Top 7 Urban Legends About Motor Oil Member, Administrator, Moderator Posts: 10,315
edited September 2014 in General

imageTop 7 Urban Legends About Motor Oil

Urban legends, lies and distortions surround oil changes and engine oil use. We bust the myths and reveal the truths about the top seven urban legends about oil.

Read the full story here


  • grassmanfivegrassmanfive Member Posts: 1
    I worked 20 years at the biggest trucking co. in the us as a diesel mechanic , and we had to change transmissions and differentials on a frightening high rate until we started using synthetic gear lube, after that we nearly had to close the rebuild shop because we didnt have the business. Also we started using synthetic blend motor oil and doubled the oil change interval to 25000 miles, that's not a typo, we also went from 350,000 trade in intervals to over 1,000,000 trade in interval ask Yellow freight i have been retired since 95 so some things could have changed but I'm telling it like it was
  • 16tons16tons Member Posts: 1
    I worked for many years in the Marine industry as a Marine Engineer and as Project Manager for Ship Repair and new installations. I have also written dissertation on the 'oil change interval' myth. We change our engine oil far too often. The only true way to determine oil change frequency is to send it out for oil analysis. One vessel I served on, only had it's engine oil changed once per year (and only because they thought it was the right thing to do) even though the oil analysis came back certifying the oil as fine. These engines were only turned off once every month or two, for a long weekend to provision the ship.
  • thecardoc3_2thecardoc3_2 Member Posts: 8
    Why did you not advise the readers that in order for the maintence reminder system to work correctly they must use oil that meets the very specific requirements of their vehicle manufacturer? Articles like the one above that do not spell all of details out clearly for the consumer are careless and misleading.

    Some of the reminder systems can allow for a maximum of 18,750 miles (Mercedes-Benz) between services (typical use normally has the system expire around 11K-12K). Failure to use the manufacturers approved oil will result in an engine failure with that system. Which also brings up another issue, in the event that a reminder system is accidently reset even if the correct oil was used, some manufactures specify that servicing should be done at 3000 miles (GM, check your owners manual!).
  • thecardoc3_2thecardoc3_2 Member Posts: 8
    Please coordinate your advice to the readers with this article from the New York Times about engine sludge formation.

    Back when this article made news none of us really knew what was happening and we saw the manufacturers take it on the chin. Today through continuing edication we now know what was really to blame, and it was the oils we were using. It wasn't extended drains, although in some cases that easily may have played a role. It wasn't the engine design changes which were made to reduce emissions, although they did contribute to the issue. Again the fault was with the API and ILSAC oil specifications at that time. In order to educate the readers as you have tried to do here, you must report all of the facts, and not just cherry pick them to your convenience.
  • philip17philip17 Member Posts: 25
    Using the correct oil for your car is essential. In my story I quote an Edmunds Engineering Editor as saying, "As long as the oil meets the service and viscosity requirements set out in your owner's manual, you can switch back and forth (between normal and synthetic oil) as much as you want." Oil requirements are listed in your car's owner's manual along with how often the oil needs to be changed. If your car has a maintenance minder, which lets you know when the oil needs to be changed based on a number of factors, take the time to understand what it is telling you. It will save you money and still ensure your car runs reliably. Thecardoc3 has included a link to a New York Times story on sludge. This is a problem that is avoided by maintaining a car correctly. How widespread is the sludge problem? The article says: "Given the millions of engines in the United States, the number of sludge-related failures is microscopic, said Robert J. Last, vice president of operations at FEV Engine Technology, a consulting firm in Auburn Hills, Mich."
    Philip Reed, Senior Consumer Advice Editor,

    Philip Reed, Senior Consumer Advice Editor

  • thecardoc3_2thecardoc3_2 Member Posts: 8
    ""As long as the oil meets the service and viscosity requirements set out in your owner's manual,"

    Hi Mr Reed.

    If it was only that easy today. We often run into issues where consumers don't comprehend exactly what "the service" portion of that statement really means. For example a new GM automobile that requires 5W30 actually requires an oil with the dexos1 label to be absolutely certain that it meets GM specifications. You can see more about that here.

    It's really getting to be a problem when it comes to proprietary specifications. Oils that meet a Ford (M2C929A M2C930A) or GM specification are actually thinner than the standard 5W30, or 5W20 that meets the API and ILSAC standards for those viscosities. European vehicles that require 5W30 actually require a thicker oil than what meets the API and ILSAC ratings. (See VW 502/504 and 507 specs, BMW LL-01 Mercedes 229.5 etc.)

