Ive made numerous 1200mile round trips from IL to NC
I find no matter how fast I 65-100... As long as you accelerate gradually you will yield at least 25-27mpg.
Approaching inclines I tend to accelerate to 80-90 and let off the throttle some and let the mph drop off to the speed limit some times. By the time I reach the peak of the incline I'm going 5 under the speed limit or 5 over.
Its a 9.5-10hr trip one direction. I've made it in 8hrs before. 24mpg was the average.
lately I've been making the trip in 9hrs. with the average of 25-26mpg.
I've made the trip accelerating gradually and averaged 70mph and got 28MPG.
The time savings is worth the speeding And more $ spent on gas. More enjoyable drive with the ocassional WOT.
In metro area and areas where the speed limit drops from 70 to 60 or 65 I usually went 5 over. Some metros i cruised the speed limit. I do not drive with a radar detector. I scan the highway and look for spots where a trooper would be able to park hidden.
Out of the 18,000 miles in the past 2 years Ive seen 6 cars that at one point was in a "pack" with me get pulled over with in 30mins to a hour after they left the pack.