So I was reading my owners manual and read about an option tha allows a couple cylinders shut down during highway speeds to help conserve fuel consumption. Very innovative ... does anyone know if this only is an option for the 8-cyl engine or offered in the 6-cyl too? Also, does anyone know the build code for it? I haven't made it to the dealer to get a build list yet. I'm just curious, I like knowing everything possible about my Trailblazer. Thanks.[/b]