yeldogt

My 06 is 2 years or 20k -- I never hit the 20k ... maybe 13k.

My 911 -- Is 15k ...........if memory is correct and two years.

My Jag is 15k and my MB has the FSS -- normally is about 12k.

On my vintage cars I normally go with synthetic because it is good for the two year change interval -- all get low miles.

On our fleet cars we do anywhere between 5.5k and 7.5k using regular oil -- all 5 quart capacity. They run forever.

Use the recommended viscosity.

4k changes on engines holding 9 quarts filled with synthetic?

francars

Every 5k miles on all my cars I have owned. Or once a year if I don't hit the 5k mark.

racer_65

Between 15k to 20K miles. Don't believe in the Jiffy-Lube commercials; look at the maintenance schedule in the owner's manual instead. There's no reason to change synthetic oil any sooner than 10K miles.

medtech

There's plenty of reasons to change synthetic oil sooner than 10K, especially when you are dealing with an engine that's $20-30k to replace, but to each their own...

Slow Guy

I suppose you have some data that shows 10k oil change P!gs have engine failures more frequently than say 5k engines?

RESP

I am still waiting for the "plenty of reasons" to change any oil more frequently.

I believe the lab tests of oil (earlier reply to this post) are likely the only scientific process to determine if any specific oil sample needs replacing.

Other than that, I will take the advice of the manufacture, as backed up by a chemical engineer in a big name oil company. He works on changing oil sands to petroleum products we all use, including oil.

hahnmgh63

I do know what Blackstone labs said about my first oil analysis after 7K and they said it was one of the best looking Cayenne Turbo (they have a database of oil analysis they've done on a variety of models of vehicles) oil changes at the 7K mark which I attribute to the Redline oil that I use. They said stick with the same oil but run it a little longer, maybe 8K~9K for the next oil change and see how the next analysis comes out. I wouldn't run Mobil 1 longer than I run Redline. And I wouldn't purchase a Cayenne used from someone that has. You can go to almost any oil manufaucters website and check their oil certification specs and Mobil 1 barely meets the latest Euro specs and I'm talking about the 0w-40 as the 5w-30 & 10w-30 don't even meet the latest ACEA specs. Redlines HTHS rating for their 5w-40 is 4.6 whearas Mobil 1 0w-40 is 3.6 or 3.7 if I remember correctly. Look at all of the Cayenne engine failures on the forums? Do you attribute them all to manufacturing defects or engineering shortcomings? Maybe time will tell but I feel safer running my less than 10K on the best oil I can get which is cheap insurance. And I would never recommend using a quality oil and changing at 3.5K~5K, yes that is a little excessive but then 15K~20K? When the engine fails I would only blame it on Porsche for the change interval recommendation. And yes, please stay away from Jiffy Lube. I can almost guarantee the synthetic (if it is a synthetic) oil their pumping into your Cayenne doesn't meet the ACEA or Porsche specs.

medtech

I don't really need data on P!gs, since an engine is an engine for the most part. What I do have is common sense. Which tells me that if 10K is the max rated life of an oil, that using it to 20K is BAD, and changing it earlier is better. Exactly how much earlier is certainly up to debate, but it's CHEAP insurance for your engine. I can also look at my oil when I change it and touch the oil. 5K oil is clearer of hard contaminants than 10K oil. Contaminants increase friction. Friction=wear.

Yes, and those lab tests did not recommend pushing past 9K tops.


I suppose both of you believe the manufacturer has nothing but YOUR best interest in mind? And clearly it's NOT true that when they went to 10K intervals, it was more marketing than science, and that actually nothing changed about the cars when they made that move??

Ahhh, ignorance IS BLISS!

deilenberger

If we take this to the logical conclusion that early oil changes protects the engine better (despite data that tells us that longer use isn't causing any harm to the engine) it would seem we should change the oil every time we start the engine. We probably actually should never start the engine. Just change the oil in it continuously. I would sorta make the vehicle valueless for it's intended use, but it would certainly protect the engine. (For those without a sense of humor - this is SARCASM.. with some truth behind it.)

