Speedometer Adjusting?
 

Ok maybe im retarted but I heard theres some legal way to adjust your Tachometer showing your miles on the car. Adjusting it to the correct miles on the engine or some sort. I never checked into this, but I just wanted to know the full details. Is this information wrong or what. I read a how to guide on how to set it back (legally) not too long ago. Can anyone help me out on this?