I have read posts referring to Grp I, II. What does that mean? Thanks.
Please define Grp I, II
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Hope this helps. It is from Mobil's Australia website:
Originally Posted By: http://www.mobil.com/Australia-English/LCW/Audiences/Synthetic_V_Mineral.asp
There Are Four Different Types of Motor Oil Base Stocks
We know that basestock composition has a significant effect on the overall performance of motor oil. There are four different types of base stock used in the motor oil market today.
Group 1 - Conventional - Mineral oil derived from crude oil
Group 2 - Hydroprocessed - Highly refined mineral oil
Group 3 – Severe hydroprocessed - Ultra refined mineral oil
Group 4 – Full synthetics (chemically derived) - Chemically built Polyalphaolefins (PAO).
As it infers Groups 1 – 3 basestocks are derived from crude oil pumped from the ground whereas Group 4 basestocks are chemically derived, most often from ethylene gas, and contain none of the contaminants present in mineral oils. Just as distilled water is pure water derived from gas so Group 4 basestocks are pure oils derived from gas.
There is a Group 5 - Full synthetics (chemically derived) - Chemically built Esters .
Originally Posted By: http://www.mobil.com/Australia-English/LCW/Audiences/Synthetic_V_Mineral.asp
There Are Four Different Types of Motor Oil Base Stocks
We know that basestock composition has a significant effect on the overall performance of motor oil. There are four different types of base stock used in the motor oil market today.
Group 1 - Conventional - Mineral oil derived from crude oil
Group 2 - Hydroprocessed - Highly refined mineral oil
Group 3 – Severe hydroprocessed - Ultra refined mineral oil
Group 4 – Full synthetics (chemically derived) - Chemically built Polyalphaolefins (PAO).
As it infers Groups 1 – 3 basestocks are derived from crude oil pumped from the ground whereas Group 4 basestocks are chemically derived, most often from ethylene gas, and contain none of the contaminants present in mineral oils. Just as distilled water is pure water derived from gas so Group 4 basestocks are pure oils derived from gas.
There is a Group 5 - Full synthetics (chemically derived) - Chemically built Esters .
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"Just as distilled water is pure water derived from gas"??????????? What! Distilled water is derived from water.
85% of the ethylene is a gas yes, and it comes from crude oil. One of the first parts of the refining process.
Group 5 is a class of all others, including esters, bio-synthetics, etc.
85% of the ethylene is a gas yes, and it comes from crude oil. One of the first parts of the refining process.
Group 5 is a class of all others, including esters, bio-synthetics, etc.
Quote:
Group 2 - Hydroprocessed - Highly refined mineral oil
Group 3 – Severe hydroprocessed - Ultra refined mineral oil
I have to respectfully disagree with the presented definition of G-III oils presented here. The critical distinction here is that with G-III, the processing actually chemically changes the molecules of the feedstock from one structure, to another. Obviously, this also happens with the synthesis of G-IV and G-V oils as well (and is at the heart of the "synthetic" definition war...). Refinement vs synthesis. This may be a gross oversimplification of the distinction between the I, and II oils and the III, IV, and V stocks, but I think it captures the essence.
Another problem would be that PAOs are not the only G-IV oils. Alkylated napthalenes ANs are also G-IV (IIRC), as well as some other classes I can't think of at the moment. Johnny, I'll defer to you on this -- do the ANs fall in G-IV, or would they be considered "other", and thus G-V?
Group 2 - Hydroprocessed - Highly refined mineral oil
Group 3 – Severe hydroprocessed - Ultra refined mineral oil
I have to respectfully disagree with the presented definition of G-III oils presented here. The critical distinction here is that with G-III, the processing actually chemically changes the molecules of the feedstock from one structure, to another. Obviously, this also happens with the synthesis of G-IV and G-V oils as well (and is at the heart of the "synthetic" definition war...). Refinement vs synthesis. This may be a gross oversimplification of the distinction between the I, and II oils and the III, IV, and V stocks, but I think it captures the essence.
Another problem would be that PAOs are not the only G-IV oils. Alkylated napthalenes ANs are also G-IV (IIRC), as well as some other classes I can't think of at the moment. Johnny, I'll defer to you on this -- do the ANs fall in G-IV, or would they be considered "other", and thus G-V?
Originally Posted By: Johnny
"Just as distilled water is pure water derived from gas"??????????? What! Distilled water is derived from water.
I think they mean that when water is distilled it goes from liquid to gas phase, then back to liquid phase.
ekpolk, AN is in Group 5. Mobil's description of Groups 2 and 3 is the "For Dummies" version. This one may be better:
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API Base Oil Definitions
Group I base stocks contain less than 90 percent saturates and/or greater than 0.03 percent sulfur and have viscosity index greater than or equal to 80 and less than 120.
Group II base stocks contain greater than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and have viscosity index greater than or equal to 80 and less than 120.
Group III base stocks contain greater than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and have viscosity index greater than or equal to 120.
Group IV base stocks are polyalphaolefins (PAO).
Group V base stocks include all other base stocks not included in groups I, II, III or IV.
"Just as distilled water is pure water derived from gas"??????????? What! Distilled water is derived from water.
I think they mean that when water is distilled it goes from liquid to gas phase, then back to liquid phase.
ekpolk, AN is in Group 5. Mobil's description of Groups 2 and 3 is the "For Dummies" version. This one may be better:
-----------------------
API Base Oil Definitions
Group I base stocks contain less than 90 percent saturates and/or greater than 0.03 percent sulfur and have viscosity index greater than or equal to 80 and less than 120.
Group II base stocks contain greater than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and have viscosity index greater than or equal to 80 and less than 120.
Group III base stocks contain greater than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and have viscosity index greater than or equal to 120.
Group IV base stocks are polyalphaolefins (PAO).
Group V base stocks include all other base stocks not included in groups I, II, III or IV.
I need to learn to read between the lines. I thought someone had lost their mind. Yes, AN is in Group 5 class.
I don't know how they measure saturates, but I know of one oil company that says their Group II+ is 98% saturates and their Group III is 99.8% saturates. I believe if I remember correctly that PAO is 100% saturate. If that's the case the Group III is pretty darn close.
I don't know how they measure saturates, but I know of one oil company that says their Group II+ is 98% saturates and their Group III is 99.8% saturates. I believe if I remember correctly that PAO is 100% saturate. If that's the case the Group III is pretty darn close.
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Originally Posted By: Johnny
I need to learn to read between the lines. I thought someone had lost their mind. Yes, AN is in Group 5 class.
I don't know how they measure saturates, but I know of one oil company that says their Group II+ is 98% saturates and their Group III is 99.8% saturates. I believe if I remember correctly that PAO is 100% saturate. If that's the case the Group III is pretty darn close.
ROLF...
I too was reading it as though water comes from gas (gasoline). I was like, man, someone lost their mind! 
I need to learn to read between the lines. I thought someone had lost their mind. Yes, AN is in Group 5 class.
I don't know how they measure saturates, but I know of one oil company that says their Group II+ is 98% saturates and their Group III is 99.8% saturates. I believe if I remember correctly that PAO is 100% saturate. If that's the case the Group III is pretty darn close.
ROLF...
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