6 speed auto has been averaging 48+ on the highway, on a recent trip from MI to KY I hit 49 on the way down and 51 on the way back (1 stop 420 miles) with a peak of 55 while in the Fort Knox area.
On my 8,000 mile trip, overall was 48, peak was 65, (I check at each fill up) low was 45. Some highways have an 80 MPH limit some 65, depending on state, terrain, road type has a huge influence, good asphalt vs messed up cement, in short the noisier the road the whose the MPG. But the 65 number was at 80 MPH on the I-10 climbing from just above sea level to over 3,000 feet (I use the dual screen function and watch my elevation on trips closely), I will discount my MPG on the I-40 down hill at 70....
I run 35 PSI in my tires...
City if I can miss the lights is crazy high 89, its the lights and stop signs that kill the MPG and average 35-38 in town.
BTY I use the cruse a lot, and in town too....