So, where do we make the cutoff without data?

The statement "Ahhh, ignorance IS BLISS!" is certainly true in this case.. I just don't understand someone saving $35 on an oil test and continuing to spend much much more needlessly changing oil.

I'll continue having oil tests done and basing my changes on scientific data. It's the physicist in me that's making me do that.

RESP

deilenberger +1

RESP

medtech -3

medtech

Don,

In my line of work, if I'm wrong people get hurt, die, or their life is cut short. When it comes to Porsches, I cannot afford to buy a new engine. I can afford to change my oil a little more frequently, and change the type of oil based on the age of the engine, expected use, etc. That's the position I'm coming from, sorry if it's too serious.

I don't give data on this subject for 2 main reasons: #1 My data is useless for anyone else but me, given my geographical location, the fuel I use, my driving habits, the oil I use, etc. #2 I expect each reader to find their own data to support which ever opinion appeals to them. It's your car, your money. My opinions are based on my experience over the years reading and talking to knowledgeable people that range from Porsche service techs, engineers that deal specifically with Porsche engine failures, oil experts, and spending way too much darn time on Rennlist.

I agree that sending your oil to Blackstone is better than flying blind. But the actual usefulness of that data is akin to me doing a urinalysis and a CBC (complete blood count) on you and telling you that you are in perfect health. Also, IMO, just because you're Bimmer didn't blow up before you sold it, is not exactly "hard data". Unless you did a complete engine teardown prior to the sale, the true condition of your engine was nothing but a wild guess.

I could care less what anyone on this forum thinks, because we are all privy to enough data and opinions to make informed decisions. I'm not trying to be "right". I would like the casual reader to know a few things about manufacturer's recommendations though;

To the best of my knowledge:

BMW, who started the trend of extended oil changes, did not make that move based on what was best for the life of your engine. It was a marketing ploy because sales were declining in the US. It seems that buyers didn't like paying out the *** for their cars and then also putting out hundreds of dollars for an oil change every 5K. So, BWM rolled out the "free service" for 3 years, deal. Coincidently, they also extended the interval to 10K, which meant that for the average customer they (BMW) were only out 2-3 oil changes.

Porsche sets recommendations based on minimum and average expected life spans of their engines, balanced by customer demands, and market trends. They only warranty an engine to 4 yrs/50k miles, so I will use that as the "minimum" life expectancy from their perspective. We will never know what they consider to be "average" since they will never share that. However, since the maint. manual does not mention anything above 140-160K, I will use that as their average-high, life expectancy (and I think I'm being generous with those numbers). If you are ok with falling somewhere in that range, and you drive only according to the guidelines of you're warranty, then following their "suggested" interval is perfectly fine.

I personally am not ok with my engine lasting to the minimum. If my engine went right now (83K miles on the clock), it would be devastating to me financially. I would like to get 250K out of the car, if I can. (I'm sure Lewis will tell me I have a better chance of winning the lottery)

I have learned from owning a 996, that as an engine wears, tolerances change and things can be lurking (think IMS). At that point the type of oil used, and frequency of oil changes CAN make a difference. Since changing the oil more frequently is about the only thing in my control, and the cost of doing that (myself or at an indy) is peanuts in the big picture of Porsche ownership, I choose to err on the side of caution. (I shoot for 5K, but realistically by the time I get around to doing it, it's somewhere between 6-7k.) Obviously, this will do nothing for me if say, my aluminum block cracks, or if I have a coolant failure, etc, etc.

I will now, respectfully get off my soapbox and shut up...

yeldogt

With all the information available -- non of this is guess work. Do what you want but you're not saving your engine by changing the oil every 5k.

The engines are not failing from extended oil changes.

Divot

Did you have to announce the unrequited love on New Year's Eve?

medtech

I'm just bitter about the backorder of black P!g shirts.