New emissions standards in 2010 will make things too stringent for GM's Duramax diesel, in its current form, to make the grade. To help its prize student pass the looming tests, GM is investing $69 million in its DMAX plant (a joint venture diesel engine factory in Moraine, Ohio) for plant renovations and new machinery and tooling.

While GM doesn't really rate the uptake of diesel in the American market in passenger cars, the Duramax is an engine that has powered its fair share of GM sales. Since its introduction in 2001, more than one million Duramax diesels have found their way on the road in Chevy Silverados, GMC Sierras, full-size vans and some medium duty trucks. The current 6.6-liter Duramax V8 has a diesel particulate filter to meet today's standards. For 2010, GM will add a selective catalytic reduction NOx after-treatment system (along with the particulate filter) to meet the Tier 2 BIN and LEV 2 emissions standards. It will remain good to go in all 50 states.

[Source: GM]