Tach reference
 

2006 RX8... Should there be a tach reference while cranking?

What do you mean tach reference?

Like a movement in the tach when cranking. Aka starter is moving the engine at 500 RPM would you see that be reflected in the tach? Yes I believe when you crank you're car it will move the tach. But I haven't started my car in a min and looked for that

While engine cranks most cars, the tach will jump as engine turns.

Never really paid attention to that.

If you want to get an accurate cranking RPM number, use a live data capable OBD2 reader and put your foot down on the gas pedal, then crank. The reason is that a healthy 8 will start before the OBD2 picks up a consistent number.