I've had the tach read a bit high on my 09 America, mechanical speedometer. Have only seen it a couple of times. Noticed it the first time after changing fuel map/tune with TuneECU. Don't know if it that had anything to do with it or if I was just paying more attention. When the engine was turned off the tach still read around 1000RPM. Didn't do anything to fix it. After a couple of on/off cycles it was normal again. I haven't seen it happen again in a long time.
