Another Diesel Dilemma?

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The 2002 engine pre-buy forced equipment manufacturers into a “cliff” event they’re loath to repeat. They were forced to run their plants around the clock to meet motor carriers’ accelerated buying plans to beat the new emissions deadline and then had to lay off many of the workers once the deadline passed and demand dropped – a costly way to operate a manufacturing facility.

So equipment manufacturers must have shuddered when they heard Steve Duley’s admission during a recent engine summit held by the Technology and Maintenance Council of the American Trucking Associations. “We are planning a pre-buy,” said Schneider National’s vice-president of purchasing, referring to plans to stock up on pumpkin-colored trucks before tighter emissions standards are introduced in 2007. The truckload giant is even looking at whether it can add two years to its traditional trade-in cycle, further delaying the purchase of the next generation of technology.

Engines built to meet the latest emission standards already cost about US$5,000 more than their predecessors, and fuel efficiency dropped by three to five per cent, he said, balking at suggestions that it was a minor loss. “It took us 10 years to get that three to five per cent, and we lost it in one move.”

It won’t be the last addition to the fleet’s operating and maintenance budgets. He’s expecting all-new repair costs to emerge once the latest equipment ages beyond warranty coverage.

The fleet also expects to spend an extra US$25,000 during the life of each truck built to 2007 standards, thanks to the cost of related equipment, its thirst for fuel, additional maintenance requirements, and higher fuel prices expected to accompany the rollout of Ultra-Low Sulfur Diesel (ULSD).

The question of whether fleets will try to delay purchases of the new equipment has even led to a feud between two branches of the U.S. government.

The U.S. General Accounting Office (GAO) has criticized the U.S. Environmental Protection Agency’s (EPA) hastened October 2002 rollout of existing guidelines, which was a penalty for “defeat devices” that allowed engines to emit higher levels of NOx in the name of on-highway fuel efficiency.

The EPA underestimated the cost to the trucking industry, and the resulting “pre-buy” of older engine designs meant that many fleets didn’t buy the cleaner equipment as soon as expected, the report concluded. And cleaner air isn’t realized until new equipment is put on the road.

Now the GAO is calling for an independent review of plans to meet 2007 guidelines, and is promoting the idea of financial incentives to encourage fleets to embrace the cleaner equipment.

Between 20% and 26% of the trucks built in the six months before the October 2002 deadline were linked to fleets scrambling to buy older technology, the GAO found. And the boom-bust business cycle hammered the trucking industry. Equipment buyers faced unexpected costs when they accelerated plans to purchase equipment and engine makers were forced into decisions that wreaked havoc on their manufacturing strategy.

For that matter, the shift favored engine manufacturers that didn’t meet the tightened standards, the GAO said. The Mercedes Benz MBE 4000, which was marketed by Daimler Chrysler cousin Detroit Diesel, wasn’t covered under related 1998 court orders. Caterpillar opted to pay a penalty allowed under the Clean Air Act because its “bridge” engines didn’t meet the 2004 standards. But both companies gained a bigger share of the engine market in the process.

“This 2007 rule is a big deal,” admitted EPA assistant administrator Jeffrey Holmstead, likening the shift to the introduction of catalytic converters and unleaded gasoline for cars. “We know it’s a big deal for your industry. We know it’s a big deal for the engine manufacturers. We know it’s a big deal for the fuel suppliers as well.”

While the next round of equipment is expected to add another US $3,000 to the cost of a truck, “we think it’s a cost from a societal perspective that is worth bearing,” he said.

The resulting drop in pollutants will prevent 8,300 deaths, 360,000 asthma attacks and 1.5 million lost worker days every year, added Bill Becker, the executive director of a group representing state and local environmental agencies.

The first 2007-compliant engines are expected to be available for fleet tests as early as next year. And the related supply of ULSD is also expected to be expanded with a “clean corridors” initiative that will ensure the required fuel is available along major trucking routes during the same timeframe.


Early problems with the engines built to 2004 standards haven’t been limited to lost fuel economy and shortened oil drain intervals, although most emission-related equipment failures appear to have been addressed.

“If there is a sensor on the engine, it failed at some time,” said Dennis Beal, vice-president of physical assets at FedEx Freight, which saw fuel economy drop by as much as 15%. “We had no real horror stories,” he admitted, “but we had a lot of pain, and the costs have been extraordinary.”

Other fleets have reported emission-related equipment failures ranging from Exhaust Gas Recirculation (EGR) valves to injectors.

Coolants may have become another casualty, with ph levels dropping “faster and lower than we have ever seen,” said Amalgamated Laboratories president Ed Eaton, noting that the fluids are quicker to turn acidic in 2004-compliant engines.

