oil question
Burning Brakes
Joined: May 2008
Posts: 1,165
Likes: 24
From: Boston MA
some more clarification; lifted from Mobil 1;
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.
Additives:
Additives enhance the performance of motor oil basestocks and help adjust the performance of the oil to suit its intended application. Additives are the key to unlock the performance potential of basestocks but even the best additives won’t turn bad oil into good oil.
Some common additives include:
• Viscosity Index Improvers – improve ability to handle heat and severe conditions
• Pour Point Depressants – lower oil freezing point in cold conditions
• Anti-wear Additives – protect against metal-to-metal contact
• Detergents & Dispersants – keep components clean and prevent sludging
• Oxidation Inhibitors – maintain oil stability over service intervals
• Corrosion & Rust Inhibitors – protect against the effects of condensation
• Defoamants – prevent oil foaming and cavitation
Additives work symbiotically with the base stock and are added in different proportions according to the application. Some examples are that racing oils may not require rust inhibitors but could need extra defoamants for dry sump oil systems, domestic or consumer engine oils may need special additives that don’t interfere with the operation of catalytic converters or diesel oils may require additional protection against combustion byproducts.
Conventional motor oils use base stocks created by the conventional refining of crude oil pumped from the ground. Crude oil is a complex mix of hydrocarbon compounds and a variety of sophisticated refining techniques are used to remove/reduce the amount of undesirable components such as asphalts, waxes and chemically unstable sulphur & nitrogen compounds. Conventional motor oils use conventional mineral base stocks so are usually known as Mineral oils.
Mineral base oils have performance limitations. After refining what remains is a lubricating base stock that despite the degree of chemical refinement still contains undesirable materials such as oxygen, sulphur, nitrogen compounds, trace metals and carbon residues.
There are literally thousands of compounds present in crude oil. While many of them are removed or upgraded by refining, a significant concentration of these undesirable materials remains in lubricating oil base stocks. These residual undesirable materials mean additive packs can’t operate to full effect because the additive has to compete for space with the impurities when they attempt to bond with the baseoil molecules. Consequently the molecular structure of the oil is inconsistent, limiting the performance capabilities and useful service life of the resulting blended oil.
Hydroprocessed Oil
Hydroprocessed motor oils use base stocks made by the additional refining of mineral oil. While refined to a greater extent than conventional mineral base oils, hydroprocessed base oils still have similar performance limitations due to the presence of undesirable impurities which cannot be completely removed from crude oil. Hydroprocessed motor oils use extra refined mineral base stocks.
Severe Hydroprocessed Oil
Severe hydroprocessed oils are further refined hydroprocessed oils but they still contain some undesirable impurities which cannot be completely removed. Most engine oils on the Australian market advertised as synthetic use severe hydroprocessed basestocks.
Semi-Synthetics
Semi-Synthetics use base stocks comprising conventional or hydroprocessed base oil in combination with severely hydroprocessed or synthetic (PAO) basestocks. The proportion of severely hydroprocessed or synthetic basestocks in semi-synthetic oil is a closely guarded secret, but is usually between 10% and 25%.
Synthetics
Synthetic motor oils contain a high proportion of base stocks created from pure chemicals. Since synthetic base stocks such as PAO are essentially pure chemicals themselves they avoid the performance limitations imposed by the impurities present in conventional and hydroprocessed base oils. PAO synthetic base oils are therefore pure compounds containing none of the impurities found in conventional base oils derived from crude oil, as mentioned earlier.
In addition, chemically derived synthetic base stock technology allows the base oil molecules to be designed specifically for particular lubrication applications with purpose designed features such as the exact desired viscosity, superior viscosity stay in grade capability, low volatility etc. Synthetic base stocks can also be specifically tailored to suit different additives required for different applications. Additionally because synthetic oils are ‘pure’ they contribute lower emissions and are kinder to catalytic converters. Synthetic oils can also be engineered to have less internal molecular friction allowing an engine to develop maximum power and provide best possible economy.
Synthetics can therefore be "tailored" to suit specific lubrication applications. The molecular engineering that goes into chemically derived synthetic base stocks enable a base oil to be designed for a specific purpose. For example specific base oil molecules have been designed for use in Mobil Jet Oil II (which is used by 70% of the world’s commercial jet aircraft). Similarly and very specific Mobil 1 formulations have been designed for Formula 1 racing applications. This same highly specific molecular engineering approach has been used to design the best base oil molecules for use in consumer synthetic motor oils such as Mobil 1.
