speedometer runs fast when cold

[Mustang5L5]

Maybe the magnets in the speedo something something when its cold?

Ding Ding Ding

 

[Shaolin Crane]

It's the speedo head that's the problem.



He's right.
The stock tach isn't known for accuracy. I have a calibration test jig that proved that the stock tach may be off by 200 RPM or more.

For the record, i was joking. My stock tach was off about 800 rpm at 5000. Its nice having an accurate tach.