boqueron

In Spain ( and even in Germany !) it can sometime happen that a seller has the temptation to modify the mileage ( kilometer ) counter of a car before it is sold . I have even heard that in some cases when they could not - for technical reasons - alter the mileage, people have substituted the original mile counter with a new one with less mileage... claiming that the original had a problem. All this is obviously illegal but in some unfortunate occasions if they can, they do it.

I have heard that there is a way to check the REAL mileage even if the counter has been altered or changed ( a chip keeping the information, etc..) . Can anyone confirm this and advise me how to check the REAL mileage of a 996 TT ?

Thanks in advance..

msindi

I know that the ECU stores total running hours of the engine and some other info (over-revs, etc...)

However, if you change ECUs you lose this data obviously so...

aj02996tt

When the 996TT first came out, there was a rumor that there was a "hidden" computer or memory device that stored the data you mentioned. Now that the car has been out awhile and torn down by tuners, I've not heard of anyone finding this device. Given that all Porsches have Event Data Recorders (EDRs) that store data in a crash (which can in some states be used against you criminally and civilly), I think that somewhere on the car there is a redundant data storage device. Whether it stores mileage is beyond me.

J.Seven

There´s no way to know the real milage, but from the ECU they can see how many hours has your engine runing, and they can tell you if the milage is close to what the speedometer shows in milage.

J.Seven

Martin S.

OBD III records hours...take the hours time an estimated speed, and you should approximate the "real" mileage + or - X....I would guess in a Euro car, 100 kph would be a start...just a guess though.

The best way is a series of maintenance records....

Moogle

if someone REALLY wanted to change the mileage, they would have to change out the insturment cluster, mabye change the ECU, other than that, there isnt anything REALLY permanent that stores the mileage.

get all the paperwork, service records, even better if it was all done at one dealer.

boqueron

Thanks to everybody.

WCE

The technology varies and I'm not sure what applies to Porsche, but in many cars the digital odometer is just a "display" for data stored elsewhere and communicated via the local network connections, usually the "body control" or similar module. Others actually do store the mileage right at the odometer display "module" built into the IP, reading the vehicle speed off the network. Since both of these techniques are basically tamperproof without replacing the associated module (which I presume would be "controlled" by Porsche) concerns about odometer tampering are a lot less than they used to be. I've never heard of a backup "master" odometer scenario, but it certainly would be easy enough for them to do.