[slowmover]

The switch to DEF engine tuning brought MPG back up on later trucks. Your numbers are what I've read with others. Where did you start on MPG and how much improvement has been made?

I'd fill it at a station 30-miles or so from home out on the Interstate and run it another 100 miles or more round trip back to that same pump. Cruise control at 60-mph. Fill tank both times same way and only to first click off. Consider this baseline Hwy MPG.

Using that highway baseline you should be able to get within 15% in the city. A goal.

Much depends on how far you drive annually as to the effect on the fuel budget. And how long you'll keep the truck.

In my case with a 2WD now at 210,000 I'm not far from having spent less than half from an ordinary owner with a 4WD, auto trans, minor lift and who has had to rebuild front end plus convert to post 2008 steering wheel who's covered the same miles. In other words, I could or have bought and run two trucks. So it's not just MPG in contention.

There are tuners and such that change things. Past legality, will they pay for themselves? Will they short n engine trans life (usually yes). Etc.

Tires are otherwise the big change. Highway rib closed shoulder best. This can be 1.5-2 Mpg to the average.

Others to check are steering slop, from column shaft to wheels, alignment, brake drag and CAC leaks. Weak lift pump.

A bed cover will help. See the half tonneau idea here and consider making one from plywood. Side skirts. Better front air dam. Synthetic fluids.

See post by Big Dave