If you want to know the difference between synthetic and mineral oils, or how 0W-40 is different from 5W-50 oil (or what that "W" actually stands for!), then read this. I don't know the name of the person who wrote it (it wasn't me), but if I did I would give them credit for it. A great document and well worth a read when you have time.
A quick chemistry lesson for you all:
Chemistry as you may know is my forte, and to understand a lot of what I will talk about here an in the report requires a bit of an understanding of the organic chemistry of fuels and lubricants.
The basic core of lubricants and fuels is a group of organic compounds called hydrocarbons (HC), these being molecules that contain only hydrogen and carbon atoms. HC’s can be classed into three groups these being alkanes, alkenes and alkynes. Alkanes are those that have a single carbon to carbon bond in the molecule, alkenes have a double carbon to carbon bond and alkynes have a triple bond. Hence, all HC’s will end in either one of the above suffix’s (ane / ene / yne).
Butane (C4H10) is an alkane and therefore has single bonds between the carbons, whereas (C4H8) is an alkene and has double bonds and has lost two hydrogens to compensate for this extra bonding.
The names of the HC’s is dependent on the number of carbon atoms within the molecule. The following table shows the first part of the name and no of carbons and the ending can either be; ane, ene or yne.
Hydrocarbon | Name | Number of carbons | State at SLC | Notes
Meth | 1 | Gas | Common gas (cooking)
Eth | 2 | Gas | Used for plastics and synthetics
Prop | 3 | Gas| Compressed cylinder gas
But | 4 | Gas | Compressed lighter fluid
Pent | 5 | Gas / liquid Rapidly evaporates
Hex | 6 | Liquid
Hept | 7 | Liquid
Oct | 8 | Liquid | Prominent feature in ULP
Nan | 9 | Liquid
Dodec | 10 | Liquid | Prominent feature in diesel
- | >25 | Liquid | Think oil type fluid
- | >40 | Solid | Greases and waxes
- | >50 | Solid | Tar like substance
The states of the liquids can be changed depending on pressure, temperature and volume.
The greater the number of bonding, the higher the specific energy capacity, but the energy required to initiate the release of energy is also high (ie: combustion or ignition). Therefore, 1l of propane gas contains more energy than the same volume of methane but won’t ignite as readily.
On the other hand, for those into drag racing, is another type of organic compounds that includes the alcohols (OH). The system for naming alcohols is the same for HC’s, except they end with ‘anol’
For example, the simplest form is methanol with has the formula CH3OH. Next is ethanol C2H5OH and is the common alcohol in beer or wine.
Where it all starts and what the difference between synthetics and minerals and what’s the advantages of them?
Mineral bases are manufactured from crude oil, which has undergone a variety of complex separation operations. They are relatively inexpensive and deliver "average" performances. They are by far the most commonly used, for both automotive and industrial applications. Crude oil is obtained from the decomposition of organic matter (plants and animals). The consistency of the HC within the crude oil is extremely inconsistent, with anything from 1C right up to 58C. Such a mixture needs to be purified and refined. Mineral oil is the end result this purification process, where the consistency of the HC’s in better and there is also removal of sulphur and other contaminates.
Semi-synthetic oils are a mixture of mineral and synthetic bases (generally 70 to 80% mineral and 20 to 30% synthetic oil).
Synthetic oils are products created by the chemical reaction of several ingredients. Two main families are used for lubricant formulation :
• esters,
• synthetic hydrocarbons, in particular polyalphaolefins manufactured from ethylene.
These products have excellent physical properties and exceptional thermal stability. Synthetic oils, produced by complex chemical processes, are more expensive. However, they deliver "premium" performances :
• higher viscosity index,
• better thermal strength,
• and more oxidation-resistant
The same product can be done by continual refinement of mineral oils, but to start from scratch and produce a new synthetic type is faster, cheaper and therefore easier.
As far as the applications of them all, mineral oils are easily the most popular for no other reason than cost. Semi-synthetics are the best alternative for ‘running’ a new engine in. For a brand new engine, I strongly recommend that all motors, regardless if it’s a Ferrari or Daewoo, should be run in with semi synthetic oils. The reason being that it allows for all of the components to “key inâ€
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