I have a dually as my signature says and have a tts xtreme on the way and was just wondering how fast my 1/4 mile times should be with the xtreme on fuel only.

I would think you should be somewhere are the 13.7 - 14 flat range depending on where your at. The closer to sea level and the better the air the closer to the 13.7. The non dually 4x4 trucks are right at 13.2 - 13.4 range some event quicker so with the extra tires and weight you will be a little slower.