Synthetic or Conventional Oil: Which Is Better For You

Written by Katie Bushey (please see editor’s note at the bottom)

Synthetic oil is more expensive than conventional oil, but is it worth it? According to our expert mechanics, it doesn’t always pay to use more expensive oil. Every technician interviewed for this article agreed: it’s not what you use, but how you use it.

“Oil, in it’s most basic use, is there to lubricate and cool down moving parts,” said Elliot Matos, service manager for Hoffman Audi and Porsche, with more than 15 years of experience running Japanese, American and German service departments. “Any oil will do that. Synthetic was designed with a particular purpose in mind; it’s only recently we’ve seen manufacturers make a push for synthetic and synthetic blends.”


Originally designed for fighter jets and race-cars, synthetic is meant to withstand demanding conditions – such as temperature extremes. Motor oil contains detergents, and those in synthetic are of higher quality than conventional. The higher quality ingredients help the oil maintain its integrity longer.

“Synthetic keeps an engine cleaner. It’s also more stable than conventional, because the additives don’t break down as quickly as conventional,” said Kevin Biedleman, Hoffman Audi technician. “The synthetic ingredients dissipate heat more effectively – and lubricate better – than conventional.”


Although synthetic may look better on paper, it’s simply not necessary for drivers that spend a majority of their time on the highway, drive a newer vehicle or don’t experience major temperature extremes. Engines run hotter when working at high speeds; more of the detergents in the oil to burn-off, rather than break-down into carbon deposits and gum up the engine. For new vehicles, whose parts are not worn down from use, conventional is just as effective as synthetic. And if your vehicle rarely experiences temperature extremes – maybe you winter in Florida, for instance, and never drive your vehicle in the cold – then synthetic may be a waste of your money.

City driving, towing and older vehicles will benefit from synthetic, however.

“Synthetic is chemically-based, meaning it has fewer naturally occurring impurities,” explained Matos. “Conventional naturally has wax, sulfur and asphaltic particles in it.”

City driving, with it’s constant starts and stops, puts stress on the engine. Towing, meanwhile, requires the engine to produce more power for the same effect. Conventional oil simply puts another stressor on an already burdened engine. For older vehicles, consider switching to synthetic. The superior lubrication – and the cleaner oil – will help worn parts function better.

Although consistency is always the best way to keep a car running longer, switching from conventional to synthetic oil – or vice-versa – once or twice won’t damage the engine. In an emergency, don’t be afraid to top off your synthetic oil with conventional or conventional with synthetic. No oil in your engine is worse than mixing oils in an emergency, explained Matos. No oil in your engine can cause it to seize, and potentially total it.

No matter which oil you choose, oil changes will still be necessary. Both oils use the same filters, but synthetic is more expensive than conventional. Despite the additional cost of synthetic – usually $25 more expensive than conventional – most drivers don’t mind shelling out the extra cost up front.

“Synthetic can generally last 5,000 to 10,000 miles between changes, whereas conventional is recommended to be changed by 5,000 miles,” said Biedleman. “Most drivers feel the added cost of synthetic is worth it, because they can go longer between changes.”

“Engines are designed to run a specific conventional or synthetic oil weight, or thickness, so you should always use what’s recommended by your manufacturer in your owners manual,” said Biedleman. The numbers on oil bottles – 0W up to 25W, or ranges from 20 to 60 – correspond to the oil weight, with 0W the thinnest oil. The “W” denotes that the oil is suitable for cold weather. “Manufacturers list acceptable weights to use in your engine, so that you can vary your oil depending on use. The hotter the engine, the higher the weight you want to run.”

Editor’s note: is a consumer auto guide which I helped to create in return for a marketing fee. The columns that I publish from are edited by me and sometimes, like in this case, the topic was suggested by me. In full disclosure, my son Ethan Gombossy is the Porsche service representative for Hoffman. And of course from time to time the dealership pays for advertising on Obviously I have such a huge conflict of interest that I cannot publish any positive or negative comments from readers about Hoffman Auto Group. As I have in the past, any complaints that I receive about the dealership I turn over to owner Brad Hoffman.

Katie Bushey – the author of this article – is Hoffman’s public relations director. You can contact her at

George Gombossy: Editor & Publisher of, and


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4 Comments on "Synthetic or Conventional Oil: Which Is Better For You"

  1. And what exactly makes any of these guys oil experts? Do they even know what Reynold’s Number is? What do they know about ZDDP levels? Do they understand what 5W-30 really means? I doubt it!

  2. Dontsellout | August 1, 2011 at 5:30 pm |

    So if the CT State Attorney’s office was investigating Hoffmann you couldn’t write an arcticle about them?

    Sounds way too familiar with Sleepy’s and the Courant…..

    • I think you raise a valid point. Upon reflection, I changed the disclosure to say that I would not publish any positive or negative comments from readers about the Hoffman dealerships.
      And of course I would publish a story if the dealerships were being investigated by police or any authority.
      The difference between CtWatchdog and The Courant is that I disclose ALL my conflicts of interests in the ABOUT page so that readers will know what areas I may not be objective. The Courant claims it treats all companies the same whether they are major advertisers or not. We know that is not true.

  3. Konrad Feierabend | December 23, 2014 at 8:20 pm |

    Drove my 85 cutlass supreme for over 700,ooo km and 17 yrs to work 145 km return daily and all I used reg oil 10w30 castrol @ 10,000 km intervals.Too bad road salt killed it.Best car ever!! kitchener canada

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