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Old 09-09-2005, 09:49 AM   #4
SD987
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Join Date: Jun 2005
Location: San Diego, California
Posts: 874
Old habits die hard...I too am from the school of 3000 mile oil changes but I think this approach may not be necessary in all situations.

1. If Porsche engineers felt that following a more rigorous oil change procedure would be better, they would probably recommend it. There's no financial incentive for them to increase the interval, but there certainly is for the them to decrease it, e.g. an increase in dealer service visits, improving the longetivity of the engine, thereby reducing engine failures and warrantee replacements and indirectly improving the company's reputation for reliability. If they set the intervaly at 10 or 12 thousand miles, people would still say..."wow, that's a long time"...but instead, they set it at 20,000. There's probably a great deal of thought and testing behind it.

2. Not many cars run synthetic from the get-go. I don't think that many boarders are experts on engine oil viscosity but I think we can all agree that synthetic does the job longer, it's just a question of how much longer (see point 1). We've all heard about big rig trucks that run synthetic with amazingly long intervals, and while we're not driving semis, synthetic oil is pretty amazing stuff. Conversely, I'm highly skeptical of "seasoned" pros who drain the oil and say..."wow, that's been in too long". Used oil looks alot like used oil, and irregularity such as discolored traces are indicative of other engine problems not necessarily the amount of time it's been put in service.

3. Porsche engines hold/require an amount of oil greater than the amount normally held by engines of similar displacements. Whether this translates into better lubrication is beyond my knowledge, but it certainly would infer it.

4. I think that how one drives more directly factors into oil life than months/miles elapsed. For example; driving at high revs, climate, dusty conditions, running the air conditioner alot are all variables that are difficult to quantify but definitely have an impact. Auto manufacturers attempt to determine an "average" amount of engine use (or abuse) and appropriate service intervals. Your experience will obviously vary based on your conditions, but I assume that manufacturers err in the direction of caution. Quite possibly the oil interval under ideal conditions could even be longer than it is set at.

5. IMHO people misunderstand break-in. They attribute improved "smoothness" to an "eroding" effect between moving parts, when I believe it's more accurately attributed to a "settling" effect of seals etc. Keeping in mind that the engine oil actually serves as a lubricating film that keeps parts from coming into contact with each other. The expectation that changing the oil after 1000 miles will rid the oil of particles that have eroded is unrealistic in that such particles would actually be highly undesirable, not to mention unlikely after such a short period.

But...changing the oil is only @125.00 or thereabouts, and as they say it's your money. If it gives you peace of mind, then that's a pretty small price to pay. I personally plan to get my book stamped on schedule.
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