Lubricating oil base stocks are generally broken down into 5 categories:
Group I and II are conventional petroleum, and differ primarily in sulfur content.
Group III is hydroprocessed petroleum oil -- basically an extra refining step. The FTC ruled in court that this could be called "synthetic", even though it is 100% petroleum.
Group IV and V are the true synthetic PAO and Esther based synthetics.
So yes, the oil companies do produce different products. The group I/II is primarily determined by how the crude comes out of the ground, but the group III is a separate product with the extra refining step. The group IV and V basestocks do not contain petroleum so they are a whole different class of material.
Most synthetic blends are a mix of group I or II and group III base stocks. So, they are 100% petroleum. Also, many of the so called "synthetics" are group III petroleum oil. The group III petro oil actually performs almost as well as true synthetics, at almost the same cost as the true synthetic.
I agree with the others -- you really don't know what you are getting with blends -- it's just marketing to lower price points.
Dave
Group I and II are conventional petroleum, and differ primarily in sulfur content.
Group III is hydroprocessed petroleum oil -- basically an extra refining step. The FTC ruled in court that this could be called "synthetic", even though it is 100% petroleum.
Group IV and V are the true synthetic PAO and Esther based synthetics.
So yes, the oil companies do produce different products. The group I/II is primarily determined by how the crude comes out of the ground, but the group III is a separate product with the extra refining step. The group IV and V basestocks do not contain petroleum so they are a whole different class of material.
Most synthetic blends are a mix of group I or II and group III base stocks. So, they are 100% petroleum. Also, many of the so called "synthetics" are group III petroleum oil. The group III petro oil actually performs almost as well as true synthetics, at almost the same cost as the true synthetic.
I agree with the others -- you really don't know what you are getting with blends -- it's just marketing to lower price points.
Dave