Which American company breaks ranks in that same regard? you don't really think there is a Restless Leg Syndrome do you? Robert Kline invented that syndrome as a comedy act, I can't stop my leg! All companies screw their customers, in America we call that capitalism.



If what you are saying is they make this statement figuring the car will need replacement sooner, I don't think I can agree with that.

What I am saying is that I trust Porsche NA alot less than Lexus US.

:D

I can't argue with that, Saab has been unbelievable to my dad , the Porsche dealer in my hood is greedy and indifferent. My dad's car is in the shop they toss him the keys to a brand new drop top turbo with about 4k on the clock. It's smart business, he has repurchased there because of it, Porsche doesn't seem to care.

I am sure the 12,000 mile interval for 986 cars works great for the typical Boxster owner who never exceeds 4,000 RPM and spends most of the time cruising up and down the interstate.

For those of us that, use our cars it's a different story.

Oil threads usually never reach agreement.

I would say that I have never seen a used oil analysis that would support an interval near 20K on any Porsche.

Just my experience and who would want to risk this on a car that you are going to keep?

These engines are expensive.

:)

I just find the possibility that Porsche would recommend an interval which results in the engine running on trashed oil fascinating. If the 20k oil is inadequate, by virtue of failing objective, widely accepted test levels, it blows my mind that the factory would recommend it. Awaiting a 20k test eagerly. There's bound to be many here following the factory recs, or?

I've reported this before so I'll give the short version. When Porsche tested the 996 turbo in the US, they drove it 100,000 miles in the LA area on 87 Octane gas and did not change the oil at all, just added it as needed. When the motor was torn down, it was still within new tolerances. This was presented as a tech session at a Porsche Parade.

I would love to see the data on that. I can tell you that ANY oil is shot at 20K miles and the 100K is a joke in my experience. Now, if the car was using a qt of oil per say 1000 miles, then, well you get the picture.

If you can provide details on this story, I would appreciate it.

Here's what I know. 03 Sliverado 8.1 lt gas 105,000 miles I use 5w30 mobile 1. haven't changed oil in 3 years add 1-2 qts. between computer recommened changes, new filter every other time. feels just as fresh as new. Truck gets used for every thing short drives, trailering, highway. it's my own little experiment.

When I owned BMWs, I always wondered if they tauted longer than average oil change intervals because so many of their cars had BMW paid maintenance packages. You would figure one oil change per year per car is much less costly than two.

Just a thought.

I change my oil once a year in the summer at about 7k mile interval.

Obviously owners are free to do as they please with regard to oil changes. My oil reports don't support the notion of running the oil longer than 10k with my driving.

The factory only cares about you getting through the warranty period. Once you're out of that period they couldn't care less how long your engine lasts because they're not paying the bill for replacement - you are.

I think the distinction that has not been made so far is wear vs. engine melt down.

I would never suggest that the Boxster IMS issue is related to dirty lubrication. We know that is a design issue.

Now, if someone wants to reduce nornal wear on an engines internals (for whatever reason) they should care about the quality of the oil, as that is a major factor involved in wear, along with the intrinsic engine design.

Again, used oil analysis does not lie. If even the best synthetics are shot north of 10K miles, these oils cannot be doing their job and extra wear will result.

The only issue is whether anyone cares. Porsche would not be concerned because this wear would not generate any issues during the warranty period.

However, the flip of the coin is, if you Porsche engine blows up under warranty, you can BET they will be checking your maint. history to see if you changed the oil according to their rec.

:)

Quick story... once I bought a dodge van with 96k miles. Drove fine, oil looked fine on dipstick. Drove for a couple months, got sick of top-heavy feeling and sold it. New owner drove for a couple months then it threw a rod! Mechanic found 1" of sludge in the oil pan and said the oil had probably never been changed! Everything seemed fine but that was a disaster waiting to happen!

I trust the wear shown on used oil analyses and even more so those folks that have torn into engines and seen the wear and sludge buildup. There is a tremendous amount of data out there and most everyone says that earlier is better. I hope the experiment doesn't hold any surprises down the road. You are a brave man.

A UOI on that Silverado would undoubtedly show lots of moisture in the oil as well as insolubules (i.e. sludge). I would never do that to one of my vehicles, even my beater 190,000 mile Nissan. To each their own.

I changed my 0w-40 Mobil 1 and factory filter yesterday at 17.5 months and 11,232 since the last change.

I'm sending in a sample for analysis including a TBN study.

I will post the results when available.

Paul, did you need to add any oil during the 17.5 months?

None, it never left the "full" mark. Not bad for a 7 year old car with 67,700 miles that's driven harder than most.

Heres what I got on my last:

The results are in. As I've said before driving a Porsche harder than most doesn't seem to hurt it. I've been flooring and shifting near redline every Porsche I've owned since 1974 without an engine failure. I take my cars on 5000 mile 3 week vacations.

So much for Porsche not knowing anything, the recommendation below is to change my oil even later!

http://i33.photobucket.com/albums/d6...sisApr2008.jpg

Your Porshe is wearing better than most.

notice that line.

And, 11K is not 20K/

:)