Oil Question

[GLASEM]

Was at a friends repair shop and noted he has four types of oil

*Regular dino oil
*Full Synthetic
*Semi Synthetic
*Partial Synthetic

OK........what's the difference between a semi & partial synthetic?

Can a partial be used in an engine that calls for semi synthetic?

[theiceman]

have no idea .. but semi would indicate half synthetis half dyno .. ?

Partial would indicate some other percentage but not necesarily half ?

Taking this discusion further all semis are partial synthetic , but not all partial synthetics are semi synthetic ? ..

i think im gettin a head ache

[RedCoupe]

Pour yourself a glass of your favorite libation and sit down with your laptop in a comfy chair. Log on to bob is the oil guy and you will find moe than you ever wanted to know about oil.

[OsoMoore]

For an air-cooled car, you should use dino oil to avoid issues with your older engine seals.

Beyond that, there are many arguments which I won't go into. I use dino 20w50 or 10w40 for 3-season driving in Wisconsin.

[DRACO A5OG]

Oh no, not this again??? Please say it isn't so???

[RichardNew]

This is very similar to discussing religion.

Richard Newton
Historic Racing Images

[Trackrash]

Cool, another oil thread. Let me get the popcorn.

Seriously, Ultimate Motor Oil Thread or Why we hate CJ4/SM oils was started in 2007!
The oil companies re-formulate their oils all the time and lately they won't give out their formulas.
So what's a DIY guy to do?

[GLASEM]

Gee.......all I wanted to know what the difference between a semi and partial synthetic oil is
Was this TOO much to ask.....................

[HarryD]

No it is not too much to ask.

The type listed have to do with legal definitions.

The only two that are (kind of) clear is:

Dino Oil - refined from petroleum. In industry parlance, Group 1 or 2 oils.
Synthetic Oil - Made from non petroleum products. In Industry parlance Group 4 and 5 oils.

The others can contain a mix of type 1,2 3, 4 and 5 oils in some proportions or processed in interesting ways.

Simplify you life:

For non-roller tappet 911's, any oil with sufficient ZDDP is fine.

For Roller tappet cars, follow the manufacturer's recommendations.

[M.D. Holloway]

Originally Posted by GLASEM

Was at a friends repair shop and noted he has four types of oil

*Regular dino oil
*Full Synthetic
*Semi Synthetic
*Partial Synthetic

OK........what's the difference between a semi & partial synthetic?

Can a partial be used in an engine that calls for semi synthetic?

Regular is mineral oil based normally from refined crude although some oil can be made from natural gas.

As for synthetic, that is mineral oil that has been chemically changed in order to give it other characteristics such as better oxidation resistance or great temperature stability with out as much viscosity changes compared to mineral.

As for the para, partitial or semi those are all blends of synthetic and mineral. The actual percentage doesn't matter - no real legal opinion on what dictates what.

As for what is better? depends what your trying to achieve....

[911s55]

The End