Which one is synthetic or dino?

[kilou]

Hi,

I'm really confused on what is a synthetic oil or a conventional oil. I just read that on this forum:
"The Rotella Synthetic is a Conventional oil (GRP III)"

So it's synthetic....but it's still a conventional. Well here are the oils I've run on my engine. I'm now using the Motorex Select SPX 5W40 (probably a synthetic blend) and I'll do an AutoRX cleaning with it. After the rinse phase, I plan t switch on Mobil 1 SuperSyn 5W40. Could you please tell me if these following oils are synthtic or conventional please:

Castrol SLX 0W30
Castrol Magnatec 10W40
Motorex Select SPX 5W40
Mobil 1 SuperSyn 5W40

Thanks

 

[bar1]

Group III oil is considered synthetic (also in Europe).
It's highly "altered" mineral oil and for most use it's as good as group IV/V oil.
Only problem I see with group III oil is that it's priced (almost) as group IV oil even if it's basestock is cheaper.

 

[Ron AKA]

"Mobil 1" is a synthetic. Castrol desigates their synthetics as Syntec. Dino is an outdated term, and as you can see just confuses things. Many synthetics have highly refined conventional mineral oil base stock. These are called Group III base oils. I suspect the reason there is such a low price differential between what some think are "true synthetics" Group IV and what they think are Group III's is that these oils really are blends of the two and who knows how much of each is used. They do what they do to meet all the specs they choose too, and do the blending to keep the costs down. See this thread on this topic for more info.

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=015847

 

[dave1251]

Rotella is group III but is considerd slack wax. It is a very highly refinded base stock. This is the same base stock for shell's helix ultra.

 

[Triple_Se7en]

quote:

---

Originally posted by kilou:
Hi,

I'm really confused on what is a synthetic oil or a conventional oil. I just read that on this forum:
"The Rotella Synthetic is a Conventional oil (GRP III)"

---

Whoever wrote that sentence is WRONG! Group IIIs are synthetic - as are those with higher group numbers IV & V.

 

[kilou]

Thanks for all the details. So all Mobil 1 are synthetic (including SuperSyn 5W40)? Is this a groupIII or groupIV oil?

 

[Ron AKA]

Mobil 1's are synthetic. SyperSyn refers to the additive package. However I don't see a 5w40 grade listed on the US website.

Some would say Mobil 1 is a Group IV. I would suggest it may also contain Group III base oils. With either one they can say synthetic. They certainly make no claims at their website or on the bottle that is only contains group IV. It just says it is synthetic and uses high performance fluids.