In May, John Deere announced its PowerTech PVX and PSX 9.0 litre engines received certification for Interim Tier 4 and the European equivalent Stage IIIB emissions standards. Interim Tier 4 regulations will come into force in North America in January, 2011, for engines above 174 horsepower.
The PowerTech engines stick with cooled exhaust gas recirculation (CEGR) and variable geometry turbocharger (VGT) technology to meet the lower emissions levels. The standards require a 90 per cent reduction in particulate matter (PM) and a 50 per cent reduction in NOx (nitrogen oxide) over the current Tier 3 regulations.
The decision to stay with CEGR and VGT as long as possible shouldn’t come as any surprise; it’s a design the company has publicly favoured for some time. “We believe our chosen technology path provides the best value for Interim Tier 4,” said Doug Laudick, product planning manager for John Deere Power Systems (JDPS). The company originally introduced its CEGR and VGT engine design in 2005.
“The PowerTech PVX and PSX 9.0L engines have already gone through the customer equivalent of nearly 200,000 hours of testing. Field and lab testing continues to ensure the final product will meet the unique requirements expected from off-highway diesel engines,” added Laudick.
The new Interim Tier 4-compliant Deere engines began rolling off the assembly line last month, well ahead of the January deadline.
The company continues to shy away from selective catalytic reduction (SCR) in its engine designs, although several corporate spokesmen have admitted meeting the last step in emissions regulations, Final Tier 4, may not be possible without out it.
“For Interim Tier 4 we’re not only looking at fuel economy we’re taking into consideration total fluid consumption,” said Brian Brown, manager of worldwide marketing for JDPS. SCR requires the use of a urea-based fluid that is burned in the exhaust stream after combustion to reduce NOx and PM. That means an additional cost for operators.
However, companies that have already adopted SCR maintain the cost of the additional fluid is offset, at least in part, by the fuel efficiency it allows them to build into engines.
Engines 175 horsepower and above must in full compliance with final Tier 4 emissions standards by the end of 2014.
Scott Garvey is machinery editor for Grainews