My car definitely gets better gas mileage going slower, or when my wife is driving. It also gets better mileage if I tuck in behind a fast-moving truck.
In fact, with the need for high air conditioning on our trip to Orlando, along with my aggresive driving trying to make the journey quickly enough to spend a good amount of time at a theme park on Saturday, I barely hit 40 mpg.
I’m driving my daughter’s mustang (which I try to max on the mileage the best I can) while she’s stationed in Italy for the next 3 years, so it’s either drive slower and use the cruise so I can use the AC or drive faster (AT the speed limit!! lol) and open the windows ~ which in FL heat isn’t much better than driving with the windows closed!
My sister once got a ticket for tailgating a semi when she was a teenager. The semi got on the radio and reported her because she was scaring the crap out of him.