Got back yesterday 1420 mile round trip Michigan to Kentucky and back average mpg 29.8. Worst tank 26 including 2 miles in 45 minute traffic jam on I 65. Best 30.0 in northern Indiana flat lands. Lots of construction going on. Worse experence, woman driving a Mercedes tried to take the side off the Cad. Changed lanes without bothering to look. Lucky the shoulder wasn't closed.