    There is an eight hour class that I would recommend shops and technicians attend in order to learn why the technology that is in today's cars has caused this drastic change. Again failing to explicitly spell all of this out has the potential to confuse the consumer and lead them to make a mistake when servicing, or having their car serviced.
  • jmonroejmonroe Member Posts: 8,989
    Here is my problem.

    I have an ’05 Hyundai XG 350 (3.5 liter engine) and I have religiously changed oil in it, to the tune of 15 oil changes and it will be 7 years old in April 2012. I’d say that is a lot, way more than what is needed. When I say “I have”, I mean me personally. I always used Pennzoil 10W30 with no problems at all. The car has a little over 43K miles and the engine thru a rod last week while my wife was driving it at about 35 to 40 MPH on a level road. By a very strange coincidence the dealer did the last oil change about a month ago and the windshield sticker says they used Pennzoil 5W20. Hyundai is not honoring their 10 year 100,000 mile warranty because somehow they showed higher mileage when they did service work in March of 2010 and my oil log for the next oil change by me in April 2010, showed less. I’m convinced that their mileage entry was incorrect but I could never prove that because I never noticed the mileage on the service slip I was given at the time of service. Because of this ‘typo’, by someone, they have denied warranty work even though the dealership admits that the engine is “very clean”. I’m in the process of appealing that now.

    Even though I noticed after the dealer did the oil change that the windshield sticker showed the wrong oil (5W20 when it should have been 10W30) I didn’t think it would be a problem at the time. However, now that the engine blew 500 miles later I’m beginning to wonder if this is just a coincidence or did the 5W20 oil cause the problem. Since they are pointing their finger at me, I’d like to point back at them if they are wrong.

    Can anybody out there comment about this?


    '15 Genesis V8 with Ultimate Package and '18 Legacy Limited 6 cyl

  • pacochess72pacochess72 Member Posts: 1
    What oil does your owners manual say to use? Does it say to use a 10w30 or a 5w20? Also, If you can, try and get a sample of oil from your car and send it in to an oil analysis company to see what is what with your oil. You did not drive your car all that much to have a rod go like it did. Also, I did check to see what oil you should use in your car and 10w30 was the right type of oil to use. If they used a 5w20 THEY were in the wrong. Remember, a lot of Hyundai's cars now use 5w20. I think that whoever changed the oil didn't know about the 10w30 oil that was needed for your car or they ran out and they figured oh, it won't make any difference!! Good luck with your claim!
  • thecardoc3_2thecardoc3_2 Member Posts: 8
    5W20 is in fact the correct oil for your car. Hyundai does allow for 5W30, and 10W30 as alternates accordig to Mitchell On Demand.

    Hyundai has up till now typically accepted API and ILSAC standards. Do you have any other repair orders from any other facility that would show mileage on your vehicle during the time in question? How large of a discrepancy are we talking about?
  • bobbymcflybobbymcfly Member Posts: 1
    So, the 'Service Representative' at a VW dealership actually claimed that my first oil change for a new 2012VW Golf should be at 10k miles. Hmm...

    Actually, the first place to look for oil change information should be your owner's manual. For example, in the 2012 VW Golf manual it is stated that a new engine can burn as much as 1 qt of oil per 1.5k miles. Assuming worst case, if you had waited for the 7.5k mile mark or later to change or check the oil, you would have already either been knocking, or would have generated sludge. ~$70 for an oil change compared with the cost of the car ( $20k-30k) is insignificant.

    An important factor is driving distance and style. 10k miles spent by driving 20 minutes each day in city traffic are completely different than 10k miles spent on long 50 minute commutes at 65mph on a highway (or faster). If you actually use your car, why not take care of it with a 3k - 5k mile oil change? Even if you do "waste good oil", I'm absolutely certain that a car engine is many-fold more valuable than all the "good oil" you waste.

    This is all terribly frightening, because the average driver does not question the dealership's advice, and read the full manual before hopping in their car. They then drive it until it's time to take it in for the 10k service. Ten 10k services later, and you're left with an engine full of sludge and no warranty. Time to buy a new car and repeat.
  • carowner1943carowner1943 Member Posts: 1
    The dark motor oil may have to do more with incomplete combustion of gasoline as well as addition of ethanol
    than the ingredients/additives in the motor oil.

    Cars with higher mileage will have a build of sludge
    regardless of the detergents in the motor oil.

