[sasilverbullet]

I think that a big problem for us Porsche owners is transferring the knowledge that is out there for the general car population over to our cars. Porsche engines are not made the same - harder materials, different clearances, etc...



So this translates to the many discussions floating around. Over on the bobistheoilguy site, it's even nuttier because they're all talking about almost every car on the market!



Here's my summary of thoughts - as an engine gets older and the wear makes the clearances greater, a higher weight oil will help it run more efficiently. But with our engines, where's the wear? If you're just driving our cars on the street with an occasional DE, 250,000 miles on our engines is nothing. The word floating around the Porsche mechanics I've talked to is that our engines basically don't hardly wear at all.



So then what do we do? I think that that the 5w-40 or 10w-40 oil is THE way to go for our engines. Amsoil's Euro blend, which is Porsche approved, comes only in 5w-40, so that's why I'm using it. If they had a choice to 10w-40, I would have picked that because of the high heat down here.



Bottom line is that with all these theories we all have - it's hard to quantify who's is right/wrong because of the relatively small number of 968's. For my thinking, I'm including the 87 and up 944 2.5 liter engines because except for the oil squirters, they're basically the same engines we have. So I think that's where we can get some comparisons from.

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[ds968]

at the risk of being slammed for even thinking this <img src="/forum/images/smilies/968/dry.gif" class="smilie" alt="" /> , would there be a problem replacing the M1 15-50 ( I burn a Q about every 1,500 or 2,000 mi. ) with the amsoil 5-40, or redline 10-40, and just run a blend of the two ? Even when you change the oil, why not go half M1 15-50 and half Amsoil 5-40 <img src="/forum/images/smilies/968/huh.gif" class="smilie" alt="" /> ?

Just asking.. <img src="/forum/images/smilies/968/mellow.gif" class="smilie" alt="" />

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[sasilverbullet]

blending of oils is a hot topic over on the bobistheoilguy forum - summary - it's best left to a oil engineer and even they argue about it! <img src="/forum/images/smilies/968/smile.gif" class="smilie" alt="" /> <img src="/forum/images/smilies/968/smile.gif" class="smilie" alt="" />



The recommendation over there is to NOT run ANY blends of anything - we don't have the expertise to know if one small ingredient in one oil will affect the other brand.



suggestion - Why don't you'all wait for my "End of August Report" before making any decisions? I just changed from almost 5 years of running Mobil 1 15w-50 to Amsoil 5w-40 about two weeks ago, I also had no leaks. One month isn't going to change things greatly. Besides driving over 90 miles a day back and forth to work - I'll be doing an all day hard run out in the hill country on Aug 12th.



Sound good? <img src="/forum/images/smilies/968/smile.gif" class="smilie" alt="" />



Many happy smiles...

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[Larry Currie]

I put in the VW fan relay, so my car runs cool with the 15W50 in Alabama weather. Near 100 this week. My seals are also holding up well and at 140+ miles I think I'll stay the course.

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[flash]

the temps i have been watching are not the coolant temps, but rather the oil temps - this is where i have seen a benefit of the 10-40 over the 15-50 - the oil temp has dropped about 5 degrees - the coolant temps have remained the same

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[sasilverbullet]

flash - i was wondering about that - does a thicker viscosity fluid wick away the heat better?

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[flash]

no, thinner wicks better - the trade-off is slightly lower upper temp limit - i've never gotten anywhere near the effective limit of the 10-40 redline though, even when i was using 15-50 mobil 1

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[Rutger Gert-jan]

Hi,



Just to let you know what kind of oil I am using, at the moment it is a fully synthetic 5W40 made by Duckhams...no leaks & problems. But then again I am living in The Netherlands and the temps. are not that high as in some parts of the USA....

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[Cloud9...68]

So it seems that the trend is toward lighter weights, in the 10W40 range, with no reports of problems so far. Has anybody out there who's switched to 5W40 or 10W40 seen any problems, such as more leaks, higher oil consumption, etc.?

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[ds968]

btw, where did you guys hear / read that Mobil 1 is no longer fully synthetic ?

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[flash]

i've been trying to find the memo, but it is all over the web - it's true - they downgraded it from a group 4 to a group 3

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[sasilverbullet]

if you go to www.bobistheoilguy.com and search their forums you can find the announcement/threads on it.

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[ds968]

- looked at that one as well as other various other forums that addressed the topic.. there were several indications in subsequent posts and threads, including a few which copied & posted communications from Mobil ( though not sure how to verify that those were indeed mobil's replies ) that it was no more than a hoax , at first fabricated ( allegedly..) by an amsoil distributor after the Mobil-Castrol "synthetic semantics " lawsuit settlement, which later took on a life of its own and spread like wilfire. stay tuned, I contacted mobil - we'll see ( if ) how they reply.

