I average 15.7 in the city right now, but that is also at sea level. Haven't taken the beast on the highway yet, but I will update with my numbers once I knock out a road trip. Truck isn't even broken in yet. Still haven't hit the 1,000 mile mark. My 2008 Ram with the 4.7L was averaging 15.1 after 32,000 miles had been put on her.