20K service, good for the car or Porsche

Guest · Mar 6, 2006

I've got my lovely new 987S, which I might keep for a long while. This got me to considering how often to change the oil. On the 20K regime it's clearly 20k or 2 years. Now, whilst I think that the American 3000 mile oil change is bonkers, there does seem to be some scientific work which shows that Mobil 1 deteriorates beyond 8,000 miles. It does seem to work within tolerance until 15,000 but then it looks as though it would be better to swap to some new oil. Indeed, mobil only used to recommend the oil up to 15K miles.

So my question is, for a balance of long engine life and saving the planet what should the best interval be? 8K, to where it's perfect or 15k to where it's off song? Or should I believe Porsche has no ulterior motive and 20k is just as good.

Why do Porsche say 20k, is the engine miraculously easy on oil and wear resistant. Or does it fit nicely with the company car crowd, with the added benefit of worn engines meaning more parts and new car sales.

What's best to get the engine to live for 300,000 miles?

cheers.

waspe · Mar 7, 2006

This has been addressed on a number of previous posts, and I think its safe to say that there is no concensus view. Therefore, you should do what feels right for you. I have a new 987S, which I also dearly love, and will be changing the oil annually. I don't believe Porsche would recommend a service interval that is not optimal, however, I just want to "baby" the car.

On a related point, I needed an oil top up, took it to the dealer, and they added Castrol 5W-30 synthetic, into a sump (I know its dry) full of Mobil 1 0W-40. Does anyone have a view on whether this was wise?

daro911 · Mar 7, 2006

ORIGINAL: waspe

On a related point, I needed an oil top up, took it to the dealer, and they added Castrol 5W-30 synthetic, into a sump (I know its dry) full of Mobil 1 0W-40. Does anyone have a view on whether this was wise?

Wise or not why didn't you just buy Mobil 1 and top it up yourself. At least you would have known the right oil was used and the procedure would have been done correctly. I've lost count of the times OPC's have under or over filled my sump since joining the Porsche experience circa 1978![

]

oceancarrera
For those who are members of CostCo, Mobil1 0w-40 is regularly stocked at just £24 per 4L (includes VAT)
http://www.porscheclubgbforum.com/tm.asp?m=185678&mpage=1&key=&#185678

THX911 · Mar 7, 2006

Maybe the clever business heads at Porsche forced the engineers to make the first service to coincide with the end of UK warranty? [8|]

Guest · Mar 7, 2006

Just had my car serviced, just under the yearly marker post and only 8k miles done since last oil change. The difference was quite noticeable....

I do however try to change the oil - Mobil1 - every 8-10k, just happened that this coincided with the service interval.

In response to the first post... I think the question should be, how do you drive the vehicle? This 'should' stipulate when the oil should be changed... Porsches Figures are bias towards good (affordable) motoring, whilst keeping the vehicle replacement cycle in mind. Lets remember that most car manfacturers make only a very small profit on car sales and rely on the servicing aspect to keep going.... So they ensure that the recommended approach is good for both parties.

Mark_Bennett · Mar 7, 2006

ORIGINAL: waspe

On a related point, I needed an oil top up, took it to the dealer, and they added Castrol 5W-30 synthetic, into a sump (I know its dry) full of Mobil 1 0W-40. Does anyone have a view on whether this was wise?

A couple of points here.

1. Probably won't do any harm - although it makes a mockery of Porsche's partnership with Mobil, and the oil companies advice not to mix brands... (but they would say that wouldn't they?)
2. I'm afraid it is not a dry sump - not in the true sense. It is more Porsche marketing speak - I believe they have called it in the past a "Semi-dry integrated sump", which is just tosh.

From Porsche's website:
Oil is extracted from each bank of cylinders by a dedicated oil scavenge pump. After de-foaming, it flows from the main crankshaft bearings directly into the oil reservoir. From here, it is pumped to the lubrication points and begins the cycle once more. Originally developed for racing use, this proprietary Porsche technology ensures consistent lubrication in even the most extreme high-speed corners.

A good explaination of wet/dry sump here:
http://en.wikipedia.org/wiki/Dry_sump