Regular Oil vs Synthetic Oil -EricTheCarGuy

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Lately I’ve been seeing a lot of posts over at the forum talking about switching to synthetic oil with less than ideal results. Instead of typing out the same answer over and over I thought I would make this short video to help explain my experiences with synthetic oil. I’m not saying synthetic oil is bad, in fact it has it’s place but my opinion is that place is not in your 15 year old Toyota or Chevy. The reasons as explained in the video are that synthetic has different flow characteristics and can actually cause your engine to leak oil and run noisy. It’s perfectly OK to run conventional oil of the correct viscosity and change it on a regular basis. You don’t need to spend the extra money on synthetic oil if your owners manual does not call for it.

I look forward to your comments on this.

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Discussion about this video:

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Author: Rafael


32 thoughts on “Regular Oil vs Synthetic Oil -EricTheCarGuy

  1. I got 2005 4Runner that I bought brand new with 100 miles on it, been using regular oil because the owners manual says nothing about synthetic and the dealer always gave me regular oil when I used to get my oil changes at the dealer. My 4Runner has 217,000 miles on it and it has no issues at all and runs great. Only thing I do is stay on top of my oil changes and get it done when it's that time. My 2015 Prius requires Synthetic so I use it.

  2. To me it’s preference and depends on your car, make and model. Be it Lexus or Ford or Nissan or BMW. Cars react differently based on several factors. Oil won’t Cause leaks but, certain oils like Eric said will escape gaskets/seals more than others. Depends on the upkeep of your car. Wear and tare etc.! How my car or yours reacts to the same oils depends. Nobody is wrong or right. As long as you’re using the correct oil viscosity stated by manufacturer for your car, it’s right.

    I use what recommended. Conventional oils are great and are changed more often But, as long as oil is changed properly when it should be( every 3000-5000 miles conventional) or (every 7000-10000 Full Synthetic) it’s fine. Some miles allowed may be higher. Eric’s opinions include some facts. Every mechanic is different but his advice is sound.

    He gives advice for free. We’re fortunate because this wasn’t available 30 years ago. We’ve so many choices to pick from. Let’s be grateful we’ve options and realize if it doesn’t work we can find an oil that does.

    Mobil 1 for me. Some prefer Other brand names. None are bad choices if your car agrees with it. Strangely, what works for one car may not yours/mine.

  3. I have an 03' Grand Am GT. I went from Conventional oil
    to Synthetic when I got it. But I knew Synthetic oils have
    a tendency to "slip" through plugs, and gaskets. What I
    did was, go to a HEAVIER synthetic oil, than that which
    I had with the conventional. Works just fine. And you can
    actually MIX two different viscosities. Or, in the Winter
    Months, I will have 3 qts. of a thinner viscosity—one qt.
    of the standard viscosity. When Summer comes, I go
    Back to a heavier viscosity. Sounds like a lot of trouble,
    but when you can change your oil with your EYES closed,
    and also get your oil with GREAT discounts—Why NOT?

  4. Although we frequently hear about synthetic oils allowing longer oil change/service intervals, a longer service interval is not necessarily an advantage. Oil routinely takes in micro-grit from the huge volumes of air demanded by most engines, and dirty engine oil more readily wears engine parts. In addition, engine oil accumulates water and creates acids which are not always completely burned off during normal operations. As Eric suggests, every car operator must decide the oil change interval based on driving conditions, and as long as the oil meets OEM / API specifications and is still clean enough to use, the type of oil, itself confers no advantage.
    Good video on a tough question, and I subscribed.

  5. After the results from synthetic oil in piston aircraft, I learned to NEVER put synthetic oil in engines run only occasionally. Daily use? Great? Occasional use? Conventional ONLY!

  6. Hi EricTCG. I was wondering if it would be wise to use conventional 5W-30 on a small 2 cylinder Briggs and Stratton engine? Would it be too thick for this type of motor? I just drained all of the old, black used engine oil out of that 2 cylinder engine and I am thinking of using the 5W-30 conventional oil in that engine. Someone gave me a lot of that 5W-30 new oil and I want to use it up. What are your thoughts on this?

