Well, I just completed a very interesting experiment.

I went to Spokane WA on Monday, worked there all week, and drove home today.

I filled up before heading out, and drove right at 70 mph +/- about 2 mph the whole way. When I got there the odo showed acouple of ticks under 300 miles, but since it reads 2% low the actual was 306 miles (verified by GPS). I filled up with 11.8 gallons for a total of 25.7 mpg. Not too impressive.

Then I drove around town all week. Mixed driving on city streets and the highway - but all 60 mph and under. I racked up 198 miles - which with a 2% adjustment is 203 actual miles - and when I filled up again before coming home this morning it took 7.2 gallons for a total of 28.2 mpg. Much better.

So as an experiment I decided to drive ALL the way home keeping it at 60 mph. I set my GPS to beep at me everytime my speed got up to 62. So for 4-1/2 hours I drove a steady 58-63 mph, and when I pulled into the gas station in my neighborhood, my odo showed 271 - which is 276 actual miles. I filled up and all I could get into the tank was 8.4 gallons! Even with rocking the car and doing everything I could to get it to take more.

That is an amazing 32.9 mpg! I know the last long trip I took I got just under 32 mpg driving an average of just under 65 mph - and everyone said my numbers couldn't be right. Well I KNOW this is correct. Averaging 60 mph is definitely the way to go if you want to maximize your mpg...

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1984 300 Coupe TurboDiesel
Silver blue paint over navy blue interior
2nd owner & 2nd engine in an otherwise
99% original unmolested car
~210k miles on the clock

1986 Ford F250 4x4 Supercab
Charcoal & blue two tone paint over burgundy interior
Banks turbo, DRW, ZF-5 & SMF conversion
152k on the clock - actual mileage unknown