A seriously original oil question/discussion

[S2GART]

This is not a question about what oil to not use or use, but does anyone have proof that a particular oil killed or shortened the life of their engine? As anyone reading this knows, everybody has an opinion of what brand/weight and type oil to use and not use, but does anyone have proof that if you don't use say Mobil 1, that your engine won't last as long?

Unless someone stuck with the same oil weight/brand for over a very long period of time, to only then suffer a failure proven to be related to the oil, then all this talk about using Brad Penn/Mobil 1/Valvoline/ etc. is just that......talk.

A lot of people say to use full synthetic because you can extend your oil changes, off setting the cost. Yet the owner's manual for my SC flat out says that the oil change intervals are the same regardless of the type of oil one uses. Others say that one's engine will last longer using synthetic. Since synthetic oil cost literally twice what dino oil cost, so does that mean your engine will literally go twice as long before needing a rebuild....? I am guessing no.

For those who believe the gospel of Porsche about using Mobil1.....that is pure marketing.

Thoughts anyone?

[James Brown]

flat tappet cam wear is well documented in early or classic cars, a quick web search will find many articles about this. There is no reason to not believe that it will happen with our early engines.
the major problem is the oil has changed since Porsche published there requirements and they have not updated oil recommendations.

[Flieger]

Charles Navarro of LN Engineering did testing of engines and saw the wear. Part of how he became an oil guru and was one of the early proponents of Brad Penn.

[Ronnie's.930]

This would not qualify as a "long term" wear test, but a couple of very experienced 930 guys experimented with using Brad Penn, and discovered extreme coking (one led to cam spray bar plugging and cam/rocker damage) - went back to a full synthetic, and no more coking.

[JAR0023]

OP I agree with you to a point. Your SC manual was accurate when written. Porsche has issued tech bulletins changing their recommended oil weights and change intervals.

No doubt our cars need an oil with an additive pack friendly to flat tappet cams. Long time ago there where lots of them. Then the manufacturers all started pulling zinc and phosphorus levels down into the danger zone to extend cat life. Engines died because of this and at some point the oil companies listened to the market place. First it was specialty oils and now most of the bigs have some flavor of oil with the right amounts of zinc and phosphorus.

Synthetic oils hold up better under extreme heat. Do you and I need to run synthetic, not likely a need unless we are racing or live in an extreme hot environment.

I fell off the Mobile 1 bandwagon some time ago, but recently jumped back on it, at least for my wife's car. It's the only M-B approved oil I can buy locally. It's actually pretty cheap and I can get it at W-M. M-B says I can go 15k between oil changes. That's just too long for me without some oil analysis. For about the same cost I can put new oil in at 7500 and feel safe and M-B will never know.

I run Rotella Dino 15-40 in my 911. Good base stock, good additive package with plenty of zinc and phosphorus. Can be bought at just about any FLAPS or truck stop out on the road. My personal experience leads me to believe I burn less between oil changes than with one of the other special grail oils.

My point in all this rambling is there are bad oils out there that will kill your Porsche engine. There are also plenty of good quality oils that work just fine even though they aren't as sexy as the boutique brands. -J

[S2GART]

In trying to keep this from turning into a typical oil thread, I guess my point is that 99% of these recommendations are based on what we all hear from manufactures, when in fact their "recommendations" are driven by marketing arrangements with, for example, Mobil 1. Ferrari has used Shell oil for decades. Hell even the factory workers have the Shell logo on their outfits. So if not for marketing reasons, what is "wrong" with Mobil 1 that Ferrari doesn't "recommend it", but yet it's ok for Porsches.

I understand about the formula changes over the years and what applied in the 70's and 80's may not be so today. Call me a cynic, but I find it suspicious that Mobil 1 is only oil recommended by Porsche, MB, Corvette, Viper, etc. I am the type of person that doesn't take things for just face value. I need to know the "why" and not just because the company says so, when we all very well know that "marketing partnerships" play a very significant factor. Porsche in recent years updated their recommendations for the type of oil for their engines. They now say to use Mobil 1 in their engines dating back to the early-mid 70's. Synthetic oil/Mobil 1 existed back then, yet Porsche didn't use it. As I mentioned Shell was the factory fill for my SC. So synthetic wasn't needed then, but now it is..........?

Often people say, and this too I understand, that due to the tighter manufacturing tolerances of today's engines, synthetic is the better choice. I agree, but back to Porsches recent recommendation to using Mobil 1 for engines from the 70's, how did the tolerances change in the engine.......?

I too use synthetic oil, but only in our Volvo and that is due to the turbo. I want to prevent or lessen the chance of coking in the turbo bearings. My Benzes and 911 get Shell Rotella 15W-40. This is based on the recommended viscosities for the temperatures we get here in New England. Plus it helps that they come in 1 gal jugs.

We all agree that for years the advice for changing one's oil was "Every 3K", but that was perpetuated by the dealerships/quick lube joints. Yet it was considered gospel. That was the classic "tail wagging the dog". So, isn't possible the same holds true with the "only use synthetic/Mobil 1" line of thought/recommendations by the industry.....? I find it funny that people will quickly listen to Porsche saying "now use this oil", yet how many people listen to their recommendation of changing their oil at 15K intervals......? My eyes fell out of my head when I read my owner's manual for the SC and there is is....change the oil every 15K!!! And that was in 1983 using conventional oil.

[silverc4s]

Important to keep in mind that our air/oil cooled engines see higher temps and a wider operating temp range than water cooled engines see.
I always feel more comfortable with synthetic because of the higher operating temp limits they have.

