Updated: Nov 22, 2020
Synthetic oil is nonetheless oil, though it is somewhat man-made. Synthetic oil is made from a base oil, powder additives, and a carrier oil that enforces an even distribution of the additives.
Both synthetic oil and traditional motor oil are made from refining oil. Most synthetics begin with highly refined crude oil, pumped from deep underground. That is the same source as conventional oil. Other synthetic oils use artificially made compounds or a synthetic oil as a base oil. The primary difference between synthetic oil and traditional oil is at the level of refinement.
The base oil falls into one of several “oil grades” from mineral oils extracted from crude (Group I and II) to fully artificial, compound-based oils (Group V). All grades of oil are manufactured with additives that increase performance.
Refinement processes and ingredients also result in scientific control over molecular size and purity. That can lower friction, reduce engine sludge, and increase performance.
Synthetic oil technological advantages include:
Uniform molecular size means less friction
Refinement and engineering reduce deposits
Additives boost protection and can clean engines
Better function in cold and extreme weather
Cleaner oil with fewer impurities
Because synthetic oil is better on your engine and has fewer impurities, it can go longer than conventional oils or synthetic blends.
Schedule regular intervals. For conventional oil, twice a year is suggested as a safe way of keeping track. If you want to keep better track, every 7,500 miles is suggested for average cars. You should also change your oil filter every oil change. But, especially if using synthetic oil, every other oil change is sufficient if you don't regularly push your car hard or endure extreme conditions.
Check your owner's manual. Newer cars may be able to go 10,000 miles or only need an oil change once a year. Turbo engines and older cars may still require oil changes every 3,000 to 5,000 miles.
Synthetic oil change intervals range 10,000-15,000 miles or once a year (whatever comes first). Extended performance synthetic motor oil is on the upper top of that range. That extra 5,000 miles may be worth the investment.
Synthetic Oil vs. Conventional Oil
Visually, you cannot tell the difference between new synthetic and conventional oil. There are two major differences, however. First, how they are made is a distinction. We've explained that synthetic oil is far more refined than conventional oil.
Second, the way they run in your car is worlds apart. Used motor oil shows a lot thicker and sludgy in conventional oil vs. synthetic oil, given the same amount of wear. Synthetic oil is by far better for performance. It protects the engine due to lower levels of friction. Additives help clean the engine of deposits. And, fewer impurities mean it burns cleaner, thickens far more slowly, and has fewer deposits to start.
The benefits of synthetic oil vs conventional oil:
Better fuel and oil economy
Increased engine protection and wear from lower friction
Longer intervals between oil changes
Reduced engine drag from greater resistance to thickening
Oil effectiveness/quality is more predictable and uniform
Better all-weather protection
Quicker engine start time
Helps clean engine sludge and deposits
Synthetic oil is generally considered the best oil. It is designed for performance. However, that same manufacturing process makes it more expensive.
The real deal of synthetic oil vs. traditional oil:
Better gas mileage won’t be an obvious difference to your short-term budget
The added engine protection may save costs overall
Synthetic oil is 6x – 10x the cost of traditional oil
Switching to synthetics can clean deposits that are plugging leaks (You really shouldn’t have bad seals in the first place)
You can switch back and forth between synthetic and traditional oil without consequence
All cars benefit from the additives in synthetic oils
How to Choose the Best Motor Oil for Your Car
If you can afford it, choose a full synthetic oil. It is the best oil for any engine. Synthetic oil cuts down the hassles or oversights related to more frequent oil changes and deposits.
If synthetic oil is too expensive, go with a blend or rotate between a full synthetic and non-full synthetic every other oil change. Changing car oil will not damage your vehicle. Keep a record to remember the mileage, next oil change date, and type of oil.