Here is the real life test - not really a test, just a recording from my normal daily commute.
https://youtu.be/HGcr5Ug_m6s
I started in residential street (with 25mph), stop sign at every intersection. Finally when I stopped at traffic light going to main street the computer showed 13mph.
Then after driving about 45mph and passing few traffic lights I drove through old city with speed limit going down to 25mph. Again some traffic lights, stop signs and roundabouts. Finally when I arrived to the main country road the computer showed 18mpg.
Country road is mainly 55mph with traffic lights or stop sign every few miles, also passing through old town with 35mph speed limit. However past that town the computer showed 20.5mpg
Then just steady driving at posted speed limit 55mph with occasional stops at intersections, after about 10 miles the computer established at 21.5mpg. And that was to the end. Of course when I arrived to my destination city and finally parked the car the the mpg computer dropped showing 21.3mpg.
This is all stock 2012 SR5 4x4 with running boards and KO2 265/70R17 C-rated. Tires are inflated to 38psi for quite comfortable ride. After that trip I check tires - they we cold.
Update: After I got back (almost the same route) with a little bit of traffic in towns the computer showed total average (both ways) 21.2mpg.
I think 4Runner has the best gas mileage when it runs at steady passe 45-55mph. Higher speed gives more air resistance, at lower speed and the engine/transmission runs below optimal gas usage. That speed will probably give you up to 24mpg, but this kind of driving would be only for EPA test, not a real live.