Speedlimit ranges between 55-70. I am rarely below 65 unless a truck is slowing me down. I believe the 20 mpg pic I was averaging about 72 mph until I stopped for fuel. I always use cruise and never hypermile. The route is 77 to 81 to 276. It's ~580 miles one way and I do that round-trip a week. I'm not sure why anyone would expect a massive fullsize pickup to get 20mpg at 95 mph? There are quite a few sections of 81 where the speedlimit is 70 and I run 85. But I am far from a conservative driver. Also, based on the nationwide general average between 65-75 mph I assumed that was helpful information. https://en.m.wikipedia.org/wiki/Speed_limits_in_the_United_States_by_jurisdiction#:~:text=The%20standard%20speed%20limit%20is,mph%20for%20all%20other%20highways. Edit: average speed was 70ish for the 20.1 above southbound from Trenton to VA down 81. I left at 415 and stopped for gas at 1045. Hopefully that fully gives all the details. I'll allow whomever to determine the total altitude changes, since technically those are relevant too. I did stop at chickfila at some point during this trip so the average is a little skewed, but that should give a close enough picture.