The latter engine doesn’t meet the 2010 EPA NOx standard presently, sitting at 0.5 grams instead of the 0.2 required, and there’s no public indication about when it will. But that’s perfectly legal in ...

Specifically, 2010 engines can emit no more than 0.2 grams of NOx, which has been phased in since the 2007 regs, and 0.01 grams of soot per brake-horsepower-hour, unchanged from ’07. And for the first ...