Right. Not the problem. If it were, my odometer would be off. It's dead on. My revs are set at 765/mile which is right according to the tirerack website and my observations with the freeway mile markers. Also, with gear discrepancies your speed wouldnt hold a constant deviation. It should be farther off the faster you go.
I just need that stupid little needle adjusted two ticks to the left.

 

I think most speedometers read alittle fast, motorcycles being worse than cars.
My GPS always reads 2 or 3 MPH less than the speedometer.

 

I'm sure you're right. It just bugs me. I hate to have to think when I'm driving.

 

It makes the miles rack up faster than they actually are.
Ford has gotta love that.
Oh yea, they had a hand in the calibration in the first place.
Hmmmm.....

 

Ford (and most manufacturers) make the speedometers very optimistic. I was checking mine against my GPS on a recent trip and when the GPS said 65 my car said 66. At 75 the car said 77. I know the GPS won't show how close it is to the number, like it won't say 65.6 or 65.9, but it is definitely off. My tires were just checked and actually a little overinflated to 35 psi. Stock gears, tires, etc.
I wonder, if it was off by a growing percentage instead of just one or two mph, would increasing the tire size a little fix the error?
Any mathematicians?

 

Car speedos aren't all that accurate

 

the odometer is not affected. check the OP, he measured the odometer and said it is right on.

if it wasn't, ford would be looking at a class-action lawsuit. it happened to honda:

http://articles.moneycentral.msn.com...sOdometer.aspx