I recently passed on a low- milage 993 which looked like it had experienced a much harder life than I would have expected based on it's odometer reading (@40K).

My understanding is that these units tend to break.

A few things could have happened:

1. Hard life for the car indeed?

2. Speedometer/odometer broke and was not replaced until owner decided to sell the car.

If a speedometer/odomoter is out of commission for a while - will the cars ECU/computer on a 993 continue to register the "true milage?'

If so, when you have a PPI can it be flashed to verify that the true milage and odometer reading match?

Or, is the odometer purely mechanical?

It was not uncommon for owners of Ferarris to just unplug the units (when these units were purely mechanical in the 70/80's) to avoid racking up miles.

Any significant miles on a Ferarri really hurt its value.

Was this illegal - absolutely.

Did people do this - yes they did, all of the time.

With the newer electronic odometers, it's not possible.