I know this topic has been done before, but I was surprised by the accuracy of my speedo today as most owners report up to 10% inaccuracy. I was clocked officially today at Woodbridge doing 151, and my speedo indicated 151. Spot on! The old technology on the 328 is much better than the modern cars it seems. Another driver that was in a 360M reported clock speed of 180 but an actual speed of 167. Nigel.
I was also @ Woodbridge and yes Nigel the findings were interesting. My 355 spider had a clock change from kms to mph 2,500 miles ago and I have to say it was spot on - trying to read the clock and drive though at 166 is a bit un-nerving! So I think with all things Ferrari each car is individual and no surprise that some cars have inaccurate clocks!
I was also impressed with the accuracy of my speedo this weekend..bang on with the GPS. I was more impressed with the speed (German Autobahn) - over 250kph with the roof off! F.U.N.