Just thought In would add that mine is 3mph off as well. And I am running 315's on the back. If tires were stock it would probably be a little more? I guess I would need to check the circumference with stock tires to know for sure.

It would be interesting to know if this would make our odometer read more than actual?

Roger

 

Mine is 3-4 MPH off as well....

 

I can't speak much for 993 and older models, but I drive 986/996/997/Cayennes by a "Your speed is" sign nearly daily, and 986/996 seem to be about 3 high, 997's about 2, and Cayenne's are nearly spot on. As previuosly stated, thats just how it goes.

 

http://www.honda-tech.com/zerothread...ostid=24990267

If the above statement is true, is anyone filing a lawsuit against Porsche? This is wrong .

 

mine is off by 4 mph

 

3-4mph here as well. Confirmed by GPS. UK car.

 

I've heard that all Porsche are off by the ~3 MPH I used my GPS and I get the same results as you are see as well. Mine is very consistent from ~25 up to 150 MPH (GPS 147MPH). 2001 C4

 

Yup. This is a pet peeve of mine. 3mph fast according to the "your speed" signs which seem to be pretty accurate measured in my other cars.

 

Mine reads 4 mph high as indicated by both GPS and those roadside speed monitors.

On the other hand, my S4 is dead nuts accurate.

 

So that means almost all of us are a bit slower than we thought? Think it would stand up in court if need be?

 

Mine was 1 MPH fast at 60 MPH on stock (new) P-0's according to my Performance box. My new tires are a bit taller and now at an indicated 60 on the speedometer, I am showing 57.