Just read up on this, did not know. Is there a way to visually tell if the "head to cylinder seals" have been taken care of? I assume this is what you were referring to. I think I need to pick up "The Used 911 Story, 8th Edition by Peter Zimmermann".

No visual cues.
Ive been told the lack of leakage at 70-80K miles means its good with or without the modification.

Service records are not the end-all, be-all for me. I like them. I like a service booklet stamped at the proper intervals.

But condition of the car, and how the owner treats his house and other cars gives me much more information than ANY stack of receipts. A full service history from the beginning plus window sticker adds value. Absense of same does not subtract value. And I would rather have a car with great paint and a stellar interior with no records as a starting point than the same year/model car with all records, spotty paint and crap interior. As was said by others, the car's condition is paramount.

As for why some folks keep records (and even notebooks) and some don't:

I keep records because I don't always remember what stuff has been done to what car and when. I keep records for my own information, not as something to pass on to the next guy. In fact, my personal habit is to buy a car and run it until it fails or until parts are unavailable to fix it. An example: I once had a '78 Scirocco that had a repair folder that was at least three inches thick. And I would still have that car, except for somewhere in it's life, some @$$hole cut the top for a AM sunroof. Which, no matter how hard I worked at it, never stopped leaking. One day, I stepped into the car and my foot when through the pan. That was the end of that car. :(

Records are nice. But lack of them is not a deal-breaker.

My 993 had no work history of the wiring harness being replaced and nothing mentioned in the Carfax about it. I looked at the part number on the harness (the ink had rubbed off in places) and it looked like the correct, newer one. I called the dealer and he confirmed that it had been replaced on my VIN. I asked very nicely if I could get a print out on that and he said there was nothing to print out nor was there a date for it.

Speaking for myself, one naturally buys a car based on condition but I really want service history to go along with it. It can absolutely give you an idea if the car had been cared for (like the 69 above) or not. Interestingly, I'm a commercial pilot and keep meticulous records on the cars I drive, Porsche, daily driver or wife's car.

Interesting how this thread had unfolded. I bought my 89 Carrera last December and everything checked out except it had zero service records. Low miles, straight as can be, dry engine, PPI and then a complete once over from another Porsche specialist.

When I was debating buying the car, a lot of feedback really emphasized the importance/necessity of buying a car with a documented service history.

I guess it is just a supply/demand thing. If it is the car you want and everything checks out but there is no paperwork, you have to make a decision to to take a chance or wait.

In my case, I am glad I pulled the trigger. The car has been flawless so far, I drive it a lot and prices seemed to go up the G50 cars right after I bought it. If I ever sell it, I will at least have a complete service history for the years I owned it.

History
 

Yes I'd rather have it than not, but agree that its not a reason to reject cars as most cars that have gone through a dealer and/or auction have lost documents. Thats the majority of cars at this point. I do adjust price based on what's known and what's not.

I ignore claimed rebuilds, clutches low miles claims, etc. if no documentation. The majority of car listings that say rebuilt don't have documentation so I have to assume the worst and hope for the best. The PO told me he rebuilt,... is worthless unless I can see the parts/work.

To me running a CarFax and similar is worthwhile to see if mileage matches (but not much else). I've seen a lot of cars that the odometer and Carfax/carcheck don't match, although only helpful on 1980's on cars.

But IMHO A PPI IS BETTER THAN SERVICE RECORDS. Service records can be fudged, they won't tell me if wear matches odometer, accidents, paint, rust, leaks, low compression, and on and on.

Obviously a PPI and current condition is important HOWEVER documentation is KEY to attaining the highest dollar when a car appreciates into a true collector car instead of just a fun, enjoyable used car.

Remember 15 years ago early 911s sold in the teens...people didn't care for them, threw out records, etc. They didn't value them. Now people will pay more for early 911s with records that support the provenance (and actual mileage recorded) of the 911. This can be big dollar differences, and sometimes sellers don't understand this when they see high prices for their car being sold by others and wonder why they can't attain the same. I'd rather have full documentation back to new than the original toolkit. You can always replace the toolkit...you can almost never replace the documentation without significant amount of $$$ and luck.

So according to this statement, if I have a random 911, let's say a 1973 911t, with the full service history it is worth $X. However, if I throw out the full service history (and thereby create an absence) then it is still worth the same amount as 'no value is subtracted'?

Help me understand the logic here.

Service records show history, which is important for value as car ages. Provevnance is key in any collectible. Carefully kept records also show a meticulous, interested and organized owner. They can also help in diagnosis of problems.

It's false to say that two cars of equal condition, one with records, one without are worth the same price. They are not. But this perfect scenario never shows up in real life, which is why the argue,nt will rage. You also have to look at motivation of the buyer - some want a collectible Porsche, othes want a car they can track and modify. The motivations are never the same.

Look at old race cars - the first thing owners do is try and re-assemble all the history. Becaus it makes the car more collectible.

Same car, same condition. Car's value is X, as determined by general sales in the same general area (say, Continental U.S.)

The car without records is *still* worth X, physical condition verified by PPI. Car with records is worth X + Y. Car with partial records? Worth X, still. Car with partial records, but important ones detailing rebuild? X + Z, with Z < Y.

Yeah. When there are only five of those cars ever made, the car is no longer a car, it's a piece of history. And the tracing of that history becomes the story.

And if you are a collector, and the purpose of the car is collecting, then yes, all the paperwork is essential.

But that wasn't the original scenario, and a very small subset of these cars in any case. For cars that folks want to own *and drive*, full records from birth don't necessarily indicate a deal-breaker, nor dishonesty or lack of attention to detail on the part of previous owners.

OK. . . . This is much better.
Originally, I understood your first statement to be expressed as X+Y=Z, AND X=Z, where
X=price of Porsche without documentation,
Y=value of documentation
Z=price of Porsche with documentation.

Which is a simple contradiction.

However, what you have expressed above mathmatically seems to reflect what we see in the market place.

The majority sets the market average. On 30-40 year old cars like 911s the majority are no or spotty records. Therefore cars with good or great records are worth more than average. Basically what Eric said without math.

I've seen plenty of cars where Y = "oh cool."

As in 'oh by the way, I have all these records' (after the deal is sealed) and my response is "oh, cool."

There is a subset of folks that feel that recordkeeping is very important, and will pay extra to have that evidence.

There are plenty of us, however, that do not place the same kind of monetary value on that kind of recordkeeping.

:)

I guess I an not a collector type guy, I have had some different and interesting cars and always took good care em.

But as I really never thought about when I was going to sell em(some I had a long time -some not so much) my records were and are somewhat sketchy. Yes it makes good financial sense to keep records but I buy em to own so I guess shame on me.

I have found a lot of hobby guys are sorta like me in this sense - being an informed buyer is the best defense - and what with PPIs and some research I generally have avoided the sows ears.

I don't keep written records.....my memory is all I need. Written records is what screwed the war criminals in WWII.....just sayin'.....

Good thing something did!

Across the pond service records are for the most part a given. You start loosing incremental value if they are not present or incomplete.

I have bought a few 911's in America since 2006 and I must say that not one of the cars had a full service history. When I did ask whether or not the car had one I was looked at with utter disbelief that I would ask such a stupid question and or told a myriad of excuses, the biggest being data protection lol What a load of bovine !

I tend to keep every receipt for every penny I spend on my cars and henceforth if I ever sell the next caretaker will have more piece of mind. Just my two pence.

My record goes back partially to the original owner, roughly 9 years back. Unless it's an accident issue, records probably don't matter after a decade or so because parts have been replaced or worn substantially in that time anyway. A gasket replaced in 2002 has little bearing on its condition today.