    Perhaps oil changes of 3,000 miles with the newer
    hi detergents motor oils may be prudent, but I would
    start changing the motor oil after every 5,000 miles with cars
    over 100,000 to prevent the build up of sludge.
  • shepperdshepperd Member Posts: 1
    Hogwash! Absolute environmental huxterism!The tree huggers believe that extended drain intervals are better for ''mother earth''.What about the environmental impact (not to mention the impact on your wallet) when you have to replace your engine with a new one?I bought a 2000 Chevy S10 with 74k miles and a cracked block.(I replaced the the engine)All due to the former owners changing oil every 10k miles and NEVER changing the coolant!(they were told the coolant was good for 100k miles)You can't change your oil (or other vehicle fluids) too often.By the way, buy oil and filters when they are on sale and learn to DO IT YOURSELF!It's not hard. A trained chimpanzee can do it!
  • 01oldsmobile01oldsmobile Member Posts: 2
    OK firsti tried to write this so everyone can understand, so please bear with me, thanks.... I tell you what, i have a 2001 oldsmobile alero gls coupe with the 3400 V6, well my car is proof that synthetic oil is better and lasts longer, i bought the car 13 months ago, it had 100k when i bought it, i drove the car for about a month and i was averaging 13mpg city and 25mpg hwy, and then my change oil soon light came on, so i reverted to my trusty mobil 1 oil, well i used there best mobil 1 synthetic oil and which says its good for up to 15k miles, and a k&n oil filter i didnt go cheap the filter was about $17 and the oil was $32 for a 5 quart jug, $49 total, so i spent less then most people do at the dealer for their oil change, well anyways i noticed that the car had a noticable amount more of get up and go, and my fuel milage also went up almost instantly, averaging 16.4mpg city and 28.6 hwy, i always ran BP gas 89 octane (10%ethanol), never a drop of premium, so i know that doesn't have anything to do with it, well i kept checking the oil at regular intervals (every other week) at 10K on the oil it still looked brand new, i changed it anyways, and put in the same mobile 1 full synthetic and k&n oil filter, anyways i was changing it every 10k, always looked new, so the last time that i changed it was at 130K and i am now at 144200ish and i feel very comfortable with this oil and filter combo, i would trust it for another 5k.... And we all know how the GM 3100/3400 V6 had that stupid piston "tick tick tick", that for some owners, it started moments after they bought the car brand new and drove off the lot, well my oldsmobile which i know all the records on and it has NEVER had any motor work done, does not to the day go "tick tick tick" and i drive it a lot (of course 45000 miles in a year) and it idles a lot too, and also if i remember right conventional oil breaks down quicker and differently then synthetic oil, and here's the funny thing i've spent $200 for 45k worth of oil (4 oil & filter changes), k.. so the guy that follows his mantenence schedule of every say 4k oil change intervals and whatever oil and filter he chooses, we will say it costs $30 each time for him to change it himself, think its cheaper, not... it would cost him $330 to go the same distance as i did... see my point on awesome synthetic oils? but im not tryin to dog on the fact that automotive maintenence services (dealerships or repair shops), becuase 3000-3500mile or 3 months whichever comes first oil changes is preventative maintenence, especially with conventional oils and cheaper filters.... "Clean oil, Clean engine"... if i had the time to stop every 4k to 6k and change my very good oil and filter, i would... but what im doing now i feel comfortable with, not to mention this isnt my first car/suv that ive done this oil & filter combonation 2006 i bought a 2003 cadillac escalade esv, 6.0L vortec V8, AWD, 11mpg all the time cty&hwy when i got it, (31000 on the odometer), after changing the oil to the best mobil 1 synthetic and a k&n oil filter, i was getting 14.1mpg hwy and 12mpg city, in that big pig i saved some money it now has 251000 and runs great doesnt use a drop of oil, still getting 14mpg hwy and 12mpg city.... also in 2007 i bought a 1990 honda accord 4 door ex fully loaded, pw pl, ext. and a 5 speed manual transmission, i got the car at 185000mi on the odometer same oil & filter as the rest, city mpg went from 23mpg to almost 26mpg, and hwy mpg went from 35.1 to 39.7mpg, now i have almost 300k on the car and it runs great doesnt use any oil and still getting great mpg, and i have done this to a few other cars also, when i chaged the oil was different for each vehicle cause i drove them all differently... so my whole point is that you do pay more money for quality and i honestly think its worth it... thank you again for reading about how well this works for me, and i hope evryone understood it, hope this fixes some of the rumors and questions between conventional and synthetic motor oils....
  • 01oldsmobile01oldsmobile Member Posts: 2
    yes it really does work, but conditions still do very, but i feel safe about this oil, also it does come dont to oil filters too, ive had the best luck with k&n oil filters, but puralator is i think the best if you want to stay under $10 for a filter, and fram is junk, garbage, i wouldnt even be able to count on my hands and feet how many people i know that put one of those frams junk filters on their carsand within2 to 3 days their engines were shot (spun bearings either crank or cam, and twisted piston rods), all because fram filter are way to restrictive on flow, and the cars all varied between 30000 and 200000mi, from 1 year old to 9 years old, they all including me tried getting fram to reimburse us for costs of repair, they wouldnt do it, why do you think that there isnt a single auto maker out there that runs fram from the factory? thanks guys.......
  • gordon942gordon942 Member Posts: 1
    Daily driver 1997 Ford F150 pickup with 4.6 litre engine-4WD-auto that now has 331K miles on it-running errands-occasionally towing a horse trailer, picking up a load of firewood or mulch, picking up our Christmas tree, etc. and I always changed the oil and filter approx every 3-4K miles. Still have good compression-I own a compression tester!-and have never had an issue with the motor. Coincidence?
    Long ago, I bought a 1967 Olds Vistacruiser S/W with 330 engine at 180K and I drove it till I sold it at 320K back to the original owner for the original sale price? Again, changing oil and filter regularly and I did do a valve job-I worked at a NAPA store back then so I did the work-at 275K. It was a daily driver plus I used it to tow a race car. Coincidence?
  • dougdedougde Member Posts: 1
    I worked at a place that made motor oil additive. I replaced oil
    at every 3,000 miles. I took in old oil in to test it for sediment.
    3,000 mile oil had a sediment level over 1%. All that sediment is
    in the oil wearing down the engine. Also acid byproducts of oil
    are neutralized by detergent in the oil which is basic. A change in oil
    is very inexpensive compared to the cost of a new car or engine.
    Therefore I always changed oil at the 3,000 interval and always
    had cars that lasted more than 100,000 miles.
  • alexandergratealexandergrate Member Posts: 1
    "The Mobil 1 44976 Extended Performance 5W-30 Motor Oil is highly recommended.

