I happened to be in the area today, so I tested my route for the final leg of this trip at a "hypermiling" pace as a reality check of "the plan". Here's what I found:

The standard Google route is 73.3 miles and Google says 1:32 to drive it.

My chosen route was 69.8 miles, but allowed (and required in some places) lower speeds for better mpg. The only question was whether I would make it within the alloted time.

The "official time" for the leg would be the Google route mileage at a speed of 45 mph. (which I absolutely would not recommend, because a good portion of that route is on I-4) So, 73.3/45 = 1:38 which is surprisingly not much more than the Google prediction.

How did I do? Well, the Scangauge read 51.9 mpg at the end, having peaked at 52.6 before getting into Tampa. (that would correct out to somewhere around 50 mpg due to the slight inaccuracy of the Scangauge and my tire size) Not bad considering the A/C was on the whole time and I could have milked it a little more than I did. But, as it turned out, we reached the finish 7 minutes late!

What does this mean? Well, we made two minor wrong turns (poor directions from Google, go figure) that might have cost us 3-4 minutes. The rest could have been made up by just driving the speed limit. Anywhere the speed limit was 55 or 60, I was driving about 5 under. And I didn't even know what my target time was while I was driving, I wanted to know what my "natural" hypermiling time would be.

So, a target of 45 mpg average will work, but it's going to keep you on your toes to maintain that fine balance between "adequate speed to beat the deadline" and "maximum fuel efficiency". It will be a challenge, indeed.

I'd love to see more people signed up for this... but now I've firmly got my challenge on with myself! 55 mpg, here I come!