Fuel mileage still sucks

[Yauchout]

(10-28-2021 )Lead_sled Wrote:  67mph is slow here in Texas. You drive 57mph here and someone will run into your back bumper. Speed limits here range from 75-80 on the interstate. Where I run is pretty much 75.

I’d be content with 6.5mpg. Not looking for 7+, but I know it capable. I just don’t know where the problem is

no one will actually run into your back bumper at 57 i worked for prime inc for years and ran new york to riverside and back in my governed 58 mph truck you are never gonna get 6.5 at 70+. i use to be on a dedicated route that ran from decatur alabama to waco texas that had to be ran in a 11 hour shift to deliver on time at 70 + in AL, MS, LA and 75+ in texas and the truck would do it and did do it from the time it was new until it hit around 350Kmiles but only did it at 4.6 mpg and I paid for it later with long term wear problems from pushing it that hard