cirks

I know there's plenty of info (questions and answers) about over-rev reports etc. But one thing I find weird but may have missed info somewhere, is why the report only shows the engine hours when the last range 4,5,6 (etc) over-rev took place and not also the mileage at which it happened? Say, the last over-revs were 60 hours ago, that could be between probably 1800 miles ago (if avg 30mph in those 60 hours) to 3600 miles ago (avg 60mph). When looking to purchase a car or even just reading report on your own car, wouldn't mileage be more useful on the report than just the hours (particularly if a garage or someone else has had access to the car in a period before the report is done!)

arscottp

Hr and miles are both secondary metrics. What you'd really want it is engine revolutions since last overrev. Porsche decided to uses Hrs, so thats all we have.

cirks

Fully understand it's all we have but it just seems odd bearing in mind the ECU must be recording mileage for a number of other reasons etc. I agree number of revolutions would be more important in real terms to know what the car has done since the over-revs but mileage would tell you when they actually happened.

saabin

I'm sure it was just a design decision that Porsche chose to make back in the day.

Remember that the Bosch DME in these cars (997.1) is not the latest tech. It probably was based on the 996 ECU which now we are talking about dating back to around 2005.

Thinking about it, the "engine" part of the ECU would record just hours of operation. There are probably other subsets/parts of the ECU that handle the drivetrain/etc. It could be as simple as the designers wanting to simplify the code to be able to handle the overevs all within the "engine" module and not need input from external sources (i.e. drivetrain module).

Having written embedded code for a Motorola-based 68X based system waaay back in the day, I can say that these types of considerations were made in our design decisions.