Reply #57: I have experimented with different speeds as well

[madville]

I drive about 46 miles roundtrip everyday to work on a rural highway with almost zero traffic so I can go about whatever speed I want to safely. In my Toyota Tacoma 4wd 4cyl pickup I get:

20 mpg at 75 mph
21 mpg at 70 mph
22 mpg at 65 mph
25 mpg at 55 mph
28 mpg at 45 mph

I'm roughly getting a 33% increase in gas mileage by slowing down. I used to normally drive 70 everywhere, but have slowed down latey. I now drive everywhere between 45-50 mph(rarely get on the interstate). It works out to a cost savings of around $900 a year driving 20,000 miles with $4 gallon gas. Sure it adds 10 minutes one-way to my commute, or about 20 minutes a day but that doesn't bother me.