[Eberhard]

Let's start with the popular Mobil i as an example. From the time it was first introduced - it never was a pure synthetic oil.

Only the base stock in Mobil 1 motor oil was true 100% synthetic (polyalphaolefins "PAO" and ester, Group IV and V base stock). However the 20% or so additives used mineral base oil. I think there was a footnote on the Mobil 1 bottle before. So with the additives, Mobil 1 was never a 100% synthetic oil with this additive content. Today, the recommended BMW LL 01 viscosity Mobil i is a Tri-Synthetic Series motor oil with even less synthetic base stock.

The reason? Castrol changed its Syntec "synthetic" oil formulation by using Group III base stock without reducing the "synthetic" price premium (the cost to get Group III hydrocracked base stock is about half of what it takes to produce the Group IV or V base stock).

The old news is that Mobil sued Castrol for naming their refined mineral oil as "synthetic" but lost in the court. That is why Castrol is still calling its Syntec "synthetic" even though it uses super refined mineral oil. In fact, most "synthetic" oils use the Group III base stocks. Group III base stock is actually very good. It performs quite similar to the Group IV or V base stock except it has a higher pour point and a lower flash point.

Now back to Mobil
1. Profit drives the way any company behaves. Since Castrol (and everyone else) can maximize its profit by using a less expensive base stock and sell it as "synthetic" - then why not Mobil? There comes the Mobil 1 Tri-Synthetic Series of motor oils. Here is the product description from the Mobil Website:

"The Mobil 1 Tri-Synthetic Series motor oils are manufactured from 100% synthetic base stocks. These include polyalphaolefins (PAO) and two other Mobil synthetic fluids that make up the Tri-Synthetic formula. These synthetic base fluids are pure chemicals, which do not contain the impurities or waxes inherent in conventional mineral oils". Yes, the PAO base stock is truly "synthetic" and is of the Group IV or V base stock. It has no mineral content in it. So what are the "two other Mobil synthetic fluids that Mobil says, "do not contain the impurities or waxes inherent in conventional mineral oil". Hydrocracking removes all these impurities or waxes from conventional mineral oil to produce a super pure Group III base stock. That is one of the other two (or both) Mobil is talking about here . However, either or both are made from conventional mineral oil, not like the PAO stock, which is truly "synthetic.

So when you buy a "Synthetic" oil - chances are you are paying for mostly (if not all) highly refined "dino" oil.

Any SAE/API type engineers in the group? I did quite a few searches but didn't get much on "synthetic" oil composition or objective recommendations.

Though I am expecting some repercussions on this post, I would hope they are constructive and still recommend an oil with a high synthetic content due to the high oil temperatures a turbocharged engine produces, one of the more significant advantages a true "synthetic" would odder in a hogh operatint temperature turbocharged engine. The other major advantage is increased shear strength and longer intervals between changes.

Eberhard

PS: After the 1500 mile oil change - I may run some of the better oils with a high true "synthetic" content if I can find one that is proven, available, and costs less than single malt Scotch. After that I will change the oil at six month intervals or 7500 miles, whichever comes first (OEM filter as well).

Note I have had previous and costly disasters using RedLine "synthetic" gear oil in manual transmissions and limited slip differentials - loosing many. The formulation has since been changed - after I lost thousands of USD replacing syncro rings and clutch packs. Now the only RedLine product is WaterWetter and distilled water for coolant on racetracks where a glycol spill is a hazard.

And I may well use a European product - some of which have a very high true "synthetic" content. But note too that I have had good luck with Mobil 1 in large displacement six cylinder air-cooled motorcycle engines where cylinder head and oil temperatures (especially in traffic or on the dyno) were astonishing. Readily available, I may just go with one of the Mobil 'synthetics" in the new 335i - with the right viscosity and change intervals - it should perform very well for street use.

http://en.wikipedia.org/wiki/Synthetic_oil

[6Zylinder]

+1 And for all these reasons you mentioned, I use Red Line synthetics which is made from Polyol Ester base stocks.

[Serjames]

Not sure I understand the point you are trying to make ? I can understand that there seems to be some "license" here over the description of the oils, but how is this affecting the running of your car ?

