If anyone is surprised that John Deere announced last Friday it would use an "Integrated Emissions Control" system that includes selective catalytic reduction (SCR) technology to meet air standards under the Final Tier 4 emissions regulations — they shouldn’t be. These standards call for dramatically reduced emissions of nitrous oxides (NOx) and particulate matter from off-road vehicles.

The first clue that Deere probably wouldn’t stick with its cooled EGR (exhaust gas recirculation) engines for the final regs came about a year and a half ago. At that time, Deere announced it was sticking with its cooled EGR technology to meet Interim Tier 4 emission standards. At the same time, the company said it was leaving all options open to other approaches to meet final standards that would take effect in 2014. The value proposition they pushed hard back then — that EGR was “The right technology. Right now” — seemed a bit half-hearted.

Deere’s biggest competitors had all announced they were committed to going with SCR back then for a variety of reasons. AGCO was first out of the box. Their reasoning was SCR had proven itself in on-highway engines and this technology allowed engines to do their job of delivering horsepower to the ground and a separate SCR system would take care of the emissions without affecting engine performance.

At a media event in June 2010 at its Engineering Center in Burr Ridge, Ill., Case IH said it favored the SCR approach because it offers farmers a significant advantage when it comes to fuel economy. The company said utilizing the technology with the interim engines would also allow them to move more easily into developing Final Tier 4 engines for 2014.

Engineers from Fiat Power Train (FPT), which developed and are building the new diesel engines for Case IH, said they also feared recirculating exhaust gases that contain soot and other contaminants back into the engine. This, they believe, could ultimately lead to engine problems for the operator.

Officially, this is what Deere’s March 2 press release said about their new engines. “To meet Final Tier 4/Stage IV emissions regulations in some power categories, John Deere developed the Integrated Emissions Control system — an optimized aftertreatment solution paired with the performance-enhanced, fuel-efficient Interim Tier 4/Stage III B engine platform, featuring proven cooled exhaust gas recirculation (EGR). The John Deere Integrated Emissions Control system will typically consist of a diesel oxidation catalyst (DOC), diesel particulate filter (DPF) and a selective catalytic reduction (SCR) system specifically designed to meet the rigorous demands of off-highway applications. John Deere will continue to tailor its Integrated Emissions Control system configurations to fit a variety of off-highway applications.”

At least initially, we know through our own surveys the EGR vs. SCR debate left some dealers and many farmers perplexed about the differing engine technologies. So it makes me wonder what Deere dealers are thinking now?

Did they tell their customers the Interim Tier 4 EGR technology was a better choice than the SCR engines their competitors were touting? How will they now explain the company’s decision to adopt the SCR concept when they made such a strong case against it for the past few years? What will adoption of the new technology mean in added costs for Deere customers who have already been through some pretty hefty price hikes?

I guess we’ll have to wait and see how it all shakes out, but I wouldn’t mind hearing what dealers are thinking about Deere’s apparent change in direction.