computor settings...fuel usage/milage...

Took my V6 Double Cab 2012 on a 360 mile round highway trip. First time NOT pulling my 1,200 lb boat. Ran 80mph on a straight flat partially on the way to the destination, and 75-79 on the way back.
It SEEMS as though the milage [Ultra Gauge] stayed about 16 mpg for the first 30 minutes of the trip, then upped to an average of 19 [about]. Does the computor do any changing of specs when an engine has run at cruising speed after 30 minutes, maybe the spark knock adjuster doing it's thing?
Just wondering. Of course it could have been my driving or the incline of going from lower elevation to higher, or vice versa.
Having an ULTRA GAUGE sure makes one hate to see uphill grades coming!

It also seemed to get just as good fuel milage at 78 mph as it does at 70 mph. Not an exact enough trip but just some observations.

My 2012 4x4 Double cab has just turned 16Kmiles and I am enjoying this truck more, and more, and more....!

 

I just drove 218 miles: some city/mostly hiway(75-80 mph) and got 26 mpg! I wonder if it was because I poured a bottle of Techron into my tank prior to leaving. Going up, same miles and destination I got 21 mpg and return was 26 mpg. Quite surprised!