Quote:
Originally Posted by Old Mechanic
By weighed overall they should have considered the ultra low C02 emissions against the slightly over reg NOX emissions.
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The longer I work with this stuff, the less judgmental I have become. Often, when I run into something seemingly stupid in the regs I ultimately end up tracing it back to a compromise demanded by the automakers themselves.
The problem with NOx is that the curve is pretty steep. Something only has to be a little out of whack for NOx to soar. And, a lot of times those cases are coupled with a lot more soot, the sorts of carbon that cats don't readily clean. There are some good ways of dealing with both these issues, but there is still a problem with cost effective (and reliable) monitoring systems.
That's why we have active projects in both those areas. The thinking here is that there is no single magic bullet, so we should be facilitating multiple areas of 'incremental improvement' in emissions/fuel efficiency. Though, frankly, I'd just like cheap and effective NOx sensing so that I could get rid of the noisy canary in my office (sorry, inside joke, I'm the lab gas nazi here, and get tormented for it).
-jjf