Here's some first hand comparisons with a light load. My son recently traded his 2011 tundra for a new ecoboost. He often uses a 16' vee-nose cargo van to haul his Harley; gross weight of about 2500#. With the tundra, he typically got about 9 mpg. First trip with ecoboost netted 12.1. He was impressed with the improvement in handling as well as economy. I went with him on a second trip which marked only 10.6 (no, I'm not that heavy). Last year, I pulled the same rig with my 2013 gmc with a 5.3 engine & got 12.0 mpg. With the addition of a second bike & some gear, topping 4k lbs, my ecodiesel recorded 15.8. Probably not enough of a controlled test for some but telling results for me.
