I recently purchased a 2013 GMC 3500 diesel truck and on the dic it will give me average MPG and the owners manual states that instant mpg is available if so equipped. My question is is it a software...
On my 2005 Chevy 3500 the DIC was always off, but on our 2011 it's right on, usually within a couple tenths of a gal on fuel used and the avg mpg is also within a few tenths of hand cal. Yes the '05 did have instant mpg, but just let up on the pedal a little and mileage would shoot up. Saw 99.9 many times so I really don't miss that feature on the '11.