Does engine oil burn off at different rates?
Results 1 to 10 of 10

This is a discussion on Does engine oil burn off at different rates? within the General Maintenance, Troubleshooting & Accidents. forums, part of the Tech & Modifying & General Repairs category; I have a question regarding the oil in my wife's '07 Outback. 5000 miles ago, for the first time since ...

  1. #1
    Registered User Soobvirgin's Avatar
    Join Date
    May 2012
    Location
    San Diego
    Posts
    785

    Does engine oil burn off at different rates?

    I have a question regarding the oil in my wife's '07 Outback. 5000 miles ago, for the first time since buying the car (used, about 5 years ago), my wife took her Outback for a service to somewhere other than a Subaru dealer. It's out of warranty and she'd heard of someone who specialized in Japanese cars. He told her that the 5w30 oil that Subaru use is terrible and he would put something much better in instead. Tonight, my wife asked me to check the engine oil level. It was below the empty level on the dipstick, but just barely registering something. This car has never burnt through oil before, so I looked under the car, expecting to see a leak but, nothing. I went to the store and added 2 quarts of semi-synthetic 5w30 and that topped it off, so I guess it can't have been completely empty.

    My wife showed me the receipt from the guy who serviced her car and it says he used 20w50 oil. So, my question is, would using such a different weight of oil from the manufacturers' recommendation cause it to burn off so quickly? Or is it more likely something is wrong with the car? She's gonna' take it back to the same guy tomorrow to have him check it out, but I'm curious to hear opinions from people who aren't taking money from me/my wife. Thanks.

  2. Remove Advertisements
    ClubWRX.net
    Advertisements
     

  3. #2
    He simply abides. SD_GR's Avatar
    Join Date
    Jul 2002
    Location
    CA, US
    Posts
    21,915
    I Support ClubWRX
    Oil use is not linear and does vary with type, brand, and viscosity. Use can be most at the end of an interval or the beginning or in spurts depending on how it's driven.

    Since the Subaru oil is not terrible regardless what oil Subaru actually used (no major oil is inadequate) I'd suspect he simply added less and misread the dipstick.

    Leaks on the other hand are linear; see if the filter is ok and also the drain plug.
    WRX Info Links, Courtesy TheJ
    The world breaks everyone and afterward many are strong in the broken places. Ernest Hemingway
    I lied. I cheated. I bribed men to cover the crimes of other men. I am an accessory to murder. But the most damning thing of all... I think I can live with it. And if I had to do it all over again - I would. Benjamin Sisko
    DISCLAIMER: Opinions expressed are the author's alone and are inherently worthless.

  4. #3
    Registered User Soobvirgin's Avatar
    Join Date
    May 2012
    Location
    San Diego
    Posts
    785
    Thanks. I did look under the car last night and didn't see any sign of oil, although I couldn't get far enough under to see the filter or sump plug. I've seen no oil marks in the driveway and my wife parks in the same spot at work every day and has seen no sign of oil there either. That's what's making me wonder if it's burning this oil off because it was a different viscosity. But yes, it's also possible it wasn't filled fully when the last oil change was done.

  5. #4
    Registered User cogito's Avatar
    Join Date
    Jul 2013
    Location
    Southern NH
    Posts
    291
    On the safe side you can put cardboard under the car. It's worked for me on hard to spot surfaces. Also I had switched from motorcraft to Mobil 1 on my last vehicle and noticed significant burning ... and quickly returned to motorcraft. So not all brands are equal. That being said, I've had zero issues with Subaru oil, but still carry a quart in my car care package just in case.
    2013 WRX Dark Grey Hatch
    1974 Datsun 260z Stroker

  6. #5
    Moderator Donkey's Avatar
    Join Date
    Apr 2005
    Location
    Da boonies
    Posts
    5,853
    I Support ClubWRX
    A 5w30 would burn off WAY faster than a 20w50. You do understand how "thick" of an oil a 20w50 is yes?
    Resident Adviser @ WTF Tuning, LLC
    2002 FORESTER S
    1998 FORESTER S




  7. #6
    Registered User Soobvirgin's Avatar
    Join Date
    May 2012
    Location
    San Diego
    Posts
    785
    Quote Originally Posted by Donkey View Post
    A 5w30 would burn off WAY faster than a 20w50. You do understand how "thick" of an oil a 20w50 is yes?
    Not really. I don't know much about oil. But the mechanic who serviced my wife's car did say that he was using a thicker oil because it was better for the engine.

