I love my 5.7 liter Dodge. I have a single in dual out flowmaster and recently installed a cai and an exhaust cutout. It sounds mean! I am getting a total of 18.6 mpg highway. I got a total of 480 miles on a single tank of gas it was 90% hwy and the rest city. This truck rocks! It's far better than any 5.6, 5.4, 0r 5.3.