I have a 2013 6 cyl ecco f150 2wd with 120,000 miles. My mileage is so so but I think it should be better, as the truck is only driven on the hiway. Depending on wind direction it can sometimes hit 21 but mostly averages 17.9

Someone who knows a lot more than I says I should be able to improve this with a good program.

Is this true or one of those interweb stories we here so much? And if true, any recommendations on what to look for?

Thanks
Rich