I’m getting around 18 MPG and I’m seeing on YouTube the same truck get high 20’s and even 30 MPG. With not knowing what the previous owner did as far as maintenance. What can I do to get those kind of MPG?
My mix driving average on the truck's computer is 27 mpg. After driving on the interstate for a couple hours at 77mph (my cruise control speed) it bumps up to 29. I use Rotella T6 or Mobil 1 Turbo Diesel Truck 5W40 oil. But most importantly I am using an ECM that was tuned by Green Diesel Engineering. Best 750 you can spend. It gets you better mileage and your engine won't grenade.
After that it is all about your driving style. If you are driving stop and start in town or otherwise very short trips - you are doing yourself no favors. You should then get a gas truck. Diesels are made for the open road.
I get 22-26 driving 55-70 to work stop and go. Highway I can flirt with the 30’s if I’m driving sensible. But my foot gets the best of me and I like making it whistle lol. I am unaware if the previous owner has tuned or done anything with ecm as I believe the truck was strictly commuter vehicle.