My Jeep Liberty get about 25 mph running around 6o-63mph. That's on the freeways here in Dallas, some slowing and a bit of speeding up, but I prefer to use the engine rather than the brake.
At 70-75 mph on say I 70 or I 40, I get around 20-22, depending which way the wind is blowing. Seems I rarely have a tailwind.
Pulling my bike trailer, about 15-19 if I can keep it around 60.
The problem is if I'm going from Los Angeles to Cleveland, I don't want to HAVE to drive 60. That's close to 4800 miles / 70-75 mph = 3 solid days of driving 24 hours a day with no stopping at all. Slowing from present posted speed limits to 60 mph would add over another 24 hours of solid driving.
And you guys are right. When was the last time a senator or representative actually DROVE?
Mary