PFTD: Make your gas work harder

I found the following 4-step way to make the 'gas work harder'.
1. If you have to drive on a freeway, allow extra time and drive at a steady 50 miles per hour when traffic conditions permit -- even if the speed limit is 60 or 65 miles per hour.

2. Keep your tires inflated properly and (3.) empty your trunk.

Doing this should increase your mileage 10 to 15 percent.
3. Finally, bunch your trips so you only drive one day on a weekend.

I would never do the first one; but next three are worth following. I think driving 15 mph below the limit may increase the risk of a crash on the roadway.