What new gen Challenger is best and Why?

Is there any real MPG difference between the v6 & v8?
Real world in my 14 Charger R/T is 19 average mostly running in the city. Two long trips I took, one from STL to Orlando and back and one STL to Indy and back averaged 27.3. Too me not enough of a difference to go with the v6. Besides when we bought it my wife preferred the way the R/T drove and handled over the V6 so that pretty much decided it.