Maverick1

The reason I'm asking is that after reading many threads on many different forums and looking for used Porsches, it seems like people feel that 50,000 or even 30,000 miles on a Porsche is a lot of miles.
Speaking to some dealers on cars with over 30K their reaction is, well you have to understand that car is priced lower "because it has a lot of miles", what's up with that.
30,000 is not a lot of miles, not in my book.
I purchased a 1988 Honda civic hatchback base model, 5 speed, not even a CX or DX this was bare bones, didn't even come with a stereo for around $9,600.
I then proceeded to put on over 330,000 miles on it over the almost 20 years I owned it, and the engine never died, it was the rest of the car that died.
In many threads regarding Porsche vehicles when someone hits 100,000 miles it seems like some kind of miracle has happened, like people are surprised.
Am I wrong in assuming that if I spend over $100K on a Porsche that the car should be able to rack up 200,000 trouble free miles?
I currently have a 2005 Porsche Boxster with over 50,000K and after my experience with my Honda, I was assuming I could easily get another 100,000 trouble free miles from the drivetrain.
A Porsche engine should be more robust than a Honda 4 banger, shouldn't it.
I guess what I'm trying to figure out is what is the lifespan of a properly maintained Porsche engine?

stefang

Any high performance engine is going to be more stressed than a civic powerplant and is not likely to last 300000 miles. 30k miles on a Porsche is "a lot" because people generally don't drive them much, not because it's about to blow up.
Different generations of Porsche engines have different potential problems, so generalizations about lifespans are difficult. Your generation engine has well known potential issues, but there's definitely Boxsters out there with >100k miles. So just drive the hell out of the thing and don't worry about it.

alexb76

There's always more stress on a higher performance engine than basic powerplants. They are just designed to work in the uppper limits.

However, 30,000 miles is NOT high at all, in terms of engine life. BUT, as Porsche buyers are usually the type that own multiple cars, only drive Porsches in good weather, and many do NOT drive them to keep their value higher, they end up having low milage in general... hence a 30K newer 911 may be on the higher end of milage across the cars available for sale.

You can see many cars around this forum at 100K miles or so with no issues.

To sum up, 30K miles is NOT a lot of miles on a Porsche, and if you found one that has been maintained right and they offer a discount for the *higher* miles, BUY IT, it will run fine for many years to come!

Hella-Buggin'

I'm approaching 60k on my car and I can't see a light at the end of the tunnel.
At my DE event, granted yellow beginner group, I was getting spanked by a guy in an 86 Carrera with 179k on the original engine. Sure, it leaked a little oil and maybe lost a few ponies along the way but this guy still had smiles around every corner.

Macster

"I guess what I'm trying to figure out is what is the lifespan of a properly maintained Porsche engine?"

No one can say. It is a fact of life that some engines experience a brief life span (relatively speaking) due to some mechanical failure that has nothing to do with how the engine was maintained.

My info is that an engine has 10K hours run time of life. This is some kind of average number. To put this into miles over a span of time a car averages around 30mph, thus this works out to 300,000 miles.

Thus my expectation was (and this has been the same with every car I have bought) when I bought my Porsche Boxster that the engine would last 300,000 miles. (At over 263K miles that 300K miles mark is getting close.)

The engine is only a strong as its weakest part and there are a lot parts in engine any of which should it fail could take out the engine.

I have to point out that in some cases of catastrophic engine failure the failure came at less than 50K miles. A problem is that often these engines are not used all that much - the cars are placed on some kind of pedestal -- and a failure occurs outside of a warranty that expired on time. It is miles (run time) that brings forth any issues with an engine/car not time spent sitting around.

The only way to know the life of a properly maintained Porsche engine is to buy a Porsche, either a new one, or a used one, and if used in good condition with a good history of proper treatment/care/servicing and properly maintain the engine, the entire car, and find out for yourself.

I'm working on two Porsche engine lifetime experiments: My 02 Boxster now with over 263K miles on its engine and my 03 Turbo with over 103K miles on its engine.

Edgy01

I've been driving Porsches longer than most of you have been alive and find that the older engines (pre-water) could easily run 150,000 miles before you needed to do something to them, while the water boxers should do even better. There's nothing 'fragile' about a boxer engine--air or water cooled. Porsche engineering provides for a robust mechanical marvel, but you must not compare it to a Honda. No Honda gets nearly 400 HP out of 3.8 liters of displacement--reliably.

There were a few years of really bad Porsche motors, e.g., the days of thermal reactors and early emissions challenges. Year to avoid: 77.

Dr. No

300k

wwest

Downshifts that result in engine overspeeds might be the major difference. Dangerous in a FWD vehicle, not so much, other than engine damage, for RWD.

MJBird993

No.

The key is "properly maintained". If properly maintained, it should last as long if not longer than any Honda.

Mumbles

Have to agree about the durability of the Porsche engine, I think regular driving of the car is better than once every two weeks or so.

Honda does make a great engine especially the vtec line with next to no problems with millions produced. I sold my stock Honda s2000 with a 2.2L engine producing 237 hp 107 per L compared to 105 per L for 3.8 @ 400hp

Linnm

My 1996 C4S did 110,000 miles before the car was totaled in an accident recently. Sure with that kind of miles it seemed like I was doing tires every year or two (got 10--13,000 on rears, about 2X on fronts), I kept maintenance up to requirements, including plugs, oil, brake fluid, brakes, etc. It never left me stranded. It went away with the space saver tire never having been on the ground.