Sorry not trying to be difficult sounds like you've really done your research

SJ

[toofasttooslow]

All big brand oils essentially sell snake oil and label it synthetic. The only truely good synthetic brand I've found that's commercially available here is Amsoil.

I've been using Castrol 5W 30 unfortunately for this car out of respect for the BMW engineers who presumably know what they are doing. I've come to the realization however (after burning a full quart after 2500 miles) that the Castrol sucks. My next change will definitely be done with the Amsoil 0W30.

Shame on me for even going back to Castrol. I used to use it in my Supra years ago, and everytime I used it the car ran like ass. I finally gave up on synthetics and went back to a high quality non-synthetic oil and just changed it much more often. Low and behold the car ran smoother, less lifter noise and less heat.

[sambonator]

So, is this like, you thought you were buying diamonds and you got cubic zirconia?

[lawdude]

So what does Bob the Oil Guy say about it?

[6Zylinder]

Pretty much the same.

[lawdude]

Originally Posted by 6Zylinder

Pretty much the same.

Link?

[Gen_E92]

For those in NA, if you want a true fully synthetic oil, forget anything made in NA and just get those made in Europe. For example, I got the Elf Solaris 5W30 which is LL-04 rated and made in France.

[Nebo335]

Originally Posted by Gen_E92

For those in NA, if you want a true fully synthetic oil, forget anything made in NA and just get those made in Europe. For example, I got the Elf Solaris 5W30 which is LL-04 rated and made in France.

Any other European oils you can suggest, or is this the be all and end all?

[DrGP]

Never the less , the original Mobil 1 oil is pretty damn good. Originally advertised as a 25k mile oil change interval. But anyone leaving the oil in that long is crazy. IF you are changing so called synthetic oil on a 5k-7k interval it really doesn't matter if it is 100% synthetic not. If you intend to leave the oil in for a full year or 15K, a real full synthetic oil would be recommended. But I don't think ANY oil should be left in the engine that long

[remydlc]

so what's the recommended oil? I planned to change the oil this week , I have almost 9.5k miles without changing it , but at least a put a quater of Castrol 5w30 hoping that would help.

I was being lazy to take the piggy back out and take it for an oil change at the dealership shop, but instead i am taking it to some other shop.

[RMRC]

I use German Castrol Edge 0w30, a true group IV and V oil. You can get it at AutoZone for $6.19/quart. If you try it make sure it says "Made in Germany" on the back of the bottle.

[6Zylinder]

Originally Posted by lawdude

Link?

[lawdude]

Originally Posted by 6Zylinder

I guess you couldn't find it either.

[RMRC]

Originally Posted by lawdude

I guess you couldn't find it either.

Is this what you guys are looking for? Relates more to GC but a lot of M1 discussion and facts. A lot of reading here...

http://www.bobistheoilguy.com/forums...643#Post718643

[6Zylinder]

Originally Posted by lawdude

I guess you couldn't find it either.

Honsetly I mixed it up with an article I read on a german board. It was the same what "Eberhard" posted. I can't find it on bobistheoilguy....

[6Zylinder]

Hey "reb03" I saw your post on the bobis...... forum. You're concerned about heat, why don't you try Red Line?

[RMRC]

Originally Posted by 6Zylinder

Hey "reb03" I saw your post on the bobis...... forum. You're concerned about heat, why don't you try Red Line?

For track days I plan to try several oils including Redline 5w40. But for every day I like the German Castrol 0w30. We'll see what my next UOA looks like.

[BOOST3D]

is royal purple a good oil?

[Former_Boosted_IS]

I personally will use Castrol for two reasons, the BMW manual recommends it and my former supra tuner called it the best oil he ever tested in a boosted engine. The guy has 8 second supras and I think that is enough reason to use it as any.

[Neema]

Originally Posted by hayx1989

is royal purple a good oil?

yes, deffinately

I only recomend Motul 300v, Castrol Edge, and Shell Helix...............do your research before you ask me why. Just to let you know, any of these three will cost you about $130-$180........they're about $20-30 per liter or so.