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.
Additives:
Additives enhance the performance of motor oil basestocks and help adjust the performance of the oil to suit its intended application. Additives are the key to unlock the performance potential of basestocks but even the best additives won’t turn bad oil into good oil.
Some common additives include:
• Viscosity Index Improvers – improve ability to handle heat and severe conditions
• Pour Point Depressants – lower oil freezing point in cold conditions
• Anti-wear Additives – protect against metal-to-metal contact
• Detergents & Dispersants – keep components clean and prevent sludging
• Oxidation Inhibitors – maintain oil stability over service intervals
• Corrosion & Rust Inhibitors – protect against the effects of condensation
• Defoamants – prevent oil foaming and cavitation
Additives work symbiotically with the base stock and are added in different proportions according to the application. Some examples are that racing oils may not require rust inhibitors but could need extra defoamants for dry sump oil systems, domestic or consumer engine oils may need special additives that don’t interfere with the operation of catalytic converters or diesel oils may require additional protection against combustion byproducts.
Conventional motor oils use base stocks created by the conventional refining of crude oil pumped from the ground. Crude oil is a complex mix of hydrocarbon compounds and a variety of sophisticated refining techniques are used to remove/reduce the amount of undesirable components such as asphalts, waxes and chemically unstable sulphur & nitrogen compounds. Conventional motor oils use conventional mineral base stocks so are usually known as Mineral oils.
Mineral base oils have performance limitations. After refining what remains is a lubricating base stock that despite the degree of chemical refinement still contains undesirable materials such as oxygen, sulphur, nitrogen compounds, trace metals and carbon residues.
There are literally thousands of compounds present in crude oil. While many of them are removed or upgraded by refining, a significant concentration of these undesirable materials remains in lubricating oil base stocks. These residual undesirable materials mean additive packs can’t operate to full effect because the additive has to compete for space with the impurities when they attempt to bond with the baseoil molecules. Consequently the molecular structure of the oil is inconsistent, limiting the performance capabilities and useful service life of the resulting blended oil.
Hydroprocessed Oil
Hydroprocessed motor oils use base stocks made by the additional refining of mineral oil. While refined to a greater extent than conventional mineral base oils, hydroprocessed base oils still have similar performance limitations due to the presence of undesirable impurities which cannot be completely removed from crude oil. Hydroprocessed motor oils use extra refined mineral base stocks.
Severe Hydroprocessed Oil
Severe hydroprocessed oils are further refined hydroprocessed oils but they still contain some undesirable impurities which cannot be completely removed. Most engine oils on the Australian market advertised as synthetic use severe hydroprocessed basestocks.
Semi-Synthetics
Semi-Synthetics use base stocks comprising conventional or hydroprocessed base oil in combination with severely hydroprocessed or synthetic (PAO) basestocks. The proportion of severely hydroprocessed or synthetic basestocks in semi-synthetic oil is a closely guarded secret, but is usually between 10% and 25%.
Synthetics
Synthetic motor oils contain a high proportion of base stocks created from pure chemicals. Since synthetic base stocks such as PAO are essentially pure chemicals themselves they avoid the performance limitations imposed by the impurities present in conventional and hydroprocessed base oils. PAO synthetic base oils are therefore pure compounds containing none of the impurities found in conventional base oils derived from crude oil, as mentioned earlier.
In addition, chemically derived synthetic base stock technology allows the base oil molecules to be designed specifically for particular lubrication applications with purpose designed features such as the exact desired viscosity, superior viscosity stay in grade capability, low volatility etc. Synthetic base stocks can also be specifically tailored to suit different additives required for different applications. Additionally because synthetic oils are ‘pure’ they contribute lower emissions and are kinder to catalytic converters. Synthetic oils can also be engineered to have less internal molecular friction allowing an engine to develop maximum power and provide best possible economy.
Synthetics can therefore be "tailored" to suit specific lubrication applications. The molecular engineering that goes into chemically derived synthetic base stocks enable a base oil to be designed for a specific purpose. For example specific base oil molecules have been designed for use in Mobil Jet Oil II (which is used by 70% of the world’s commercial jet aircraft). Similarly and very specific Mobil 1 formulations have been designed for Formula 1 racing applications. This same highly specific molecular engineering approach has been used to design the best base oil molecules for use in consumer synthetic motor oils such as Mobil 1.
