Synthetic Blend vs Full Synthetic vs Conventional (Oil Comparison)

Last Updated on May 1, 2020

When you go to get your oil change service done you probably don’t think too much about the type of oil they’re putting into your engine. But it is important to know what type of oil your car’s manufacturer recommends for your vehicle so you don’t put in the wrong oil and shorten the lifespan of the engine.

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Many newer cars have high-performance or turbocharged engines in them which generate more heat than conventional engines. Because of this heat, these high-performance engines need oil which can sustain higher temperatures without breaking down as easily.

In these cases, the type of motor oil you use makes a big difference. Here’s a comparison of the three main types of engine oil on the market today.

Related: Common Oil Change Scams to Be Aware Of

Conventional vs Synthetic Blend vs Full Synthetic

In a nutshell, full synthetic oil is far superior to conventional oil because of its longevity. Full synthetic oil also won’t break down as quickly when it faces hot temperatures from the engine or from the weather outside.

Engine operating temperature is the biggest factor when it comes to engine oil but climate can also have some effect. That is why if you live in Arizona or some other southern state with extremely high temperatures, it’s a good idea to have full synthetic oil in your vehicle so it doesn’t break down that quickly.

There is actually a third choice for oil that a lot of people don’t talk about. It is the synthetic blend oil which is kind of like a hybrid of conventional oil and full synthetic oil. The two oils are basically mixed together so that you’ll have oil that is a little bit better than conventional oil.

People may want to purchase the synthetic blend because it is cheaper than full synthetic oil and still has more longevity than conventional oil. Of course, full synthetic oil has a longer change interval but it is more expensive.

Overall, you should purchase full synthetic oil if you don’t mind paying a little more for it. Synthetic oil creates less resistance inside of a car’s engine which means you’ll have better engine efficiency and horsepower.

As a result, you’ll end up using less gas in your vehicle and promote a better fuel economy. Plus, if you don’t typically drive long distances with your vehicle then your engine isn’t going to heat up as much.

So you could get away with changing your synthetic oil every 5,000 or even 10,000 miles instead of every 3,000 miles like you had to do with conventional oil. But make sure you also consider the car manufacturer’s recommended oil change interval.

Make sure you don’t go too long before an oil change and oil filter change because the oil will break down from being too old at this point.


12 thoughts on “Synthetic Blend vs Full Synthetic vs Conventional (Oil Comparison)”

  1. Man, this article…

    If you have a high performance engine and your owner’s manual says you must use synthetic oil, then that’s the only thing you should put in your engine. If your manual does not, then you can pamper it with synthetic if you want.

    If you live in places that see snow, this isn’t a reason to get conventional because it doesn’t get hot, this could be just as much a reason to get synthetic, because synthetics tend to flow much better than conventionals during that critical start-up in freezing temperatures.

    Also, if you don’t drive long distances it’s actually worse for your oil, not better. The primary factor is not because there is a lack of heat degrading the oil, but because the lack of heat means moisture and impurities that accumulate in your oil won’t get boiled away as they should normally. Then you may want the higher quality properties of a synthetic to counteract the fact that your oil is dirtier.

    But both oils will still be dirtier meaning you should just change it sooner, but then some people might conclude that the mileage longevity of a synthetic is being wasted if they are going to change it so often anyways.

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  3. I have 90,000 miles on my pickup truck and I think that the dealer has used full synthetic dexso oil in a time or two. My Question is, does it do any damage to switch back and fourth with a blend synthetic to full synthetic? Larry McEwen

    • It won’t do any damage. Although in my mind, a synthetic blend is not much better than a conventional oil. Either go full synthetic or standard conventional.
      As you add more miles to your truck, I’d consider changing to conventional, especially if you notice any small oil leaks. The properties of synthetic oil sometimes allow it to squeeze through tiny cracks in seals/gaskets which are more common on higher mileage vehicles.

  4. If your car company recommends synthetic oil use it period! If your car calls for conventional motor oil, you may want to change to a synthetic blend as your car gets older due its ability to tolerate higher operating temperatures (cooling systems tend to be less efficient the older they get). Synthetic blend will lubricate better also.

  5. Have a 1966 chev. 283 that has been beef up a little with 30,000 miles on this motor using 10w30 conventional val. oil. can I go to a full Syn oil? I’m still going to change the oil at 3,500 miles. I do not drive this car a whole lot. Have antigue tags on it plus I don’t need any damage to happen.

    • In my opinion, I’d highly recommend to continue using conventional oil. Older cars were simply not manufactured with the tight tolerances of modern cars. Synthetic oils have different flow characteristics vs conventional and will find tiny cracks and crevices which can result in leaks.

  6. I have a friend that was a tugboat engineer then captain. He said that after they changed to full synthetic, the engines lasted far longer between overhauls. Being as they run 24/7, that was a huge savings. But he also said that the synthetic also has better film strength and stays on the cylinders longer so for engines that aren’t used often, like mu sailboat auxiliary engine, it is even more important.

    Is that all true?

    • When it comes to oil, it’s usually best to stick to the manufacturer’s recommendations. If my vehicle required full synthetic and someone used a synthetic blend instead, I’d change it just to be on the safe side. If you can show they made a mistake, you may be able to get them to put the correct stuff in at no charge to you.

  7. The facts are that if your owner manual states to use synthetic oil, its only to save fuel and extend oil change intervals. This is mandated by governments. True, synthetics have slightly better friction properties. But, using good quality conventional oil with additives to support things like turbochargers, and quality filters, is all you need. The only issue is changing them more frequently. And stick to manufacturers spec on viscosity. People driving high performance even turbo charged, using quality conventional oil will easily get up too 300,000 km if maintained.

    • Contrary to conventional oil, a full synthetic oil breaks down much more slowly and has consistent lubrication properties throughout its service life. It is also less prone to sludge buildup and more resistant to heat. In a turbocharged application, your car needs this heat resistance to prolong the life of the turbo components. It’s best to follow the manufacturer’s recommendations if the manual calls for synthetic oil.


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