Oil Change interval

[carman3]

New owner as of last week of 2011 Boxster S and frist time Porsche owner. Car was a lease car built in February 2011. The first owner purchased the car in April 2011. Car had 2500 miles on it when I purchased it. I had oil and filter change performed as part of deal. This was the first change it had since new. I'm planning on only driving on weekends. Probably 3000 to 4000 a year. Question I have is how often should I change the oil? I'm aware short drives arn't good. I'm also having difficulty keeping the revs down because I love the sound the engine makes and yes I have to admit accelerating hard.

On the PCM service interval it shows the next service is due at 20000 miles. This seems awful long.

So is a yearly change of the oil the correct frequency?

[tonythetarga]

Keep the rev's up! Yes, I would suggest an annual, even with the miles only in the 3-4k range. Congratulations on the purchase and welcome to the board!

[lithium1330]

I do 12mos or 5k miles, whichever comes first. And of course, use synthetic oil only. Though I'm averaging about 7k miles... so, i typically change the oil before I do my annual (2k miles) road trip to the Blue Ridge from S. FL.

[djantlive]

oil is good for 2 years. you don't need to change it yearly. brake fluid should be changed every 2 years. so, you can visit the dealer at least once a year to get inspection if you alternate between these two service alone.

mileage is irrelevant since you don't go over 10k mi in two years. i think 10k miles (which is 1/2 the duration porsche requires), is plenty adequate.

those that do oil change at 3-5k mi is wasting your money / time / resources.

[JFP in PA]

Originally Posted by djantlive

oil is good for 2 years. you don't need to change it yearly. brake fluid should be changed every 2 years. so, you can visit the dealer at least once a year to get inspection if you alternate between these two service alone.

mileage is irrelevant since you don't go over 10k mi in two years. i think 10k miles (which is 1/2 the duration porsche requires), is plenty adequate.

those that do oil change at 3-5k mi is wasting your money / time / resources.

Sorry, but that is completely wrong. Used oil analysis of the oil condition shows that with use, the oil is developing a buildup of combustion by-products, water, and fuel that both break down the oil and additives, as well as forming corrosive (often acidic) deposits that will actually attack engine components. Even with the best full synthetics on the market, these oils are often in bad shape after 5-6K miles, with the critical additive packages drastically depleted and high levels of contaminant build up. This is also why you should never put the car away for the winter with old oil in it.

Ideally, you should be changing your oil when the TBN (total base number) from the used oil analysis shows that additive package in the oil is more than 50% depleted, but that requires actually having the oil tested. We have been collecting UOA's on our customer's cars for years, and regardless of the oil brand you choose, no oil out there is in good shape after one year or 5-6K miles.

With crate motors from the dealer costing nearly $20K these days, changing your oil (and filter) more frequently is hardly a waste of money if you ever saw what happens unnecessarily to one of these M96/97 engines because the oil was not changed often enough, or cheap non synthetics were used. These engines are not tolerant of contaminated or spent oil.

[tcora]

Originally Posted by JFP in PA

Sorry, but that is completely wrong. Used oil analysis of the oil condition shows that with use, the oil is developing a buildup of combustion by-products, water, and fuel that both break down the oil and additives, as well as forming corrosive (often acidic) deposits that will actually attack engine components. Even with the best full synthetics on the market, these oils are often in bad shape after 5-6K miles, with the critical additive packages drastically depleted and high levels of contaminant build up. This is also why you should never put the car away for the winter with old oil in it.

What is this "put the car away" that you refer to?

Ideally, you should be changing your oil when the TBN (total base number) from the used oil analysis shows that additive package in the oil is more than 50% depleted, but that requires actually having the oil tested. We have been collecting UOA's on our customer's cars for years, and regardless of the oil brand you choose, no oil out there is in good shape after one year or 5-6K miles.

I agree. One thing I am unclear on is what a "good" TBN is. I have Blackstone test my oil and, most recent run, with 20,491 miles on (kinda forgot to get to the change at 15k), TBN was 1.2 and their comment was "TBN is still fine at 1.2". Any thoughts or comments on TBN?

With crate motors from the dealer costing nearly $20K these days, changing your oil (and filter) more frequently is hardly a waste of money if you ever saw what happens unnecessarily to one of these M96/97 engines because the oil was not changed often enough, or cheap non synthetics were used. These engines are not tolerant of contaminated or spent oil.

