Intrigued by Rich B's semi-experiment, I finally completed some gas-mileage tracking:

Test     Speeds    Mi.   Gal.    MPG*
------   --------  ---   -----   ----
Tank 1   Normal**  325   15.24   21.3
Tank 2   < 65 mpg  355   16.22   21.8

I drove a whole 2 1/2 weeks without exceeding 65 mph and saved a whopping .5 mpg! I was also very conscious of my AC/Windows situation as well. I guess this means that you've got to drop below 60 or less to really start to see an improvement. Or maybe only worry about it if you're in the midst of extended highway driving.

* My car's estimated MPG is 19 city/ 27 hwy
** Normal driving includes occasional speeds between 75 and 80

P.S. Good to see the old PRE tags still work.

Labels: gas, research