1. Driving at a considerably slower speed on the federal highways (the older 55 MPH limit);
2. Jimmy Carter gave televised advice [1] while wearing a sweater -- suggesting that his thermostat was set a little colder in winter;
3. Proper tire inflation and maintenance of your car helps with gas mileage;
4. Carpooling. Shoot I even did this when I was a practicing attorney -- which is funny, considering that my dad built a few refineries.
5. Following, a safe distance behind a semi truck, also helps. I do this if I have a very specific amount of miles I can count on my car to go, before refueling.
I'm a little surprised that the current Democrat administration doesn't take the Jimmy Carter approach. Instead, we are being told that we can skip funding the highways by eliminating the federal fuel tax -- sending the signal that gasoline is not that precious.
[1] https://www.washingtonpost.com/archive/lifestyle/1977/02/05/...