Amen to that - but I will caveat that I have been of the mind that the OEM knows what is right for the engine. Most spec a mileage or a time interval for changes (whichever comes first) and following that with the proper lubricant has worked well for me in a variety of domestic and European cars and motorcycle over the years. The last car I had which had anything like an oil related problem was my 1969 Buick Skylark, for point of reference...

[JFP in PA]

Originally Posted by tcora

What is this "put the car away" that you refer to?


I agree. One thing I am unclear on is what a "good" TBN is. I have Blackstone test my oil and, most recent run, with 20,491 miles on (kinda forgot to get to the change at 15k), TBN was 1.2 and their comment was "TBN is still fine at 1.2". Any thoughts or comments on TBN?



Amen to that - but I will caveat that I have been of the mind that the OEM knows what is right for the engine. Most spec a mileage or a time interval for changes (whichever comes first) and following that with the proper lubricant has worked well for me in a variety of domestic and European cars and motorcycle over the years. The last car I had which had anything like an oil related problem was my 1969 Buick Skylark, for point of reference...

By "putting the car away", I was referring to the large number of these cars that are not used during the winter months. To afford them the best protection, they should be serviced and cleaned up before going into hibernation until the flowers bloom again.

TBN values are relative to a particular brand and weight of oil; to determine the best time to change oil, you need both a value for the virgin oil as well as the used oil for comparison. The 50% value is a rule of thumb based upon the difference between the two, so without knowing the starting value for the oil in question, it is hard to comment.

As for "the OEM knows what right for the engine"; I am sorry, but I could not agree less to that statement. There have been far too many examples of OEM's "recommending" particular oils, oil weights, or oil change intervals; only to subsequently do a complete turnaround when really ugly component failures start to occur. Toyota, BMW, Honda and others have all suffered massive engine failures that were subsequently traced to oil related failures due to the wrong weight oil or too long a service interval. Quite often, the OEM oil weigh, type, and service interval choices are besed upon CAFE ratings or catalytic converter life (the OEM by federal law is on the hook to replace any cat that fails in less than 80,000 miles) than protecting the engine in your car.

Oil properties are a dynamic rather than static measure. The oil manufacturer's tinker with their formulations constantly and change them without any notification, significantly altering how the oil performs. How a given car is driven, and under what weather conditions, alters how the oil performs. This is why years ago we undertook a program to offer customers oil analysis as part of their annual service routines; it allows us to monitor the oils themselves for any shifts due to reformulation, or changes required due to how the particular oil is performing for a given customer. We have seen customer’s with problems like a very noisy engine in a relatively new car (non Porsche) that the dealer could not isolate. The car was running the recommended oil and was way below the recommended 15K change interval (less than 4K miles on the oil). We pulled an oil sample from the car and found it had less than 20% of its original TBN value; the oil was toast. We switched the car to a different weight and brand of oil, and set the service interval for 6-7K. The car has now gone over 50K miles since the problem, and has never had a reoccurrence of the noise issue. The oil weight and service intervals were simply incorrect for this owner.

Oil can actually "talk to you"; listen to what it has to say...........

[mikefocke]

As the owner of 2 new cars within the past year or so, I've actually had to fight the service adviser over my choice of more frequent oil change intervals. 2k initially and 5k rather than their extended 15-20k recommendation which seems more designed to give them a "low maintenance costs" recommendation in reviews and get them through the warranty period and then they'd just as soon have you need a new car or engine.

My Porsches were 1 year, 3k. It doesn't have to be done at a dealer and you can provide parts and oil and just pay for lift time if you want to save. About every other year in low miles use I liked for a P-car mechanic to do a walk around while the oil was draining and see if he saw any signs of my car needing anything done to it. I believe in preventative maintenance, my cars were ultra reliable and very cheap to maintain when judged over a 5 year period.

[mikewood]

50% depletion is a very conservative number supported by the oil industry. Shops also use it, commonly, to validate much more frequent oil changes than oem warranty requires.

ymmv...quite literally

[tcora]

Originally Posted by JFP in PA

By "putting the car away", I was referring to the large number of these cars that are not used during the winter months.

Wow. I guess you failed to see the smiley.

And I see that you like to spout the usual Religious Oil stuff, too.

Got it.

