Originally posted by Pepse:
OK Jim, you say Valvo and Pennz are not as good as Mobil 1. Could you elaborate as to why you think that? Altho there ain't nothing on sale around here that I am aware of the cheapest price I seen for synthetic is $4.48 a qt for "Q" (AKA Quaker State) and $4.52 for Pennzoil. Mobil 1 is $4.99.

One thing I don't quite unnerstand is it was stated that with synthetic I could use 0W40. HMMMM, that makes me wonder about what is synthetic really. I mean with regular oil I should (and do) use 5W30, but with sythetic I can use 0W40; meaning that since sythetic is artificial it is OK to go higher (40W), than to stay at 30W. Interesting.

Elraido states it could be my injectors; so that adds another log on the fire as to what might be wrong. For now I am going to NOT make any rash judgments until I change the oil and see if anything else makes noise.

I decided to wait until Friday or Saturday to get oil. In this way I think I will have a good answer as to what to purchase.

Later Pepse.




It's in the base stocks, or the base oil used for blending. The oil industry breaks down base stocks into 5 different catagories. Groups I and II are slightly different grades of dino oil that have been refined (seperated, cleaned) from ordinary crude oil. Up until a few years ago, all conventional oils were group I or II.

Group III goes through a different cleaning process, using water. Sometimes called "hydro-cracked". Some sort of molicular structure alteration takes place. Actually this is sometimes referred to group II+ as well as group III, depending on who is doing the processing. This was pioneered by Chevron, and is used by them and their other brand, Texaco. Chevron calls it "iso-syn", but sells it as conventional oil. Conoco has licensed the process from Chevron and uses it on Conoco and it's other brands, Union 76, Phillips, and Kendall. Conoco also supplies it for Motorcraft. Conoco calls it "clear base". Conoco refers to it as "synthetic blend", so it probablly is a group II and group II+ or group III blend. Penzoil is also licensed for the process. Pennzoil calls it "pure base". I don't know which of their other brands also use it (Quaker State and Wolf's Head) Pennzoil is currently owned by Shell. I don't know wht process or blending stocks Shell uses. Mobil (and it's partner Exxon) also use a similar if not the same process. Mobil is the biggest single supplier of group III blending stocks for other oil companies. Mobil does not consider group III to be a synthetic.

Group IV is also known as PAO (or POA, I get it mixed up). It is most definitely a synthetic process. At one time, most every oil company that had a synthetic oil use this. Castrol determined that group III could be called synthetic and reformulated their synthetic to use group III base stocks. As an aside, you cannot judge an oil purely on the base stock used. The additive package is also critical so that how the oil actually performs overall is really the most important thing of all. Mobil sued Castrol over what they thought was misleading to the consumer, and Mobil lost. Castrol Syntec is usually of this blending. An exception is so called "German Castrol", made in Germany and labeld in small print on the bottle. In the US it comes in 0W30 only and other than the made in Germany small print looks the same as made in USA 0W30.

Group V base stocks are ester oils and also a catch all for all other base stocks that don't fit into another catagory. Red Line is an example of an oil company that uses mostly ester based oils. Amzoil also uses a lot of ester on most blends.

Since Castrol won the lawsuit, other oil companies sometimes also use group III blending stocks for the "synthetic" oil. Valvoline is one of them.

The new Penzoil Platinum is sort of a unique case. It is a new base stock. As such it fits into the group V catagory as the catch all "everything else". It's actual performance is somewhere between group III and group IV.

So among the best oils by virtue of starting with the best blending stocks are Mobil 1, German Castrol, and Red Line. Torco fits in there too, but they really don't intend their product to be used for anything but racing and it does not carry API or ILSAC industry ratings.

Among the oils that are almost there, by virtue of using a base stock that performs nearly as well and using a killer additive package would be Castrol, Valvoline, and Pennzoil. The biggest difference being better pumpability when extremely cold and better able to handle extreme heat for longer periods of time.

The funniest part of this whole thing is that conventional oils have had to improve dramatically every time the API has a new standard about every 4 or 5 years. Conventional oils are carefully blended to meet these increasingly higher standards. To do so, they are using more and more group II+ and group III to blend their base stocks. As a result, today's conventional oils have greatly closed the gap toward the performance levels of synthetic. If you were to compare conventional oil of 20 years ago with todays conventional oil, you would see that today's conventional darn near is synthetic oil.

Also sort of funny, Mobil Clean 5000, their lowest priced "conventional" oil is group III. If it had a Castrol label on it, it would be call "synthetic".

Finally to directly answer your question, Mobil 1 is group IV, and both Valvoline and Pennzoil are made of something slightly less, but usually are priced as though they are the same.

Sorry about the "brain dump".

Jim Johnson 98 SVT 03 Escape Limited