I take that back, there was ONE guy I knew who could get around 30MPG out of a Silverado pickup. He had a lot of friends at GM so he knew exactly what codes to use to order the axles, etc. with the right gear ratios, etc. - and he would hypermile it, going max of 50MPH on the highway. He said he was flabbergasted because he would leave early, like at 4-5AM so that there would be plenty of room for other cars to pass him but a few of them just kept right behind him, acting like jerks because he was driving so slow even though the passing lane was wide open.
They were drafting. LOL Some people are just followers, I have seen this driving on State Routes with 55 mph speed limits and I would speed up to 50 mph and EV down to 35 mph which you would think would be very irritating yet people would follow you, strange.