Looks like the Duramax will be going to urea injection for 2011. About $10-15 to fill up every 5000 miles. I guess it has pros and cons like everything else. But it made me curious to know how their engines currently work. Apparently they use the same Bosch CP3 pump but do they have multiple injection events like the Cummins engines?

 

Would assume so, that was the whole point of common rail. Multiple, controlled injections for better emissions.