What is Engine Oil?

What is Engine Oil?

When activ8 asked me to write their first blog on oil additives and my findings, I was a little nervous as not used to writing, I’m used to working on cars. However, when I thought about it a little more, I thought to myself, actually it’s a very easy subject to talk about and to be honest there’s an awful lot that is involved. I shall not dive in too deep and will keep this simple (I hope). Before we talk about what engine oil additives are, let’s talk about what engine oils are first.  If you google engine oil you will discover this.

‘Motor oil, engine oil, or engine lubricant is any one of various substances that consist of base oils enhanced with various additives, particularly anti wear additives, detergents, dispersants, and, for multi-grade oils, viscosity index improvers. Motor oil is used for lubrication of internal combustion engines. The main function of motor oil is to reduce friction and wear on moving parts and to clean the engine from sludge (one of the functions of dispersants) and varnish (detergents). It also neutralizes acids that originate from fuel and from oxidation of the lubricant (detergents), improves sealing of piston rings, and cools the engine by carrying heat away from moving parts. In addition to the aforementioned basic constituents, almost all lubricating oils contain corrosion and oxidation inhibitors. Motor oil may be composed of only a lubricant base stock in the case of non-detergent oil, or a lubricant base stock plus additives to improve the oil's detergency, extreme pressure performance, and ability to inhibit corrosion of engine parts. Motor oils are blended using base oils composed of petroleum-based hydrocarbons, polyalphaolefins (PAO), or their mixtures in various proportions, sometimes with up to 20% by weight of esters for better dissolution of additives.’ Google 2021

Reading this we would all believe that the oil alone is sufficient in keeping our engines running smoothly and efficiently.  However, anyone with a car and especially an enthusiast knows this isn't always the case.

The primary function of any engine oil additive is to provide a boost to the engine oil’s performance. Engine oil can already do so much on its own, but it can do much more when additives are present. Imagine not hearing the screeching noise as the engine goes, and it’s going to stay that way for a while, saving you money from fuel and possible engine damage.   Another factor of why you should choose a good one is due to the fact that some engine oils have weak formulation, which can be a potential threat to your vehicle the longer it flows through the engine.  This is every vehicle owner's nightmare.  Why pay for something that could in fact damage your engine?

Now this is where we start looking on the market for oil additives.  Engine oil additives are compounds of chemicals that are added to the engine oil to optimize the oil’s function. The basic functions are, of course, to reduce friction and prevent wear.  In practice, lubricants are called upon to fulfill other functions, some of which are equally vital to the operation of the equipment in which they are employed. 

  • Friction reduction – This reduces the energy requirements to operate the mechanism and reduces local heat generation.
  • Wear Reduction – An obvious need for keeping the equipment operating for a longer period and in an efficient manner.
  • Cooling – In an engine, the lubricant is an initial heat transfer agent between some parts heated by combustion (e.g., pistons) and the heat dissipating systems e.g., sump, cooling jacket. The lubricant dissipates heat generated by friction or the mechanical work performed.
  • Anti-corrosion – Either from its own degradation or by combustion contamination, the oil could become more acidic and corrode metals.  Moist environments and lack of use can also cause rusting of ferrous components.  The lubricant could counter all these factors.
  • Cleaning action – the oil should prevent fouling of mechanical parts from its own degradation products or from combustion contamination.  Deposits, usually classified by descriptive terms such as ‘solid carbon’ ‘vanish’ or sludge can interfere with the correct and efficient operation of the equipment.  In extreme cases, piston rings may become stuck and oil passages blocked, if the oil does not prevent these effects. Deposit prevention and the dispersion of contaminants are included under this heading.
  • Sealing – the oil should assist in forming the seals between pistons and cylinders (pistons to rings, and rings to cylinder wall).

In addition to providing these functions on a continuing and economical basis, a lubricant must have certain properties, that are dictated by the equipment in which it is used.  There are necessary compromises between antagonistic requirements, some listed as negative limitations, as summarized next.

An oil should not:

  • Have too low a viscosity - This will allow metal to metal contact and subsequent wear and can increase oil leakage.
  • Have too high a viscosity - This will waste power and, in the case of engines cause starting difficulties.
  • Have too low a viscosity index - This means that it must not thin down too much when hot (or thicken too much when cold).
  • Be too volatile - High volatility will appear as a loss of oil I.e., high oil consumption from the boiling away of the lighter constituents, and it has been said to also cause deposits.
  • Form unduly in service - If an oil foams, this can result in loss of the lubricating properties of the oil and/or loss of the oil itself from the engine.
  • Be unstable to oxidation or chemical attack - Engine oils in particular are subject to high temperatures and contamination by acids and other chemicals.  The oils must be resistant to these to preserve their beneficial properties.
  • Attack emission systems components, coating, or seals - Some equipment contains paints or coatings, and most have elastomeric sealing components.  None of these should be seriously degraded by the oil.
  • Produce Deposits from the residues - If an oil decomposes on hot metal components (e.g. in the ring zone), it produces oxidation products that polymerize to form a yellow or brown layer known either as ‘varnish’ or ‘lacquer’.  This can build up and further carbonize to solid carbon. Either type of deposit can prevent movement of parts that should be free to move (e.g. the piston rings).  Apart from not producing deposits in the combustion chamber, which would lead to pre-ignition.
  • Be unduly toxic or of unpleasant odor - This requirement is for the comfort and health of the user.
  • Be unduly costly - This is often a real restraint, not because expensive oils are not worthwhile in terms of engine operating economics, but because competition among suppliers limits the price that can be charged to the user, and hence the acceptable ingredient cost.

Reference - Automotive Lubricants Reference Book, Second edition.

Now I've mentioned just the starting point of lubricants and not even got into the science and findings behind it, which luckily for you I shall not do, for the fear of sending you off to sleep. Since there are many engine oil additives on the market, there are ways to find out if an additive is a good one or not, by going through the list above and then its trial and error.  Thankfully you have come to the right website for said additive. For many years oil additives have been debated about, are they any good? Do they work? Is it worth the extra expense? When should an oil be more than sufficient? These are just a few of the questions I have heard when speaking to fellow motor enthusiasts. 

After many years trying and testing many on the market and finding most really didn’t make much difference or none at all, I came across Activ8 Lubricants at the NEC, and I have never looked back.  It says exactly what it says on the label and more.  This product can be used even to stop your bed squeaking!! For me having an oil additive is like having butter on your toast, it’s a must or its dry and tasteless, Activ8 Oil additive is just like that for my vehicles.  With 28 years of experience, it sure is an additive you can trust, a business you can call and chat to about anything (and if you get Nicki, you could talk for hours about all sorts).  Chris and Tom have such a in depth knowledge about their product any questions I’ve had over the years have been answered quickly and fully, meaning I can fully trust what goes into my vehicles.  Couldn’t ask for anymore.