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Clearing the Air: 2010 Diesel Emissions Standards

Originally Published in MotorHome Magazine

New 2010 diesel emissions standards, going into effect in January, will drive motorhome emissions to near zero. In some instances, the exhaust coming from the new diesel units may be almost cleaner than the air they take in.

But the benefit is not without its costs. Class A diesel retail chassis prices, for example, will increase by about $10,000 to $15,000, depending on the model. And, depending on the after-treatment technology, customers will also have to get used to periodically filling a new diesel exhaust fluid tank, in addition to their regular fuel tank.

Overall, engine/chassis manufacturers have taken two divergent approaches to meeting the 2010 U.S. Environmental Protection Agency (EPA) and California Air Resources Board (CARB) standards for on-highway diesel engines.

Diesel chassis/engine manufacturers, with the exception of Navistar and its Workhorse Custom Chassis and Monaco Coach affiliates, have opted to use Selective Catalytic Reduction (SCR) technology, with its significant after-treatment equipment, to meet the standards. That includes Freightliner Custom Chassis Corp., Cummins Engine and Spartan Chassis. SCR treats NOx emissions with a non-hazardous diesel exhaust fluid (DEF) – a chemical called urea – to reduce the NOx into nitrogen and water as it passes through the after-treatment catalyst system.

Navistar, in what it calls a less “customer-dependent” solution, is opting to use so-called Advanced EGR (exhaust gas recirculation) technology to meet the standards. Officials cite “proven” technologies such as advanced fuel injection, air management, electronic controls and proprietary combustion technology.

SCR benefits and Costs
SCR is a readily available, proven technology, already in wide use in European diesel engine cars and more than 200,000 European trucks. It’s also had 25 million miles of testing in North America, according to Martin Daum, president and CEO, Daimler Trucks North America. That made it more attractive than trying to create a new system for the U.S.

The technology also enables more power, better economy and reduced maintenance on the Freightliner Class A chassis, for example. Freightliner will offer the Cummins 8.3-l ISC, 6.7-l ISB, 8.9-l ISL, 11.9- and 15-l ISX engines in its Class A chassis in 2010. The ISB chassis will get more peak horsepower in a new 200 to 360-hp range; the ISC, a higher 330 to 380-hp range; and the ISL will offer a 370 to 450-hp range, according to Jonathan Randall, Freightliner Custom Chassis sales and marketing director. Economy improvements range up to 5 percent; and, because the engines burn cleaner, they’ll require fewer oil changes, reducing maintenance costs.

Sprinter vans also get a new peak 185-hp rating, 30-hp more than currently, and 325 lb-ft of torque, 45 lb-ft more, with their 3.0-l V-6. Fuel economy remains the same, though with the increased torque, customers could order a lower axle ratio to increase on-highway economy. Recommended oil change intervals continue to be 10,000 miles for at least the first year, though the company does plan to lengthen them at a future time, said Walther Bloch, Sprinter engineering support manager for the U.S. and Canada.

Given that a diesel-pusher like an ISB-equipped coach normally retails for about $175,000 to $225,000 and ISC models for about $225,000 to $250,000, company officials don’t think the price increases will have much of an impact on sales.

Randall said, “Diesels still outpace gas models from an aspiration standpoint. And that won’t change going forward.”

Sprinter uses the same principle for reducing emissions – for example, the urea tank – but its emissions system is different than that of the Class A’s. Daimler hasn’t yet finalized 2010 pricing on Sprinters, but increases are not expected to be anywhere near those of the larger Class A’s.

In today’s environment, costs have obviously become a more sensitive issue. Gulf Stream, for example, plans to drop its Sprinter diesel-based models. “I think it’s overpriced now,” said Claude Donati, vice president of its Motorized Division. “The category is not as strong as when we introduced it.”

Airstream, on the other hand, which produces the Sprinter-based Interstate model, still sees it playing a role in its overall “B-van” strategy. Although Class B motorhomes are a niche market, “It’s one we have a lot of confidence will grow more strongly than other segments,” said Bob Wheeler, company president. But, still, he noted, “If the gap between diesel and gas widens, it will drive more people to buy gas-powered Class B vans.”

There are currently 15 RV manufacturers that build or have applied to build on the Sprinter, according to Bloch. Along with Class B and C models, Winnebago also offers a Sprinter-based Class A, introduced earlier this year.

Gulf Stream will continue producing Class A Freightliner models – the Tour Master, Caribbean and Crescendo – as well as a Navistar chassis-based Class C Super Nova diesel. It sells more of the diesel Class C cutaway chassis models than the Class A’s, according to Donati.

He thinks the emissions changes and costs associated with them “will no doubt put the diesel category a little further out of reach of a lot of RVers. Ultimately, customers will get used to that. The category will remain viable. But, I do believe in tough times people are thinking smaller, less costly, more fuel-efficient.

“The full-time RVers will still want a diesel. If you’re a believer, there are a lot of reasons to go up to that price point. But people driving a Class C and looking at a diesel-pusher are most likely going to think harder or wait a little to save up, due to price increase, the economic conditions and the political climate of making a smaller carbon footprint. It’s not a good time for a $10,000 hit,” Donati concluded, noting it comes on top of a previous big emissions-related price hike a few years ago.

