Hello everyone new to forms but I own a 2012 ford Taurus sel. When i bought the car in 2018 I found out the hard way (got a $280 speeding ticket) that my speedometer isn't reading correctly as in the faster I go the slower it gets. When I'm driving 75 MPH I'm actually doing 85, everywhere I have searched and found nothing for a fix. I have taken it to a dealership and they want $1000 bucks to try and fix it with no guarantee, they said it was the cluster but I'm thinking someone before me put larger wheels and tires on it and had the speedo calibrated for those, then the stock 18s. I'm active duty Army and stationed in Germany now, I was seeing if anyone on here might has a fix.