    It gets great reviews on the web.

    Read more:"
  • chad_bchad_b Member Posts: 1
    2005 GMC Sierra..178,000 miles. The truck runs and drives like new..You couldn't even hear the thing run if it weren't for the 40 series Flowmaster. I use top quality (Royal Purple) synthetic oil and never exceeded 5,000 miles between changes. I'm no tech and definitely no expert but to me the proof of the benefit of using good oil and frequently changing it (along with paying attention to things like trans oil, gear oil and coolant) is right there every time I fire that truck up.
  • garagelady1garagelady1 Member Posts: 1
    I disagree with the oil change recomendations that Edmunds sets forth for newer cars.
    Even Toyota has droppped their recomended intervals from 7500 miles to 5000 miles.
    Remember that most car owners stretch and foget to change their oil at any interval.
    Also the higher the mileage and the less miles driven per year does make a difference in the usage of oil and the longevity.
    Hence the 7800 mile rule is way over . Most car oweners than stretch that to 10000 miles.
    As a garage owner and engine rebuilder for more than 45 years, I can tell you even with the higher quality oils customers are very uninformed as to what oil is even put into their cars.
    And that reguent oil changes still are more than worth the money.

    Most used oil is recycled as our garage does we burn it in a waste oil heater.

    However be sure the garage or Jiffy Lube place you frequent is actually using the correct oil in your car and also be sure that they even change the il filter! Lots of cars come back to us with our oil filter still on the car even though it will have a quick Lube sticker on the windshield!
  • pccstudentpccstudent Member Posts: 2
    I was working for BMW when these long oil change intervals started (using pricy oil also).One thing we found in cars that were going the full 15K before a change was that the oil filter elements were turning to mush (BMW has a canister type filter)you had to clean out the caniater with a rag,the filter was just mush.BMW did fix this problem (this must have been 1998).Today there are problems with oil level indicators getting stuck and people driving low on oil.BMW is a company that does get right on these type of problems so I bet they laid this issue to rest also.
  • pccstudentpccstudent Member Posts: 2
    One issue I forgot to mention.If you want to start a never ending discussion where everyone is an expert (even those that never wrenched professionaly in their life) decide to make the subject of the discussion related to oil.Everyone is somehow,someway an expert on all things oil.
  • yrovyrov Member Posts: 1
    Don't listen to the Blackstone person in (5). I've done (5) to all my cars. The cars still drive like new after many years. The so-called break-in period is extremely important to all new cars to make (5) no myth. FYI, Mercedes-Benz owner's manual actually had one page on what to do in the first 1K miles and recommended service after the first 2K miles.
  • 8aa2ym8aa2ym Member Posts: 16
    These generalizations are good advice.

