COLUMBUS, Ind. – Unprecedented fuel prices and the discovery of a new copper-zeolite catalyst material have driven Cummins to change directions on its path to EPA2010 heavy-duty engine compliance.

The company explained its mid-August decision to adopt urea-based Selective Catalytic Reduction (SCR) during a conference call with trade journalists. Steve Charlton, vice-president of heavy-duty engineering with Cummins, explained the discovery of copper-zeolite as an improved SCR catalyst material was the key enabler.

“Copper-zeolite is the key technology that’s allowed us to make this change,” he said, noting it has a far better NOx efficiency rate and is more durable in high temperatures than the iron-zeolite alternative that’s widely used today.

The copper-zeolite material will be coated onto the honeycomb ceramic substrate within the SCR catalyst, providing improved NOxreducing capabilities, Charlton explained. As a result, he said Cummins can now provide up to 5% better fuel mileage using SCR than it could with the in-cylinder solution it was previously pursuing.

Combine the improved efficiency offered by the copper-zeolite SCR catalyst material with record fuel prices, and Cummins felt it simply had to change course for its heavy-duty engine line. It was already developing SCR engines for its midrange products, which should make the transition easier.

“The business case for delivering industry-leading fuel economy performance from our products was too compelling for us to overlook, and therefore drove this decision,” said Ed Pence, vice-president and general manager of Cummins heavy-duty engine business. “We believe this decision demonstrates Cummins decisiveness to do what’s right, to offer the right technology and it demonstrates our agility, which we hold as a core value around here.”

Cummins decision to adopt SCR leaves Navistar as the only North American engine manufacturer that plans to meet EPA2010 emissions standards without exhaust after-treatment. Cummins officials insisted they could have met the 2010 requirements with their in-cylinder solution, had they chosen to continue pursuing it.

“That product was all set to launch in January, 2010,” said Charlton. “The program was performing well, the product was performing well and we were hitting all our targets.”

But current fuel prices have made fuel economy the top priority for customers, Cummins officials acknowledged, which made it necessary to change paths.

“The first thing (customers) want to talk about is how we can help them improve their operating cost, and primarily fuel economy,” Jeff Jones, vice-president of sales and marketing communications said. “Whether you’re a fleet or owner/operator, the value of a percentage or two fuel economy improvement is a big number.”

He pointed out that a truck consuming 20,000 gallons of diesel per year stands to save about $1,000 each year for every percentage that fuel economy can be improved.

Charlton said the work Cummins has done to date on its in-cylinder solution, has not been a wasted effort. Cummins 2010 engines with SCR will still use EGR, although smaller amounts of exhaust will be recirculated. This will result in less heat rejection, he explained.

The base engine will remain the same and Cummins will continue to offer a full range of horsepower ratings, he stressed.

However, plans to introduce a 16-litre ISX have been shelved, since Charlton said the company no longer needs the higher-displacement engine to meet all the horsepower ratings it intends to offer.

Charlton also pointed out that Cummins won’t be playing catch-up, since it has already been developing an SCR solution for its mid-range line, and has about 200,000 units with SCR already in use in other parts of the world. In fact, a division of the company – Cummins Emission Solutions – is already in the business of designing and building SCR systems.

Recently, Cummins inked a deal with Daimler Trucks North America which would provide customers with an alternative to SCR. However, company officials are not concerned they will lose ground due to their decision to change paths. Pence said Cummins will continue to differentiate itself based on quality and service, if not technology.

“Differentiation comes in a lot of different forms…it’s not necessarily defined by what technology you use versus what other people are using,” said Pence.

He noted that Cummins has gained market share in both the mid-range and heavy-duty market segments since the launch of EPA07 product line, despite the fact all manufacturers employ a similar architecture.

“Differentiation with the 07 product line was defined on the customer side by performance, reliability, durability and how we support our customers and OEM partners with our product,” he added.

When Cummins first rejected the idea of adopting SCR, it was partly due to concerns about the availability of urea.

However, Jones pointed out a truck will run at least 6,000 miles before its urea tank runs dry. Visible and audible warnings will give drivers plenty of notice, as per EPA requirements.

Cummins officials say they are already working with their OEM partners to ensure they are ready to roll by January, 2010. The company says it is already field-testing some engines with SCR and will be conducting cold-weather testing this winter.