While Supplemental Coolant Additives (SCAs) can protect against engine deposits, corrosion and liner pitting, they aren’t effective in coolants below a ph of 8.0 – and such numbers are “not uncommon” in the EGR engines, he said.

Cooling packages on engines designed to meet the 2004 standards also tend to require draining within 100,000 to 150,000 miles (160,000 to 240,000 km), he added. An increase in sulfates has lowered the available protection for copper and brass in radiators. And for some unknown reason, there also appears to be a need for more frequent top-ups.


The 2007-compliant equipment will be heavier than existing trucks, thanks to the addition of everything from filters to trap exhaust particles, to the larger radiators and additional coolant needed to handle the higher heats associated with accelerated EGR rates, said Jim Salas, director of maintenance and field support services for Ryder Transportation Services.

Caterpillar uses its ACERT technology rather than EGR when controlling NOx, but it still plans to use the filters.

The filters themselves are “big, heavy pieces,” said Engelhard Corp.’s Glen Blythe, suggesting that they’ll be15 inches (38 centimeters) long and just as wide, weighing about 5 lb. (a little over 2 kilograms). The platinum in them will also add to the expense.

“It’s not going to be out of the question to see $1,000 of precious metals,” he said. And a simple mistake such as using diesel with current sulfur levels could destroy it, some have claimed.

Luckily, much of the equipment used to meet 2007 standards is based on proven technology. The particulate filters are already found on school buses, said Patrick Charbonneau, International’s vice-president of regulatory and technology affairs.

And while the higher heats associated with accelerated EGR will likely require larger radiators and charge air coolers, the new equipment will fit “within existing hood outlines,” said Detroit Diesel’s Tim Tindall. Some aerodynamic truck shapes had to be re-worked to make room for the additional equipment and larger cooling packages associated with 2004-compliant engines.


The new standards will also require new engine fluids.

The lower sulfur levels in ULSD will reduce the creation of sulfuric acid during the combustion process, possibly reducing bearing corrosion and liner wear. But the related drop in lubricity means less protection for fuel injection pumps. Additives such as those already being used in California will need to be introduced to counter the change, said Jim McGeehan, ChevronTexaco’s global manager of diesel engine technology.

Some refining processes could also change the cetane numbers that ensure cold starts and control white smoke, said Ken Kimura, a principal engineer at BP. Still, changes in cold flow properties could simply require the addition of kerosene in cold climes.

While 80% of on-road diesel has to meet the 15ppm sulfur limits by 2006, about 90% of available diesel is expected to meet the standard by that time.

Meanwhile, the levels of ash in PC10 oils being designed for the 2007 engines will need to drop from 1.5% to 1.0% to protect the particulate filters, but those levels are still expected to be high enough to neutralize the acids in EGR engines.


Most of the time, contaminants collected in the new particulate filters are expected to be burned away by exhaust that exceeds 550 to 600 Celsius on the open highway, although that will be a particular challenge for pick-up and delivery systems that don’t typically see the higher exhaust temperatures.

“There are various methods to burn diesel particulate – electrical heat, heat from fuel combustion, catalytic fuel additives,” Engelhard’s Glen Blythe said of the “active” regeneration components that will take care of contaminants the rest of the time.

Truck makers will also face challenges in finding homes for the new equipment, since exhaust will cool by 50 F (10 C) for every foot that it passes through an exhaust pipe.

But the filters do have to be cleared since a clogged design will increase back pressure in the exhaust, leading to lost fuel economy. And while the new filters are expected to last more than 240,000 km, they’ll eventually require maintenance.

Speakers at the TMC conference suggested that maintenance will take about two hours, and involve blowing contaminants into a Hepa filter. “Ash is very, very fine and it will fly all over the shop,” Blythe warned of the need for something to catch it.

But there is an irony here. While the filters are designed to keep the contaminants out of the air, there aren’t any standards for ensuring that the ash isn’t simply blown back into the wind.


Despite public comments from engine makers, industry analyst Martin Labbe questions the reports that insist engine makers will be ready.

“The EPA shows up at your door and says, ‘How are things going?’ what are you going to say?” he asked, suggesting that manufacturers may be painting an overly optimistic picture to avoid increased scrutiny.

Regardless of the struggles to meet these standards – and still-tighter levels to come in 2010 – the entire process may mark a light at the end of the tunnel in the battle to lower emissions.

“We’re not planning any further diesel engine standards in the near future,” the EPA’s Holmstead said. “This technology is amazing. We’re actually having to re-outfit our laboratories so we can even measure the levels of emissions … We can’t imagine another round of standards for this industry.”

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