Opinions please; 2009 Silverado LTZ 2500HD Duramax

Personally, if you can find a version of the truck that uses DEF, that's the better way to go. Yeah it means topping off an additional fluid, but the regeneration events were cut down drastically, fuel dilution was cut down drastically, and EGR flow rates went from being in the 40% range down the around 10 or 15%. For the post 2007 emissions world, DEF is a god-send as far as I see it. GM and Ford was equipped in 2011, and RAM went to DEF in 2013.