Where is the Active Fuel Mangament Showing...

Absolutely loving my truck (NBS '07) and going to get my first oil change this week.  Very curious about the MPG's after that and wondering how I know, or even if I know when the motor is cutting down to the 4 cylinders.  Thanks in advance for any replies.
 
 

It is in the DIC display, thumb through using the top button until you see "Instant Fuel Economy" on the left and "8 Cyl" on the right.

I have traced my mileage since owning the truck and it goes as follows:

E85: 13.7 mpg
E10: 14.8 mpg
87: 15.1 mpg

This is since April 07 and is about 25% city/75% interstate. The best mileage I have ever seen is 17.6 mpg.

Did you have cross check the mpg reading in the DIC? I calculated manually and found it to be off by a bit. For instance I check it on a trip that was a totally highway trip and it said I got 17 and some change and manually it was just below 16. I reset it at every fill up. Just food for thought... might want to calculate manually to get actual.

Appreciate the posts..................So if I don't have the buttons on the left side, just the regular trip, odometer button, where do I look?
 
Thanks