For many people, the only thing that they know about synthetic oil is that it’s a lot more expensive than the regular stuff. There’s a big reason for that, which we’ll get into later, but knowing what you’re using isn’t just wise: it’s pretty much necessary in the modern world.
So, let’s hop into the exciting world of synthetic oils and we’ll discuss the difference between them and their more conventional counterparts.
What exactly is it?
Synthetic oil is distinguished from conventional, or mineral, oil by one big factor: synthetic oil is derived from purified petroleum components instead of directly from crude oil.
It can also be synthesized from different base stocks.
Oils are separated into five different groups. Group I and II are the so called standard oils, while Groups III, IV, and V are considered synthetic in increasing amounts.
Remember that not all synthetic oils come from something other than crude oil. Group III oils are still derived from a petroleum base although they’ve been purified and modified enough that they fall under the legal definition of synthetic oils.
Group IV oils are derived from poly-alpha-ofelin, or PAO. Simply putting it, this is considered to be a 100% synthetic chemical from which synthetic oils can thus be derived. Currently, PAO can be derived from both petroleum based products or sourced biologically.
Group V oils, on the other hand, are defined as any type of oil which is made from compounds other than mineral oils or PAO. A chemical group known as esters are responsible for most of these, and are formed by condensing an acid with an alcohol.
Many of these are used as additives to other oils, creating semi-synthetic oils.
For the most part, synthetic oils are used as motor oils. They offer some pretty impressive advantages over their less refined counterparts however, due to both their carefully controlled construction and the additional processes.
The advantages of synthetic oils
Mineral oils are actually a complex mixture of hydrocarbons and paraffins, not a single compound as many people think. By controlling the individual components placed into a base oil, as is the case for synthetic oils, the performance can be optimized.
As a general rule these oils perform better. It’s not even a trade-off, for the most part they’re just better.
Of course, they also cost a whole lot more, so there’s a little bit of a trade-off. Even for those Group III oils which are still produced from base oil stock they tend to perform for longer which makes them a little bit more viable despite the high costs.
As a general rule, they offer the following improvements:
- Higher viscosity
- Better performance at temperature extremes
- Better chemical stability
- Lower volatility
- Superior “hot spot” protection from deposit formation
- Improved fuel efficiency
- Easier starts in extreme cold
All of this makes synthetic oils an attractive option for many vehicles, especially since it has to be replaced less than conventional oils.
The reasons for these advantages are pretty clear once you understand a few more things about synthetics.
Greater purity through chemical engineering
Oils which are derived conventionally contain a lot of compounds which invite the formation of sludge. Nitrogen, sulfur, and other impurities can oxidize or other become denatured due to the high pressures and temperatures which most oils are subject to.
By engineering the oil from refined components in the first place these can be avoided. This leads to a longer lifespan for synthetic oils, and also helps them to avoid forming deposits in areas which naturally get hotter than the block of an internal combustion engine.
Greater purity leads to a longer life for oils and leads them to be much cleaner, which not only prolongs the life of the oil but can also lead to less wear-and-tear on the engine they’re being used in.
Uniformity of ingredients
Cruder motor oils are always going to have some amount of deviation from batch to batch. Synthetics specifically avoid this, which makes their performance completely predictable and also helps keep them functioning at the extreme ends of a motor’s functional range.
Their uniform compositions also help to make them a better overall lubricant than their conventional counterparts.
Oil by design
Since synthetic oils are produced to meet specific needs and are completely uniform a good term for them might just be designer oils.
By being specific in their design, synthetic oils can naturally be made to last longer. Additives can also be produced which help to improve fuel efficiency of a motor and increase power in the motors they’re added to.
Are synthetic oils greener?
When it comes down to it, synthetic oils can be much greener than their counterparts. This isn’t always the case, however, and the economic hit to the end consumer can definitely be a high price to pay since they cost on average three times more than their conventional counterparts.
There are two big reasons why, without even getting into synthetic oils produced from biological sources rather than from petroleum.
The first simply comes from the fact that synthetic oils last for much longer than their conventional counterparts, leading to less oil changes over time and less oil consumption in total.
The second reason is that they are much less volatile than conventional oils. This leads to less instances of needing to add oil to the motors involved. The volatility of synthetic oils ranges from 4-10% while conventional oils can lose up to 20% of their volume in the high heat conditions contained within a motor.
Bio-oils
While most modern synthetic oils are produced through some form of petroleum based products, companies are currently bringing products to market which require virtually no input from the petroleum industry. Some of them have even ended up being biodegradable as well which reduces environmental impact in the event of spills or irresponsible disposal.
While refined oils are, to some degree, biodegradable they take much, much longer to be broken down in the environment. That doesn’t make these oils harmless, however, so it’s still not good practice to dump them in the storm drain.
At this point in time, however, biologically derived oils still have some pretty serious issues. One of the primary complaints is that they have a tendency to freeze or congeal at extremely low temperatures.
Most of the oils currently on the market which fall into this category are combinations of biologically-derived PAO, falling under the Group IV classification and Group V additives.
The overall advantage
The largest advantage doesn’t yet come from “true” synthetic oils, instead it boils down to the fact that synthetic motor oils last much longer than their counterparts and burn off much slower.
Overall, this could possibly lead to a much reduced demand for oil as more and more manufacturers require it in the directions for using their motors. Reduced demand, on a large scale, means a lot less oil required by motors.
A lessened demand for oil, means less environmental impact. Both from spills and on the production side of things.
The environmental advantages of synthetic oil are, for the most part, rather indirect but on a larger scale they can definitely be invoked to make things a lot greener when it comes to oil production.
There’s a hidden advantage as well: by increasing fuel efficiency, synthetic oils can also reduce the demand for gasoline in many cases.
The mythology of synthetic oils
Despite not being all that new to the market, there are quite a few myths which surround the use of synthetic oils.
The biggest myth boils down to the idea that you can’t switch back and forth between synthetic and conventional oils in a vehicle. This simply isn’t true, and indeed oil manufacturers themselves quite often mix conventional and synthetic oils, resulting in oil branded as a “synthetic blend.”
In fact, they’re completely compatible even if you’re just topping off.
The other one that worries some people is that synthetics have been reputed to wear down seals and gaskets. This might have been true with the old ester based oils, but it’s simply a myth with modern oils.
If you’ve been using conventional oil for quite some time then you may suddenly have a leak or two… because synthetic oil is more pure and can remove some of the deposits left by conventional oil which may have concealed problems which were already present.
They’re also tend to be less viscous, which can also cause them to spring through areas where conventional oil flowed without leakage.
Conclusion
Overall, synthetic oil is quite a bit different from the old-fashioned stuff. Even if it doesn’t work miracles for engines or the environment the advantages end up being quite numerous.
Even in the case of oils which are still derived from a base petrochemical stock, the greater purity and uniformity provided by them offers an impressive view of just how much chemical engineering has changed over the last century.
And it’s easy to see why they’re becoming more popular, once you understand what synthetic oil actually is. You don’t need to be a chemical engineer to see why synthetic oils are rapidly replacing conventional oils in engines all over the world.