    Perhaps an emphasis on knowing your own particular car, driving conditions and habits would be advisable. I only drive about 500 miles a month in a high-performance turbo-charged car. Most trips are less than 3 miles. I keep a close eye on her.
  • 8aa2ym8aa2ym Member Posts: 16
    I'd like to see a few of us COMMENTATORS get jobs with Edmunds or form our own group. There is no substitute for being in the field.

    How were these tests run? Where is the data?
  • user3521user3521 Member Posts: 1
    The only thing I like about using synthetic oil is after 50,000 miles or so, the inside of the engine looks brand new, no sludge or oil contaminant color.
  • rickster84rickster84 Member Posts: 1
    I bought a VW Rabbit GTI New in 1984. The oil temp gauge would peg in the red with the dino oil that came in the car. I then switched to a 20w-50 racing oil. It solved the heat problem, but I can tell that it robbed hp. I ran into a guy with a GTI who was running Mobil 1 5w-30 synthetic and he said that cured his overheating problem. I tried it and it did. The car ran cooler than with the racing oil and ran freer. I have been sold on synthetics ever since. I also had a problem with the shifter not wanting to move on days when it was below zero until the car would warm up. I switched to Redline synthetic gear lube oil and it fixed the problem. I could shift the car even on the coldest days before the car is warm. I have since switched to Amsoil, but I swear by synthetics in everything that I own, even the lawnmower. I still have my GTI with over 250k miles with original engine and transmission.
  • dc9mm22dc9mm22 Member Posts: 1
    Oil maintenance minders are a JOKE. My old 2008 Honda Fit sport had this and all it did was go off at a certain mileage. It didn't actually tell if the oil was good or bad just went by miles driven. How do I know this you ask. Because I changed my own oil at 4000 miles and it would sometimes set maintenance minder light off after the oil was already changed, maybe a 1000 or so miles after I had already changed the oil and filter. In other words engine had clean oil in it yet minder went off.

    Oil gets dirty the same way it always did with piston ring blow by. Do new engines alow less piston ring blow by. Hell no. Are oils better, sure but they get dirty just as always. I worked as mechanic at Chevy dealership. We had these government cars and they followed the manual EXACTLY and those engines used to get so clogged up they would eventually spin a rod bearing.Now this was 1989 to around 1994. I doubt engine oil is that much improved since then. Oh we used Pennzoil oil at the dealer.
  • berger_paulberger_paul Member Posts: 1
    I have Mercedes C250 - 2013 year of release. Visiting car maintenance I asked the specialist about the oil they had used. He said it was Everest Euro Line 5W-30 Full Synthetic. After 7000 miles of mileage, I decided to change the engine oil on my own and used this one again. I was surprised but the quality of used oil almost didn't change! the color and viscosity were pretty close to the new oil. Now my car has run 76 miles and I always use Everest EURO LINE. The car runs perfectly! I am satisfied.
  • sfbobfisher1sfbobfisher1 Member Posts: 1
    edited January 2018
    I am looking to buy a 2015 Honda Accord Sport that was pre-owned and a lease. The oil was changed at 3k for first time. second time was 15k and 3rd was 28k. Should this high mileage in between oil changes concern me? The maintenance report shows dates that they were done about 8-9 months. Should this concern me if i'm thinking about buying this vehicle? What should I ask the dealer to find out if they checked this out?
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Ask them to run a CARFAX, or did you do that already? Sometimes a car is serviced outside the dealership, and sometimes it is serviced and not recorded anywhere.
  • isellhondasisellhondas Member Posts: 20,342
    edited January 2018
    Not every shop reports to Car Fax! I know if I owned a shop I probably wouldn't do what ever would be asked of me to do so. I mean....Why?

    A loot of "good" cars are rejected because of some Car Fax comment that scares people away and queers the sale.

    Conversely a lot of unfavorable things don't always show up.

    On balance I guess they are better than nothing. It just has to be remembered that they are not gospel and an ACCCIDENT REPORTED could have been a scratch on the bumper!
  • kyfdxkyfdx Moderator Posts: 227,842
    Maybe so, but there is always another used car to buy, that has a clean Carfax, so why bother with the one that doesn't?

    Plus, if it's a newer car, it will still have that bad Carfax when you go to sell it.. decreasing it's value.

    It doesn't really matter if the information is accurate. It still affects the car's value.

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