I also own an EcoD (Notice I don't abbreviate it as much). So far, I love it! Fuel mileage is great. It pulls what I need. I did have it tuned since the first tank, and I would be happy to discuss that if you want on a private message. The biggest downfall is that this engine was designed for use in Euro Cadillacs (The Oil Cap say GM underneath!!). It was not designed for an engine driven fan. Cooling is the biggest issue, but the engine does go into protect mode to prevent overheating. Changing out some of the poor flowing grill inserts have helped. Some people are also removing the shutters to try and get a little more airflow through the cooling stack. Just changing the grill inserts reduces the J2807 tow test by about 1 minute and increases lowest speed by 15km/h (engine does not derate as much) (Green Diesel Engineering Test)