[spuggy]

"synthetic" doesn't necessarily mean what it once did - but the price didn't drop.

Does Porsche still recommend Mobil-1, now it uses a Group III+ base stock? This apparently means it cannot be described as "synthetic" in Germany, as they regard only Group IV (e.g Royal Purple) and Group V (e.g Redline) non-hydrocracked base as "synthetic"...

Elsewhere, they simply re-defined what "synthetic" meant; from the 2000 oil trade rag Lubricants World article Is Your Synthetic Motor Oil Really Synthetic:

Exactly one year after the National Advertising Division (NAD) of the Council of Better Business Bureaus’ ruling in April 1999, upholding Castrol’s position that wax isomerates could be called synthetic, Petro-Canada (Toronto) advertised it would be referring to its very high viscosity index (VHVI) basestocks as a synthetic in the North American market. These products fall into the same API group (Group III) as wax isomerates, but could vary significantly in quality from wax isomerates. This market roar by Petro-Canada has carried a quiet undertone of moves from PAO to VHVI technology by several engine oil marketers.

What does this mean, really? Darned if I know, not my field - and this gets more complicated than picking a cell plan...

I run Rotella T in the 930, cheap, available, good additive pack. It seems to like it.

[S2GART]

Spuggy, your remarks and the attached article just further my point that most of the info that we all started debating about when the oil subject comes up, is based on a bunch of marketing BS.

I too would be interested in what Porsche is recommending in Germany. If they in fact do change their recommendation, just imagine the trouble that would cause Mobil here in the states......

How would newer Porsche owners feel if Porsche starts recommending Shell again. Here it is they had Mobil 1 drilled into their heads as the oil to use and then Porsche in net effect says, "....did we say use Mobil 1 for all those years?, we meant Shell" Which is what they in affect did by recommending Mobil 1 for their cars that had been factory filled with Shell for many years.

[wrinkledpants]

If you were to graph a variety of variables related to engine longevity, and you used a proper weight oil (syn or dino), an oil with high ZDDP, and did average change intervals - I'm almost positive that oil in that signal graph would be well with the confines of the other variables. I've driven just about every car I've owned from Honda Civics to high horse power twin turbo audis to well over 200K miles, and not a single one was even close to needing a rebuild.

Unless you track your car a ton, or live in some extreme environment, just about all the oils recommended here are completely fine, and the difference they have on your motor is going to be negligible compared to how you operate it, maintenance, etc.

Buy a good oil (syn or dino) in the proper weight with a good amount of ZDDP - and stop worrying about it.

There is nothing worse than someone saying "I use XX oil and really like it because it of things that have no correlation or causation to other things, and because a friend said something about YY oil."

I use BP 20W-50 in the summer, and will switch to 10W40 in the winter. Previous owner used Valvoline VR, and he owned the car from 50K miles until 194K miles with track time. BP is easy for me to get, I know it's good oil, and I never loose a wink of sleep wondering about this stuff.

[brads911sc]

More important than brand is right amount of zddp and change interval. Dirty oil is far more detrimental to engine life than the 1200 ppm vs 1300 ppm of two similar oils. Often we read the gurus claim oil as gospel but we don't know other factors such as change interval, etc. these discussions just are not really based in fact.. I use most vr1 because its away to get but have also used gt1 and bp. They all performed similar for me.

[boxster03]

This is not a question about what oil to not use or use

I say we have already gone there - at least it is a new picture

[RSTarga]

Since there have been no technical developments since 1983, I guess you are correct. Just put 30W Shell into that puppy. Let us know how that works.

[S2GART]

I am certainly not saying that there hasn't been advances in oil. I also would never use straight weight oil. I just thought it would be nice to have a discussion about oil without a shouting match over which brand or type to use. I guess this would be in response to the endless advice about oil that is given whenever the question about oil usage is brought up. I was just hoping to bring up some points that perhaps people hadn't considered.

[brads911sc]

Too much kool aide being drank and speculation to have a reasonable discussion....

[boxster03]

Too much kool aide being drank and speculation to have a reasonable discussion....

I think you are missing the point

[Ronnie's.930]

Originally Posted by boxster03

I think you are missing the point

Please explain what the "point" is because I missed it, too (maybe something about how the OP thinks that using synthetic oil in a 911 is a naive waste of money?).

[boxster03]

My "Point" is we have already had a reasonable discussion

Over and Over and Over

If folks don't want to do a search or they would like to start yet one more thread they are free to do so of course

But I think they should be prepared to get mine and other's snarky comments

[brads911sc]

The point boxster is that many recommendations that are in the big thread only take 1/2 the factors into play. And are therefore invalid. I personally like bp and vr1... But maybe the bp car gets changed every 4k miles and maybe the castrol car only got changed every 8k miles. So maybe more frequent changes are the deciding factor... Not the brand. I read every page of that thread and none of the gurus resolve this issue. It's all just preference.
I think the op was just point out the variability in opinion and the lack of any real evidence based statements. My approach is to just choose an oil with at least 1200 ppm. There are 20 on the market. And not get into the syn vs Dino, brand a vs brand b because most of the arguments are bs.

[livi]

I will get back to you the next time I read a double blind randomized study with hundreds of identical engines from the flat tappet era driven from new 100000 miles during the exact same circumstances, then picked apart and scrutinized in every detail.
Until then I bet any reasonably good oil, dino or synth, will do.