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[ds968]

received email this morning from mobil :



" The Mobil1 High Mileage motor oil is an addition to the Mobil1 product

line family not a replacement. All Mobil1 motor oils are still 100% and

fully synthetic motor oil formulations.

--

Thank you for choosing ExxonMobil products.

If you need further assistance, please contact ExxonMobil at 1-800-ASK-MOBIL



-Matt Jacob "



that aside, I hear very good things about Redline so I'll probably give that a try on my next change..in spite of the considerably higher price factor <img src="/forum/images/smilies/968/dry.gif" class="smilie" alt="" />

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[flash]

this is potentially VERY ugly for whoever started this - the legal ramifications of such a thing are huge



looks i now need to poke around more to find out what is really going on - i have not been able to find any mobil 1 that says "fully synthetic" at any of the larger chains for quite some time now - could be just a marketing thing i suppose



at any rate, i have been very impressed thusfar with the redline - switching to 10-40 from the mobil 1 15-50 has resulted in higher pressures, lower temps, and a freer spinning engine



by the way, the guy at redline said the same thing about mobil 1 and their formula change, so it seems that if this is a hoax, it is a danged good one - it seems to have gotten to just about everybody

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[sasilverbullet]

If I remember correctly, one of the bizillion posts I read was from a guy that said he actually tested brand new bottles of Mobil 1 and said that chemically, they were not pure synthetic any more, but a blend of dino oil synthetic.



The email from Mobil 1 claiming they are still 100% synthetic is interesting - "All Mobil1 motor oils are still 100% and fully synthetic motor oil formulations." 100% what? "fully snythetic motor oil 'formulations', so what does 'formulations' mean? According to what I read it's like 'natural flavorings' in foods - you can put just about anything in and call it a 'natural flavoring'. So a 'formulation' is just that, a blend of stuff, and as long as it's a small percentage, that small percentage can be dino oils.



Hope that makes things as clear as mud! <img src="/forum/images/smilies/968/smile.gif" class="smilie" alt="" />

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[ds968]

the extended product descriptions on mobil's site would seem to indicate those formulations are normal syn oil additives which the other brands of fully synthetic oils ( redline, amsoil, royal purple, etc ) would also have...each no doubt with a clever marketing campaign as to why their additives mix is better than the next guy's.. may be mobil uses 0.02% additives and amsoil uses 0.015 %.. who knows ?!



at least that's what I interpret



again, I'm going Redline next, so no big deal to me but it just seemed mobil was on the receiving end of some nonsense which for the most part anyway was either not true, or greately exaggerated..

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[oppositelock]

Everyone has their own favorite oil and reasons for using it. Porsche is pretty clear cut about it's oil when our cars were new. Publication WKD 498 021, dated July 27, 1992 states that factory fill for 1993 and newer cars is a fully synthetic Shell oil 5w40. Previous oil was a 10w30 hydrocracked mineral oil. Personally I've been using Redline 5w40 since I bought the car with 23,875 miles on it in 1998. Now has 111,316 mostly highway miles. Was a daily driver unitl December of 2006, now not driven in dead of winter (sand on roads, deicing spray, etc). At 70k miles I had the cam cover off and all looked excellent with chain, pads, etc. Very clean and no varnish issues. Even after a week of sitting, no knocking or variocam issues. Will be doing extensive work this winter along with front seal, which I noticed weeping during last oil change. FWIW, I change oil and filter every 5k. Living in PNW, I do not have the extreme heat issues that some of you guys have, but I do drive it over to Eastern WA on vacation and have no issues. Mitch

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[ds968]

too much hassle searching for Redline at retail outlest around here, so I bought a case of Amsoil 5-40 and will give that a try..

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[kodomokid]

To answer the question earlier about if anyone has changed from a heavier grade oil to a synthetic lighter oil. I have some experience. When I bought the car, the previous owner had been using Castrol GTX dino oil 10w-30 I think. Dino oil in general tends to be a little heavier than its synthetic counterpart. I switched to Lubro Moly Voll-Synthese which is a 5w-40 full synthetic. Instantly the oil leaks that I had became more pronounced. Since then I have had all of my leaks fixed and everything is happy. It may be a cause for concern but I see the good in it. It tells me that the synthetic oil is able to penetrate better. So despite the problems it caused in the beginning, I have a better peace of mind that my engine is being well lubricated. Also I have been using this oil in all of my cars and have been very happy with its durability. 136K on the clock.

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