  7. my Toyota Tundra is 20 years old, has 240,000 miles on it, and I've run Mobil 1 since day one. The engine runs like new to this day, doesn't burn or leak a drop of oil. I also run it all my motorcycles, (only 10/40 15/50 without the friction modifiers) . I've taken apart many engines that were run on dino oil….all black and scarred…the ones that were run on full synthetic had metallurgical failures, but all of them looked nearly new inside. I will never run petroleum.

  8. I assume that most if not all new vehicals made have a Group lll oil put in at the factory and that when they print up the owners manual they take it for granted that the owner uses a group lll (synthetic oil) with the recommended typ and vicosity. Whether a Group l or Group lV (Full/100% Synthetic Oil) they are ALL GOOD OILS! as long as they meet the API Standard required for your car.

  9. Thanx Eric-Always Used Conventional Oil on the Family Toyota Camry (4cylinder) with Only 48k Miles on it and drive the car twice a week around town for ‘Near Errands’ -Should I or Should I NOT Switch Over to ‘Mobil 1’ Full Synthetic Oil to Further Preserve the Motor in NYC Very Cold Winter (We All Commute to the City and do Not Start the Car Everyday…,And the Car is Sitting Outside; all the Time.., Thanx Eric (Just Don’t want to Do more Damage to Motor and keep it for over150k Miles

  10. Oil is oil as long as it's API approved. I've been running cheap oil for over 20 years all different kinds of brands. But mostly super tech oil from Walmart it's all the same if you ask me. To each their own

  11. Hi Eric, saw your video after the I changed my oil. I purchased a 2003 Honda Accord 3.0 V6 3 weeks ago. I recently got oil change and I used synthetic oil, I did notice there is a slightly louder engine noise (knocking/clicking sound). So should I go back to regular oil the next oil change? a mechanic told me once i used synthetic oil I need to stay with synthetic from now on. the mechanic also told me to buy Lucas heavy duty oil stabilizer to help reduce the engine noise. what do you think?

  12. Synthetic is more a marketing gimmik not a standard. If Viscosity index (VI) exceeds 150 then it is called synthetic oil. It could be any type of oil passing that criteria

  13. Spot on. Bought a1999 Suzuki vitara had no leaks till I changed the oil to synthetic, within 100 mi , my oil pan started leaking like crazy, switched back to Dyno oil it’s much better but still leaking 😭. The pan is a total pain in the ass to take off( have to remove the front diff. ) ain’t doing that , so now I park it in the street and add 1 qt every 1000mi😂.

  14. Conventional oil is as good as synthetic. Synthetic can stay in longer. Who says so? NewYork taxi testing says so. Google it and see no more wear on the engines by using conventional or synthetic.

  15. I used Castrol GTX 10 40 in my Nissan PU and changed it regularly. 320k mi later the engine only needed a camchain and valve job. Inside of valve cover was clean.

  16. The points he made are: 1) Follow your manual. 2) Brands don't matter as long as they conform to the specifications and standards as set out by API.
    Now that is a conclusion I can live with.

  17. Eric, I have a 2004 Toyota Sienna with 328k mi. I use Quaker State conventional 5w/30. I change both at 7500 miles religiously. I'm going to try Super Tech full Synthetic 5w/30 on my next chg with the Fram Syntheticfilter.. My only goal is to push oil chg interval to 15k. Looks like it will cut my annual oil cost 75% and filter cost will be abt the same.

  18. Hey there Eric my owners manual says to use “Mitsu” engine 0w20 full synthetic. But if you do not use their brand to use a 5w20 grade oil. Why would that be?

    Can I get away with using a 5w20 semi?on a 2019 Mitsubishi Mirage. Also I plan to change it out every 3000 old school or is that over kill it’s Sunoco ultra synthetic blend I plan to use. Also I live out in Phoenix

  19. Sorry dude. Switchig to synthetic does not cause oil leaks. Quite spreading myths to people. Specially if you are claiming to edcuate. Credibility aas zero 65 seconds in

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