[oil pan 4]

A 2012 2wd 3/4 ton chevy suburban with modern fuel injected 6.0L with cylinder deactivation and overdrive transmission with converter lockup is rated to get 10MPG city and 16MPG highway.

You would think after 26 year, the addition of fuel injection, an overdrive transmission with lockup converter, cylinder deactivation and a 1.4L smaller engine and some actual aerodynamic considerations the fuel economy would be better a lot better.

This is what I have. An obscenely over sized engine that dates back to the 1960s, carburetor technology from the 1970s, ignition system from the 80s, no aerodynamics to speak of and using a cheap parlor trick where I cut off the engine and roll for a little ways.
The most modern piece of technology is my AEM wide band O2 meter.
(that AEM wide band O2 is worth its weight in gold if you want to tune a carb)

Now I don't ever plan on taking this pig in its current 7.4L, 3-speed with 4.11 gear configuration on a road trip and finding out what its highway MPG is.
I would be surprised if it got 15MPG on the highway.