So have a 10 hour drive from Texas to Iowa coming up tomorrow, with the return trip on Monday — my “navigator” is my 16 yo son, and we are going to Iowa for a youth triathlon. My wife told me to take her Pathfinder — I declined and decided to drive the Mustang (in case you were wondering, his team has a trailer and takes the bike and related gear for us). I’m not sure how this is going to work out, but what the heck. So what kind of mileage do you think I’m going get?

[UPDATE] Well, with a fair amount of in-town driving, I ended up averaging 20.1 mpg for the entire trip. I noticed two things dramatically affected my mileage. First, of course, was speed. My average mpg noticeably dropped (for those few seconds I was) over 80 mph. Second, I averaged about 1 mpg less on 91 octane versus 93 octane. Because 93 is so available in North Texas and I never put premium gas in rental cars when I travel, I didn’t realize the number of stations selling 93 octane was so limited other places. In Des Moines, I was able to search for and find some. But on the highway, it was hit or miss (and mostly miss). Perhaps my driving or the terrain could have caused a bit of that difference, although I don’t really think that is true.  

Edit: I don’t know why Kinja is rotating my picture. Sigh.