group III or IV ?

[Mephy]

Which syntetic oils are better, the one that belongs to group III or IV ?

I heard that the ones to Group IV can have corrosive effect on some plastic materials .

Is it Thrue ?

 

[Steve S]

Where did you hear about the corrosive effect.

 

[cosynthetics]

"Best" is somewhat of a relative term.

As a general thought you can say that Group IV's are better as they are "true" synthetics instead of hydrocracked dino's.

Now that doesn't mean a group III won't be just fine in your application. PP has shown to be a favorite on here and is only a group III.

 

[Mephy]

Originally Posted By: Steve S
Where did you hear about the corrosive effect.


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

Go to Disadvantages they say the PAOs (polyalphaolefins) has this side effect