Synthetic oil is very different from traditional motor oil that is derived from crude petroleum. It is more consistently uniform on a molecular basis, lacks many of the impurities that traditional motor oil contains and can be modified to meet specific operatic and climactic conditions to optimize vehicular performance.
How synthetic oil differs from traditional
To begin with, the term "synthetic" does not necessarily mean that the oil was produced in a laboratory. It may actually start out with a crude petroleum base, but it undergoes a very different and much more complex distillation process, which changes the chemical structure of the oil.
Conventional oil contains molecules of varying sizes and has additives that do nothing to enhance the lubricating properties of the oil. This can lead to sludge and deposit build-up in the engine. Synthetic oil has hydrocarbon molecules that are much more uniform in size, and it does not contain any of the additives or impurities present in crude oil derivatives. This results in the oil flowing much more freely and leaving behind fewer deposits than traditional motor oil. The increased flow-rate capacity means the oil reaches the engine parts much quicker, resulting in greater mechanical-parts lubrication and decreasing mechanical wear-and-tear on those parts.
The economy of synthetic oil
A quality of synthetic oil that is highly desirable is its relative immunity to temperature extremes. It flows easier in cold weather and is more resistant to thermal breakdown in high-heat environments. This not only protects the parts of the engine better but results in much longer useable life of the oil, which reduces operating costs.
Another quality of synthetic oils that makes them superior to conventional oils is that the oil acts to actually clean out and remove sludge and deposits that may already be present in the engine-again, adding operating life to the engine and thereby reducing operating costs.
Synthetic oils are usually substantially more expensive than conventional or traditional motor oils. Obviously, this makes their initial use more expensive. But this cost amortizes nicely over the life of the synthetic oil. Due to the difference in the chemical structure between the two, synthetic oils tend to last considerably longer before requiring an oil change. As a compromise between the superior performance of pure synthetic oil and the lower cost of traditional motor oil, many manufacturers offer synthetic/conventional oil blends.
When to use synthetic oil
There are a few situations where synthetic oil is ideally suited for use.
Extremes in climactic temperature conditions are the first scenario. Synthetic oils flow easier and lubricate better in cold and don't break down as fast in hotter climes.
If you tow a trailer, boat or any other type of heavy equipment, this causes the engine to run at a hotter operating temperature. The synthetic oil's resistance to viscosity breakdown is ideal for that situation.
Lastly, if you own or operate a high-performance automobile or truck, it more than likely came equipped with synthetic oil as a new vehicle, and it would be most advantageous and advisable to continue its use.