Hello forgive me if this is posted in the wrong area im a noob to forums so here is my question: I owen a 2010 XD 5speed and I just got back from a 1,600 mile trip and when i got back on to 55mph roads i noticed my speedometer wasn't correct, I hade to do 65mph to be actually going 55mph and going 40mph i was actually going 30mph so my speedometer is off by 10mph. I noticed this when i passed by a speedtrap and i also went by the speed using my Gps. I'm running 205/60/16 on the car but I'v had those on for 8mths with no problems.... Any suggestions on what could be the problems? i was told maybe the speed sensor but i have vo lights coming on on my dash...... Thanks