There appears to be little doubt that the vast majority of over-the-road bus and truck engine manufacturers plan to use selective catalyst reduction to meet the 2010 federal emission standards -- the most stringent round of exhaust controls yet.
 A consultant who specializes in designing and developing urea dispensing systems told a leading Wall Street investment firm, Bear Stearns, that there is now a"general consensus" among heavy vehicle OEMs that selective catalyst reduction will likely be the most practical technology for reaching the U.S. EPA-mandated 2010 NOx-reduction standards.
 The selective catalyst reduction system -- which injects a nitrogen containing agent like urea into the exhaust upstream of the catalyst to further eliminate NOx emissions -- is the technology thats being used in Europe for meeting emission standards there.
 However, to maintain the efficiency of the system's required NOx adsorbers, the urea needs to be periodically replenished.
 With just over two years to go before the standard kicks in, there still isn't a viable urea infrastructure in place in North America to serve commercial vehicles.
 To build a urea supply network, OEMs reportedly are starting to educate not only their customers but also truck stops, private fleets and dealers about what will be needed with respect to urea availability and storage.
 Earlier this year, the U.S. Environmental Protection Agency issued guidance on selective catalyst reduction to engine makers and OEMs regarding urea availability and what it expects the industry to do to prevent drivers from operating trucks and buses with depleted urea tanks.
 While headway reportedly is being made on that front, the future price of urea also could be a concern. Strong demand for fertilizer and animal feed (which are components of urea) in the agricultural market could keep supply somewhat scarce for the transportation sector in some regions.
 As a result, Bear Sterns' industry source speculated that some OEMs may reconsider using NOx adsorbers to meet 2010 emissions standard if urea prices continue to climb.