speedo is off
I drove by a few of those speed detectors that they put on the side of the road that tell you how fast your going and my speedo is off by 3mph each time I go passed one of those things. The speedo says i'm going faster than I actually am. Why would this be. I didn't change tire sizes of rims or anything. Its not putting extra mileage on cuz I compared the actual miles to my work both on my truck and my mustang and they are both the same and the mustang speedo is dead on the actual mph. Any ideas?
05 EDGE 4X4--K&N CAI filter--4.10`s
04 Mustang GT--Predator tuned--MGW short throw shifter--MAC catted H--Flowmasters--BBK CAI--FRPP 4.10`s--sportline lowering springs--tokico shocks/struts--mm cc plates--steeda uca's