty hot to be lit and burned off.”

He described the regenerative strategies:

In-cylinder dosing.

“You do a late post-injection with the vehicle's fuel system that's in the cylinder and then you flow the extra fuel system through the exhaust port and into the exhaust system. The benefit is that you have no extra fuel lines and fuel injections in the exhaust system, so there are no extra parts to be in the way or break.”

Downstream dosing.

“Same thing, except there's a fuel injector in the tailpipe after the turbocharger. Cat is using a system similar to downstream dosing where you have a fuel injector in the tailpipe but it's also supplying its own air and a spark to burn it.”

Talking about cooling systems, he said the big change on medium-duty trucks is that to accommodate a larger radiator, there will be a bracket on the right side of the frame rail instead of having the frame go all the way to the front of the vehicle.

“On the 7000 series trucks, where we always had the radiator above the frame rail, that still will be the case,” he said. “You will still be able to get the front-engine PTO and integral frame rail extensions that will be straight rails, not S-shaped. There's no change in functionality, though it will have a larger hood.”

Saele said there will be no change to the cab height and no change in the hood for the 4000 series.

He said gas temperatures in the DPF can reach 1100 to 1300 degrees F during regeneration. Mufflers will be insulated to maintain the same touch temperatures as with the pre-'07 engines.

“We're working on heat-dissipation devices to reduce tailpipe exhaust temperatures for some applications,” he said. “We don't expect the touch temperatures of any of these parts to be much hotter than they are today.”

He said almost all exhaust-configuration options will be available, including right side, left side, horizontal and vertical.

“Dual vertical verticals on heavy trucks will no longer be available because you'd need two PFs and you'd have to balance the flow, which would be a great expense,” he said. “We still have available dual stacks with a horizontal muffler.”

He said International will be using stainless exhaust systems.

“These filters are very expensive,” he said. “For plow trucks, where there's a lot of corrosion, you don't want to have to replace $2,000 exhaust filter just because it rotted away because of a high-salt environment.

“You won't be able to cut into the exhaust pipe from the turbine to the DPF. After the filter, you'll still be able to cut into the exhaust to add dump bodies subject to maximum back-pressure requirements.”

Talking about the EPA's minimum interval for DPF maintenance (ash cleaning), Grogan said the initial service interval will be 100,000 miles. Then it will be 150,000 miles or 4500 hours.

“The EPA also has indicated to us that they will make allowances for some specific vocations to have frequent service intervals,” he said. “The impact is that we can have, in some cases, smaller DPFs that could lead to better packaging.”

He said the useful-life requirements are 185,000 miles for Class 7 and 435,000 for Class 8.

In terms of aftertreatment functionality, he said that on the passive or automatic systems, the typical temperatures above 500 degrees F provide that capability.

“It is transparent to the operator,” he said. “The active regeneration does require higher temperatures and the introduction of fuel.

“How will the driver know that regeneration is required? Depending on the operation of the vehicle, he might not. It might be an automatic event. In more severe cases where you're not achieving the automatic situation, a DPF lamp comes on. In some cases, he might have to stop the vehicle and initiate the regeneration sequence with a button. In these high-temperature conditions, you also have additional high-exhaust gas temperature lamp.

“Higher EGR rates increase the heat load of engines. The under-hood temperature is higher due to radiated heat. It requires more careful selection of materials.

“The addition of the DPF increases exhaust-gas temperatures during active regeneration. For us, that meant a different material in the exhaust system, going to stainless steel and more insulation to protect from higher heat in some cases, but also to promote passive regeneration to keep the temperature in the exhaust pipe down to the aftertreatment device. These are all larger-mass systems up to three times the weight of a muffler, so the support systems for these devices are different.”

He said that in Freightliner and Sterling models, the cooling module is 20% larger.

“To accommodate that, without having to raise the cab or change the hoods, we're putting rails at the end with bolt-on extensions, or we're doing straight rails,” he said.

“The sizes we're seeing are fairly consistent with mufflers, or slightly larger. The bigger significance is the weight and the fact that you have other features or devices that you don't have on mufflers — Delta P sensors and harnesses, for example.”

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