My experience with Ferrari's shows speedo to be out by about 8%. Co-incidentally Ducati speedos are intentionally 8% optimistic. I have heard many owners claim their speedo to be accurate, but never seen it for myself. Private radar units are also prone to inaccuracy due to a lack of regular calibration, as is required with police units. My scepticism comes from using a data logger and particularly at the race track whilst pacing someone and biting my tongue whilst listening to the fanciful speed claims.Dermot said:My Stradale speed trap numbers at Infineon raceway just recently were very accurate with my speedometer +- 2%.. Maybe u just have a bad speedo?
Already stated that the car has ORIGINAL wheels and tires. I've talked to 23 other 360 owners that have tested their cars also and speedos were generally off 6-12%.woodenwheel said:If your non-stock wheels are smaller that would account for the speedo error.