Thought you might be interested in a Synthetic Oil Life Study I came across:

Interesting highlight when they test Mobil 1:

"Engine wear actually decreases as oil ages. This has also been substantiated in testing conducted by Ford Motor Co. and ConocoPhillips, and reported in SAE Technical Paper 2003-01-3119. What this means is that compulsive oil changers are actually causing more engine wear than the people who let their engine's oil get some age on it.

Topping up the crankcase is a critical component of extended oil change intervals, and frequent filter changes are most likely the key to extreme-length intervals. The cumulative effect of even minor top-ups, let alone a filter change, substantially increases the longevity of the oil.

Based on the results we've got here, we'd recommend 8,000 miles between oil changes on an engine that uses no oil at all, perhaps 10,000 miles on an engine that uses some oil, and 15,000 miles or beyond with a filter change every 5,000 miles. This, of course, isn't any kind of guarantee, and you must evaluate for yourself what your engine requires. One thing we're pretty sure about though: 3,000-mile intervals is a huge waste of resources."

http://neptune.spacebears.com/cars/s.../oil-life.html

 

The oil lasts that long, the filter doesn't, and neither do certain additives in the oil - it's good advice, I've got a VW book from the mid-80s that recommends the same thing with synth oils. I change filter and top up every 3k miles, that takes care of filter clogging issues and the top up renews some of the additives each time, seems to work well. Of course the oldest engine I've done that to I only put 50k miles on, so I don't know of very-long-term effects yet.

Sam

Sam

 

Considering the exhaust temps that these cars can reach and that heat going through the turbo where our oil pumps through, I would wonder how that would affect the oil? It certainly can't do it any good.....leastways I wouldn't think so!

 

Excellent find!!!!!

 

One caveat: When I went from Dino juice to Mobil One, the detergent qualities of the Mobil One REALLY cleaned things up, based on how dark it got in only 1500 miles...I spoke with some folks and they said it was not uncommon for the first pass of synth to really clean out the motor...SO...perhaps AFTER the first go round, you can change less frequently...

 

Mine was SUPER dark after the first change after going Mobil One. It looked like black ink!

 

which is actually not a good thing as this is obviously sludge which went through your engine. Otherwise it just sits somewhere (oil pan).

 

I had a friend in my high-school auto-shop class with a 280XZ-Turbo that had no clue on oil-changes. He had the car for 2-years and drove it 25,000 miles with no oil-changes. When we did the oil-change, it came out thick like tar! Poured in new Mobil-1 and ran it for 5,000 miles before the next change. It came out black, by wasn't anywhere nearly as thick. He's been changing the Mobil-1 every 10,000 miles since then. At our recent reunion, he said the car just turned over 300,000 miles.

 

I' just did a (hopefully sucessful) rod bearing and oilpan gasket job and am about to switch to mobil 1. It's good to know that it'll clean the rest of the sludge out of my engine that wasn't in the oil pan. Hopefully my car won't leak more then it did before I did all that.
On a side note, a friend of mine in high school who knew/knows nothing about car maintinence drove the saturn her dad gave her for years without ever changing the oil. Eventualy the engine blew up and she learned that every now and then cars need more then gas added to them.

 

Yep, a big scam by the oil companies

I remember a test I think on Dateline or 60 minutes for 1 year they tested oils in NYC cabs. So, you can imagine the wear and tear.

They tested standard oils and they changed some every 3K, some 6K, 10K etc. They took the engines to the labs and saw NO effects of extra wear on the longer intervall changes. An this was on cabs that were driven in NYC day after day.

In regards to Syn I ran it once and yea, it got the sludge out, the sludge that was keeping from leaking Went back to non syn and no leaks.

 

To spend the $$ or not to spend the $$......

Car has always been running Mobil 1....since the last owner who kept very good care of it (I bought it in Nov). The 3K mark is up....should I change it or wait to 5K....hmmmm.....

Maybe I should do it myself for once...probably save me money....I paid $85 last time!!! I almost fell over.....

Excuse my ignorance when it comes to this subject....but....how can you do the filter without doing a change? Do you just pop it off....rub some oil around the seal of the new one then just put the new one on? Like I said....sorry if this sounds stupid....

 

Yes, pull the filter, oil the seal and put on the new one, run the car, then top off the oil to replace what was lost from the filter.

Sam

 

IIRC, the Porsche manual it self recommends a longer interval than 3mo/3000miles. I think its 6 months/5000 miles or something like that isn't it?

With the ultra low amount of miles I put on (averaging 2k a year), I change my oil with Mobil 1 mid spring and mid fall.

 

Thanks Sam

Any opinion on what brand filter I should get??

 

With synth oils, the filter becomes more important than the oil, since while the oil will not degrade, the filter will fill up and clog, and start bypassing more and more unfiltered oil.

Sam