    She took the car back to him this afternoon. He found no sign of a leak under the car anywhere. He also said that it was strange because all his customers comment on how much less oil their cars burn on this viscosity. So, it was time for an oil change anyway and he's put the same 20w50 back in. I leave my wife to maintain her own car, but it looks like I'll have to check the oil more frequently. Thanks for the responses.

  8. #7
    Master Baiter EJ257's Avatar
    Join Date
    Aug 2007
    Location
    On a stream bank somewhere
    Posts
    19,518
    I Support ClubWRX
    Quote Originally Posted by Soobvirgin
    Not really. I don't know much about oil. But the mechanic who serviced my wife's car did say that he was using a thicker oil because it was better for the engine.

    She took the car back to him this afternoon. He found no sign of a leak under the car anywhere. He also said that it was strange because all his customers comment on how much less oil their cars burn on this viscosity. So, it was time for an oil change anyway and he's put the same 20w50 back in. I leave my wife to maintain her own car, but it looks like I'll have to check the oil more frequently. Thanks for the responses.
    There are companies out there that will test the oil for you to determine how well the particular car is taking the oil (e.g., Blackstone). It's something like $20 for a used-oil analysis (UOA). Honestly, I'd trust hard data over what a wrench monkey (nothing against your mechanic) says any day of the week...
    2005 WRX STi (Mods | Virtual Dyno)

    Resident Tuner @ WTF Tuning, LLC

    "Never trust anything that bleeds for a week and lives ..."

    UNYSOC

  9. #8
    He simply abides. SD_GR's Avatar
    Join Date
    Jul 2002
    Location
    CA, US
    Posts
    21,915
    I Support ClubWRX
    The 20W won't pump cold as well as the 5W in cold weather. I also wonder about heat -- which oil generates more and which absorbs or transfers more. If winter exists in your area consider a 5W or 10W next time. The factors to balance are wear, consumption rate, heat generation via friction, heat absorption, cold pumping, viscosity stability over the lifetime, resistance to oxidation, cost, and availability. That said it's not easy to find a truly bad oil so you can just forget about all the pedantic stuff etc too if you chose.

    Anyway watch the level very closely and see what happens.
    WRX Info Links, Courtesy TheJ
    The world breaks everyone and afterward many are strong in the broken places. Ernest Hemingway
    I lied. I cheated. I bribed men to cover the crimes of other men. I am an accessory to murder. But the most damning thing of all... I think I can live with it. And if I had to do it all over again - I would. Benjamin Sisko
    DISCLAIMER: Opinions expressed are the author's alone and are inherently worthless.

  10. #9
    Registered User Ingo's Avatar
    Join Date
    Mar 2012
    Location
    Colorado Springs, CO
    Posts
    1,110
    ^ Key is to watch the oil level. There is NO oil that could be worse than NO OIL! Running out of oil is instant and major death for any engine, bad oil is just premature (unnecessary) wear.
    You can't have everything - where would you put it?

  11. #10
    Registered User Soobvirgin's Avatar
    Join Date
    May 2012
    Location
    San Diego
    Posts
    785
    Quote Originally Posted by EJ257 View Post
    There are companies out there that will test the oil for you to determine how well the particular car is taking the oil (e.g., Blackstone). It's something like $20 for a used-oil analysis (UOA). Honestly, I'd trust hard data over what a wrench monkey (nothing against your mechanic) says any day of the week...
    Yeah, I agree. Although, this guy has Asperger's. These people tend to be incredibly smart in one particular field and know everything about it; this guy's is clearly cars. So, I trust that he knows what he's talking about, but yes, an oil analysis might be a good idea. For now, I think I'll just monitor the oil level more frequently and see what happens. If the problem continues I'll look into it. I might jump on it for my car but, for my wife's... meh.


    Quote Originally Posted by SD_GR View Post
    The 20W won't pump cold as well as the 5W in cold weather. I also wonder about heat -- which oil generates more and which absorbs or transfers more. If winter exists in your area consider a 5W or 10W next time. The factors to balance are wear, consumption rate, heat generation via friction, heat absorption, cold pumping, viscosity stability over the lifetime, resistance to oxidation, cost, and availability. That said it's not easy to find a truly bad oil so you can just forget about all the pedantic stuff etc too if you chose.

    Anyway watch the level very closely and see what happens.
    Well, it can get down to 23 here, but never stays below freezing once the sun comes up. But summer lasts an eternity and often hits 110.


    Quote Originally Posted by Ingo View Post
    ^ Key is to watch the oil level. There is NO oil that could be worse than NO OIL! Running out of oil is instant and major death for any engine, bad oil is just premature (unnecessary) wear.
    Haha, agreed.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •