53 plus MPG over 1500 mile road trip

I picked up a used 2011 Prius in Fort Worth, TX the other day. I drove over 1500miles to get it to my home in Naples, FL. I was able to achieve an average of over 53 mpg by using a little bit of hyper-mileage techniques including driving behind tractor-trailers and driving about 5 to 10 mph under the speed limit. I don't recommend the drafting if it's relatively close behind due to road hazards, rocks, etc.. I was just a little closer than a normal interval behind - perhaps 6 to 8 car lengths and only did this for about 10 to 15% of the driving. When I did, I averaged about 70 mpg. At 70 mph, I was only getting about 46 mpg, which is much better than my '94 Corolla!
I used the Advanced Technology Package features during the drive including the radar cruise and lane keep assist. These two features lowered the fatigue of normal driving. You can't let go of the steering wheel, but it does assist by turning the auto back on track, which I didn't expect. I expected it to simply warn you with an audible sound. The radar cruise is nice, but they need a software modification to smooth out the throttle responses to changes in speed. It was a little rough in that regard.