I bought it used with 30K on it. Just went through the FCA emissions upgrade and have found that my mileage did improve or go down, however, it runs much better and in Sport mode it literally flies when you mash down on the fuel pedal. This is my second Jeep. My first was an '86 Comanche 4X4 long bed XLS with the 4 cylinder and a 5 spd. manual. Although I only have 72K on this Jeep, I'm considering a Gladiator Rubicon when the Ecodiesel is available.