Speedometer off by 5 mph?

[Glenn Wasserman <glennwa@domain.elided>]

Is it possible for the Speedo on my '93 Spider to be off by 5 MPH at all
speeds? That's what I've measured, but it doesn't make sense.... if the
tires size is wrong, I would expect a ratio, not a constant measurement.

It reads 5 mph low, by the way...

Thanks,
- -Glenn

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