Synthetic Oil vs. Conventional Oil

July 14th, 2016

This week, we’re gonna have synthetic oil and conventional oil duke it out. If you think like me, maybe this already crossed your mind: synthetic oil sounds like it wouldn’t be as good. I associate the word “synthetic” with “fake” or “unnatural,” so it has a negative connotation to me. I wouldn’t want to feed my car anything “synthetic,” I would want the real deal! Is that really the case, though? Is the natural-based motor oil better than the manufactured one? Let’s find out.

Conventional Oil

Conventional, or “regular” oil, is your basic petroleum-based oil that contains natural minerals. If you recall, the purpose of oil is to clean, lubricate, and cool your engine (which is why it’s important to check your oil level). For many older cars, conventional oil is perfectly capable of doing these jobs. We’ll get into the details of synthetic oil in a bit, but one thing about it is that it’s often more expensive than conventional. If you find that conventional oil works just fine for you, then it may not be worth it to upgrade to synthetic.

Synthetic Oil

In more recent years, manufacturers have been making it a requirement for newer vehicles to already come with synthetic oil in the engine, and for good reasons. For one thing, synthetic oil is made artificially, making it easier for people to engineer it to work optimally with newer engines. It’s comprised of molecules that are pretty small and uniform in size, so it keeps your engine cleaner by making it flow much more smoothly in your engine. Conversely, owners of vehicles with older engines may find that synthetic oil tends to leak through the seals and other areas. Because of the already hefty price of synthetic oil, it would be a waste if it was just going to leak out.

Due to the way companies engineer synthetic oil, they often make it so the oil resists extreme temperatures. In the mornings where it tends to be cooler, it takes a while for conventional oil to warm up and flow smoothly throughout your engine. Of course, this is especially true in colder, freezing temperatures. You may have heard the term “viscosity” when it comes to oils, and basically this just means a liquid’s ability to flow. Synthetic oils are made to have a lower viscosity, meaning it will flow easier than conventional oil.

Engines run very hot, and the sweltering summer heat doesn’t exactly help. Conventional oils tend to break down and even evaporate due to the heat. Because of this, this means less lubrication for your engine, making it more susceptible to wear and tear. Synthetic oil, however, is made to resist hotter temperatures to protect your engine.

Which is better?

After reading these points, it seems like the obvious chance would be synthetic. It has lower viscosity, resists hotter temperatures, and is cleaner than conventional. However, before making the switch, it would be wise to consider the following:

  • Is your car older? If so, you may be just fine using a conventional motor oil. As mentioned earlier, putting synthetic oil in an older engine could cause a lot of leaks, making it not worth it to purchase the more expensive oil option.
  • Even if your car isn’t older but it’s still running conventional oil, you may find that it gets the job done. Again, not every vehicle needs synthetic oil. Make sure you’re not wasting money by buying a more expensive oil that doesn’t produce better results for you.

The owner’s manual of your vehicle should let you know what oil you should be using. In some cases, switching from synthetic to conventional won’t damage your engine; but with tight, high-performance engines, synthetic oil is required so it won’t clog up your engine so easily. Think of the 2015 BMW 650i; a car like that would require synthetic oil. It would be ok to mix it with a bit of conventional oil, but anything too much would cause the viscosity level to rise, and you might clog your engine and put a halt to your trip. I wouldn’t risk it; you don’t want anything to stop those beautiful 650i wheels from turning!

So, the ultimate conclusion is that there isn’t really a clear winner. It all depends on your vehicle, and maybe where you live (you may want to opt for synthetic in colder climates so it can flow more quickly when starting your car).

Stick with conventional if you find it works fine for you, but if you have a newer engine and you’re willing to spend more for a better performance, then try synthetic oil and see how you like it!


“Oil” see you next week 😉
– Kathy


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