At that time, motorhome manufacturers “pre-bought” a lot of chassis to avoid the price increases and complexities of the then-new systems. But this year, officials such as Donati and Jayco’s Sid Johnson, director of marketing, don’t anticipate much “pre-buying,” even with the low level of Class A diesel inventories, given market conditions and manufacturer concerns about maintaining good cash flow.

The newly required diesel exhaust fluid poses additional customer expense. The per-gallon cost of this fluid isn’t available yet, according to Bloch. But owners will be able to fill up with DEF at truck stops and also buy two-gallon jugs carried at various service centers, like Freightliner, Caterpillar, Cummins and Detroit Diesels.

Based on the load being put on the engine, fuel quality and other variables, the advanced electronic engine controls will regulate the percentage of DEF injected into the after-treatment system, according to Scott Larson, Freightliner Custom Chassis senior manager of engineering. Freightliner officials estimate that the Class A diesels will consume, on average, one tank-full of DEF for every three tanks of diesel fuel.

The Sprinter tank, with 7.4 gallons of capacity, is large enough to allow drivers to go about 11,000 to 12,000 miles between DEF fill-ups. It was designed that way because, “in the beginning, we feel DEF is not going to be available everywhere. The tank’s size will allow drivers to continue operating until they take the vehicle in for service,” said Bloch. “Once DEF is readily available, we could diminish the size of the tank.”

Drivers will get three levels of warning for maintaining the fluid. First, they get an alert that they need to add fluid. If they ignore that, the next warning tells them they have so many miles to go and about 20 engine starts. If they continue to ignore that, on the 21st attempt, the motorhome will not start.

“We have to ensure by law that nobody can run the (DEF) tank dry because then the motorhome is out of compliance emissions-wise,” said Bloch. “It’s no different than maintaining your regular diesel fuel. If you ignore your diesel gauge, sooner or later the motorhome will also stop running.” Once a customer refills the DEF, the motorhome will start immediately.

The size of the new urea fluid tank/ emissions-related hardware being added to the underbody will also require varying degrees of modification by motorhome manufacturers. It’s not likely to have much impact on the large Class A chassis, but will require a fair degree of creative reconfiguring by Sprinter motorhome builders.

Said Freightliner’s Randall, “There’s more complexity on the (Class A) chassis, but it’s all packaged within the same dimensions as today. The chassis hasn’t gotten any bigger or smaller. We’re working closely with manufacturers to make room for the extra technology.”

Airstream’s Wheeler thinks that, for motorhome manufacturers building on the Sprinter, “It’s going to cause heartaches. It’s a tight vehicle from a packaging standpoint. To make an RV you have to use every square inch. And we’ll have to work around this sizable tank being added to the underbody.”

Said Bloch, “It’s a big tank. They will have to look carefully when they package the vehicle and also look carefully at the weight. They can’t relocate or modify the tank in any way.” Sprinters less than 10,000 pounds have an unloaded vehicle weight limit of 7,400 pounds. With the SCR adding 144 pounds to the Sprinter van curb weight, it will lose about 144 pounds of payload, reducing that much worth of body/equipment that can be added to it. The curb weight for the Sprinter chassis with a 11,030-pound gvwr will increase by 155 pounds, basically reducing its payload by that amount.

“So far,” Bloch added, “the response we’re getting is positive. The motorhome people know the emissions need to be met. And we do have an event where the upfitters will be able to see the vehicles live and check out the tank size and filler neck.”

Navistar System

Navistar is still in the final stages of testing and validating its MaxxForce engines to the new 2010 requirements. Because of that, key details of its 2010 program, such as pricing and power ratings, are yet to be announced.

As Ramin Younessi, the company’s group vice president of product development and business strategy, said, “As with any new engine program, up until the day we build that first truck, we will continue to fine-tune our engines, make necessary adjustments, test and validate to ensure our customers have the performance and reliability they expect.”

Even though price increases to cover its 2010 emissions equipment for Class A diesel chassis aren’t yet available, the company has provided some preview of them with the $6,000 increase it announced on its on-highway commercial and school buses.

“While our engines will not have the addition of extra after-treatment equipment like competitors choosing SCR, we’ve invested heavily into the development of a non-urea solution and meeting the stricter emissions levels carries a price,” said John McKinney, president of the company’s IC Bus subsidiary.

Company officials have been making a big issue of the fact that their engines won’t require any extra customer effort, like filling a urea tank. As McKinney noted, “We strongly believe the accountability for emissions compliance should rest on the manufacturer, not the action of the driver or service technician, the reliability of new technologies or the impact of harsh weather conditions.”

Still, heavy reliance on an EGR system typically also has its drawbacks. It is apt to put more heat on an engine, and reduce horsepower, requiring a larger displacement engine to compensate, for example. How Navistar deals with these issues remains to be seen.

But, clearly, motorhome manufacturers and buyers will have a choice of two very different motorhome emissions systems, beginning in 2010.

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