That seems to be the big question today as engine makers focus on the 2010 emission standards: do you incorporate selective catalytic reduction (SCR) into your emission solution ... or not?
International Truck & Engine Corp. joined Cummins Engine Co. in the 'No SCR' catergory today, announcing that it won't use SCR at least for its highway products. Cummins said Sept. 24 that it would use SCR only for its medium-duty engines, not its big bore units. Meanwhile,
Paccar's MX line uses SCR to meet European truck emission regulations, as do Volvo and DDC's products, so it's a no-brainer to do the same in the U.S. as all three build "global engine platforms" designed to be tweaked only slightly for the specific regions of world they are sold in. For example, DDC -- which unveiled its new DD15 in mid-October -- said only 10% of the components in its new global engine platform change from market to market; the rest remains the same.
What's the hang up with SCR? Basically, it's an emissions after-treatment technology that relies on injecting urea -- an amonia compound -- into the exhaust stream to reduce NOx emissions. Not only does such a system require its own complex array of sensors and electronic controls, it needs a tank or urea solution on board that must be refilled as the truck travels down the highway. Dan Ustian, chairman, president nand CEO of
Also, while International found SCR to be a way to effectively meet 2010 emissions standards, it adds to the cost and complexity of use of commercial vehicles for truck and bus fleet operators. I've heard that "extra cost" could be another $10,000 above what truckers are paying for 2007-compliant engines, but I caution that this is only an estimate. Urea itself is a cheap chemical compound and requires no special storage -- a simple plastic tank will do. Even if it freezes, it's still good -- once it thaws and becomes liquid again, it's ready for use. And DDC and Volvo both believe using SCR can help boost fuel economy, recovering MPG lost to the technology demands of 2007.
The upshot is that 2010 is already looking very different that 2007, as the engine makers are going to be offering different emission compliance solutions -- something that didn't happen this year. How that affects trucking's bottom line, however, remains to be seen.