Highway is supposed to be 30 mph., but there are a lot of variables. See the article on this that was posted today.
Glad I waited for the SRT Haven't check it lately, but this was the trip home with it cruising above 70MPH But that is with a Manual 6-speed
i can get up to 26MPG on my 2009 RT. driving the interstate. usually the average is around 22 overall. and I am running the 91oct tune on my trinity running 93 gas.
On a trip from Nashville to Columbus Ohio, running 70 to 75mph, I averaged 27.6mpg in iny 2016 Scat Pack Challenger on 93 Octane gas. Honest numbers! I was amazed. It's never unusual to see 25 to 26mpg on most trips. Darn good car.