Originally Posted by DeeezNuuuts83
I know the needle and speedometer are digital, but why does the needle shake like that?
It probably doesn't have any algorithm built in to smooth it out. Our digital readouts on our engine dyno cells jump and shake like that as well*. It is snapping a picture of the engine speed and displaying that "picture" on the tach.
* We use digital displays so we have flexibility for what is displayed given the test we are doing.