Just got my 05 manual a week ago and I am getting horrible fuel economy! I refilled and tried to shift early at 2K to see if will improve, but still nothing? First half tank netted me just over 100 miles. At 80mph on highway, this car runs at 3k rpms in sixth gear? No way to get mpg's like that. I am looking to get average city/hiway mpg of low teens. Thats no better than my Ram Rumble Bee that I traded in to get a fun car with better economy. I like the xf but almost wish I had my Bee back, power and looks too! Checking the plugs this weekend and air filters too. Something has to be wrong.