[tcora]

Originally Posted by mikewood

50% depletion is a very conservative number supported by the oil industry. Shops also use it, commonly, to validate much more frequent oil changes than oem warranty requires.

ymmv...quite literally

Yep. I think you nailed it. Heck, I run my motorcycle to (gasp) 5k miles between changes. But then, it only has 118k miles on it, so...

[JFP in PA]

Originally Posted by mikewood

50% depletion is a very conservative number supported by the oil industry. Shops also use it, commonly, to validate much more frequent oil changes than oem warranty requires.

ymmv...quite literally

And some shop's use it to offer their customers options that afford them the best protection for their investment..........

If you ever saw the data on how fast the oil falls out of grade when the TBN drops below 50%, you would understand why the value was selected.

[mikewood]

I have seen extensive research...enough to believe that generalizing is not going to yield "the" answer.

Like I said, ymmv. I'm not necessarily disagreeing with the guidance you give your customers and, if they're happy with the service, it is all good.

Is this the time to discuss the risks in overchanging oil?

[JMatta]

I've always changed my oil at least annually, which equates to around 2500 to 3000 miles...cheap insurance if you ask me. I also installed the LN billet oil filter adapter which allows use of a higher quality filter.

[Fingal]

Mine gets new oil before the winter layup and after each track day. I end up with 3-4 oil changes yearly, with about 5000 miles yearly.

Keep the revs up once up to operating temp. Don't 'lug' the engine. Don't hit the rev limiter with WOT (wide open throttle)

[turboflyer]

I have been doing my 01S yearly regardless of mileage and filter. I run the M1 0-40 euro and also mix two quarts of M1 10-40. Works for me and JFP is right on in my opinion. I dont care how it looks it comes out. I used to do oil analysis but spend the money on oil and inspect my filters on all my vehicles. Congrads. drove a 2012 S but just coild not pull the trigger.

[TheSkilletHead]

I wanted to share an article that someone wrote on another forum a long time ago. He does a GREAT job explaining how and why oil works, and how that impacts things like choosing what weight and change intervals.

FerrariChat.com - FAQ: Motor Oil Articles by Dr. Ali E. Haas (AEHaas) (I don't and never did own a Ferrari - was referred to this a while back and loved it since it does such a great job explaining such an often-misunderstood subject.)

I've read this multiple times over the years and it's a very good read.

Personally I did 2500mi oil change interval before I did my IMS bearing (not relevant to the OP's car) and 5000mi now that I have done it. Those specific numbers are chosen only because they are in the correct mileage range and they line up with my odometer so it's easy to tell when the interval is up.

Best practice: change the oil with your favorite brand of full synthetic 0W-40 or 5W-40 before the car goes in the garage for the winter. If you drive it year round, I would do the oil change right after the last freeze of the year. Oil is affected by both extreme high and low temperatures (although less so for synthetics).

[mikefocke]

Go look up the definition of "severe service" and you'll see that 95% of us drive our cars to that definition. So I start from that interval. I'm cheap, I don't do everything by the book, I don't torque my wheel lugs, don't use Porsche-labeled parts where OEM would do, don't have the dealer do oil changes. I rent a rack and bring my parts and oil.

I do the oil changes even more frequently based on the advice of several people who know the internals of the M96 engines better than the factory, have conducted extensive measurements on hundreds of P-cars and who will never profit a dime from my business. Since I have no warranty, I bear the risk of being wrong and the expense of the preventative I choose.

I've seen JFP's ethics displayed on this forum and others for years. Even though he runs a P-car repair shop, I've never seen him even hint at where it was let alone post it's name. He attempts to keep his on-line help separate from his business which lends additional credibility to his posts expressing an opinion even beyond the historical accuracy and helpfulness of his technical help posts.

[mikewood]

Just to be clear, I wasn't inferring anything about anyone's "ethics" in my comments...which is why I used the word "validate", rather than something like "justify". 50% depletion is a conservative number, but that isn't necessarily a bad thing, if you run a shop and want happy customers.

My point was simply that different starting points, in terms of the oil's specs and additive package, and different use will yield a big difference in the functional life and, literally, ymmv.

[mikefocke]

And why wouldn't I use a conservative figure? Oil change costs per smile/mile driven are trivial. Even on a Porsche. Over a 5 year period and compared only to depreciation, they were 3% of the cost to own. And compared to potential alternatives (like the car my son has sitting outside my house this season that sounds like a '20s tractor because it gets an oil change once a decade)