2014 sierra 5.3 questions about active fuel management

[DominatorZ71]

3 hours ago, 16LT4 said:

 I hadn't looked at the lifetime mileage in a year, and today noticed that it has gone down in that time due to the changes I've done to the truck.  28 is great for a full-size SUV.  The 400 mile average of 24 mpg was also only within the last year, not since new.  Based on the lifetime mileage, I don't think the PO used E85 and likely stuck to the goldilocks zone of 50 mph roads.  If I used 89 fuel, went back to lower-resistance tires, stock aero, and didn't tow-haul what I am currently, I'd get the lifetime mileage (and all the other displays) back up.  From the displays, you can see the "bests" of the last year; current numbers are low due to hauling a 2000 lbs of firewood, and sand/gravel on the current tank.  I've also only been locally driving the truck with stop-and-go and haven't done a good highway trip with it in a while.

 

So: at 90k miles, the lifetime was 30.4 mpg.  Now at 102k miles, the lifetime is 26 mpg.  also don't forget, those figures are also under-reported, as I didn't have the speedometer corrected when I added the bigger tires; it is off by a few mph compared to GPS.  So, the 26 is more like 27 mpg.  And that's on E85 for the last 3+ years. 

Nice certainly good mileage for a v8 pickup