Diamondpilot
Super Star Member
- Joined
- Jan 18, 2007
- Messages
- 16,316
- Location
- Daleville, IN
- Tractor
- Jinma 254/284 Ford 861 Powermaster at work
When I got a GPS, I found that there was a 3 MPH difference between the speedometer and the GPS on my 2007 Jeep Liberty. Then I noticed the same thing on 2 rental cars, and on my '96 Silverado. I thought maybe it was the GPS, but then I ran through one of those speed checker/warning things, where they have a radar gun setup with a sign that says "Speed limit XX Your Speed YY". Matched the GPS exactly. Since then,and as late as today, I have been through a few more of them, and the speed always agrees with the GPS. Makes me wonder if there is some kind of deliberate error built in to the speedometers to fudge the mileage ratings, or maybe by secret government mandate to slow people down a couple MPH. Same error on 4 different vehicles seems a little to much of a coincidence. IF the GPS is accurate, all those vehicles read 3 MPH slow.
Speedometer will lose accuracy as tires wear. I have checked every vehicle I have owned for the last 20 years. None were more than 3 mph off at 70 mph at any given time.
Chris