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...
My 04 Chevy does have the instant MPG and does not have the active fuel management. Like others have said I think it has to do with different trim levels. I believe on the 03s to 07s they had to have the steering wheel controls for the DIC. I drive a 2011 Chevy 1/2 ton for work and it doesn't have either the instant or average MPGs but will display the tranny temp. It is a base model with no active fuel management.