I hope my 2009 Carrera, .2 does as well. Early signs are encouraging.

Fred R. C4S

Some insight on target engine life for the design of an engine...At the big yellow tractor company we design engines for a long, but targeted lifespan. Nothing lasts forever, but customer expectation drives the economics of engine life vs cost. A large mining truck will have an economic life span of about 10 years. During that lifespan, all the major and minor components will be scheduled for replacement several times. Customers like to think of life as measured in operating hours, but when it comes to engines, life is measured by the total amount of fuel burned.

After the engine has burned 125,000 gallons of fuel, it is "worn out", and due for a complete rebuild. How many hours this takes depends upon how fast you burn the fuel, or more simply, how hard you work the engine. A good analogy is a simple battery. It starts with a full charge, and will last for as long as it takes you to use the charge up.

The actual life of a particular engine will vary from the fuel burn target if there are unexpected internal failures or poor maintenance. You simply cannot spin a 911 engine to 9,000 rpm and expect it to meet the target. You've stretched the rod bolts, and a major rod / engine failure is likely in the cards.

History has shown that well maintained and not abused 911 engines can easily reach 100,000 miles. History has also shown that nearly every iteration of 911 engine has had some particular Achille's heel. Soft valve guides, cam chain rails, IMS bearings are just a few that come to mind. But the overall failure rate of these is quite low. I do think life expectancy has reduced over the years as Porsche has taken cost out of the design. Some of that has been offset by better materials and manufacturing processes.

At the end of the day, the current 997.2 engine has thus far proven to be quite reliable. But it's still early in its life and not many examples have had the chance to prove a 100,000 life. The only engine that I have doubts about long term reliability is the M96. I think Porsche stepped over the line with that one, and have since pulled back.

Just one old engineer's opinion

Maverick1

Thanks for your opinions.
I have a technical, engineering type of question.
I've been told and read that most engine wear occurs during the start up of the engine, due to the oil on the cylinder walls having dropped down into the oil pan, resulting in dry starts.
So, with inline 4 and 6 cylinder and V type engines I can visualize the engine and the oil dripping off the cylinder walls down into the oil pan due to gravity.
However, with a boxer engine since the cylinders are in a horizontal position, even with gravity working, the oil on the cylinder walls would not completely drain off but would migrate to the bottom half of the cylinder walls so dry starts should be less with a boxer engine I think.
Does this make any sense to you?
How much wear would an engine pre-oiling system prevent if any???

Fred R. C4S

Pre-oiling does not put engine oil on the cylinder walls. However it does help by produce an oil film on the main bearings before the crank starts to turn. In theory this would reduce bearing wear at startup.

Many mining machine owners have tried to use pre-oiling to extend engine life. There is a company that makes a pre oiler that is part of the starter motor. It caused more problems than it prevented due to the poor reliability of the pre oiler section. So the machine was in the shop to have this repaired instead of working on the haul road moving ore to the processor.

For an automotive application, a pre oiler is just a waste and needless extra complexity.

Macster

This truism that most wear occurs at engine start has been around a long time, and I believe based on empirical evidence false or at least is not the biggest baddest factor in engine wear.

I mean look around you. Every car, not only Porsches, have engines all of which get started all the time at all temps and there doesn't seem to be a significant number of worn out engines.

(How many times do you think my 02 Boxster's engine has been started over the last 11 years and 263K miles?)

Barring a car that sees so little use that the engine sits for a long period of time (no real idea of what in this context would be a long period of time) between engine starts I say this wear on cold start just isn't a real factor in modern engine longevity.

What I believe is more likely the factor is engine engine wear which is chemical in nature.

It is the constant exposure by the ever increasing levels of acidity in the engine oil to the engine components that is the real wear culprit.

This acidity attacks every metal surface and seal and gasket that is contact with the engine oil.

Now some corrosion on the inner walls of an engine block is not going to be an engine killer.

But having oil lay stagnant in the bearing voids, in the/around the rings, piston/cylinders, lay stagnant in the zero lash lifters, in the chain tensioners, and other places will over time see these areas affected by the corrosive action of the oil, that is the water in the oil that is acidic.

Remember that as soon as the engine stops running oil begins to stratify. Water and oil do not remain mixed so a thin layer of corrosive water begins to form.

In my opinion then it is clear that keeping this acid build up down is paramount.

Sure modern oils come with additives to neutralize the acids that naturally form in engine oil, but there is a limit. What works for one owner and his usage of his vehicle may not work for another owner and his different usage of his vehicle.

One way is to avoid using the car in such a way that leads to a build up of water/unburned gasoline in the engine oil. This is not as easy as it might appear for reasons I won't cover here.

Another course of action is to assume this acid builds up regardless of how the car is driven and periodically remove the oil with its load of acid. This is fewer words is change the oil/filter.

As I have mentioned uncounted times reasonable oil/filter service intervals is about the best thing an owner can do to prolong the life of the engine.

Second best thing, and it really is tied with reasonable oil/filter service intervals, and that is give/treat the engine with a reasonable amount of mechanical empathy.