Please note this thread has been inactive for 90 days. For the best results, please start a new thread.
Results 1 to 12 of 12
  1. #1
    Chief Petty Officer cpubud's Avatar
    Join Date
    Jun 2008
    Location
    Silver Spring MD
    Posts
    466

    Default regular motor oil vs marine motor oil

    what is the difference between the two. I always run marine oil and a friend of mine uses regular oil from auto parts stores.his motor is a mercruzer 5.0 inboard outboard. he also runs a fram oil filter from auto parts as well he says it the same as a 305 smallblock chevy .

  2. #2
    Senior Chief Petty Officer
    Join Date
    May 2004
    Location
    UK
    Posts
    760

    Default Re: regular motor oil vs marine motor oil

    Im no expert on oil but its down to additives. Car oils to my knowledge dont contain rust inhibiters, they can contain less zinc dialkyl dithiophosphate as cars run less load. This is a good chat about oil http://www.carbibles.com/engineoil_bible.html.

    Basically the ingredients/addetives that make a very good oil are expensive which is why you cannot get cheap oil with the same properties as an genuinely expensive oil. You can obviously pay alot for a cheap oil but you cant get a good oil cheap.

    Cheers

  3. #3
    Moderator Bondo's Avatar
    Join Date
    Apr 2002
    Location
    The Mouth of the Chaumont River, Ny.
    Posts
    52,594

    Default Re: regular motor oil vs marine motor oil

    Ayuh,....

    I guess you didn't bother trying this question in the Search function,....

    Here ya Go,... This has the Absolute Answer to your questions,....

    The Biggest Difference between Marine rated motor oils,+ Any other oils is Marketing.....

    Your motor will run Just Fine,... For a Long Time,...
    If fed a steady clean diet of Any motor oil you can buy off the shelfs of your local WallyWorld.....

    Now,.... Let the War begin,.........
    Any Grease is Better,..... Than No Grease at All.......

  4. #4
    Chief Petty Officer
    Join Date
    Jun 2008
    Posts
    636

    Default Re: regular motor oil vs marine motor oil

    For 23 years,my I/O has had nothing but Pennzoil 30wt and a cross referenced filter from the auto section used on it. It still runs like new.

  5. #5
    Chief Petty Officer
    Join Date
    Jun 2008
    Posts
    636

    Default Re: regular motor oil vs marine motor oil

    double post...

  6. #6
    Lieutenant Commander
    Join Date
    May 2007
    Posts
    1,704

    Default Re: regular motor oil vs marine motor oil

    Quote Originally Posted by Bond-o View Post
    Ayuh,....

    I guess you didn't bother trying this question in the Search function,....

    Here ya Go,... This has the Absolute Answer to your questions,....

    The Biggest Difference between Marine rated motor oils,+ Any other oils is Marketing.....

    Your motor will run Just Fine,... For a Long Time,...
    If fed a steady clean diet of Any motor oil you can buy off the shelfs of your local WallyWorld.....

    Now,.... Let the War begin,.........
    Agreed! biggest issue is making sure you use something in the right range of viscosity, etc... and change it! Cheap oil will work fine in most cases IF you change it.

    Note that if youre oil pressure is getting up there, the fram oil filters may not do the trick... they filter better than a typical marine filter, but don't flow as well. Good filters with good flow are best, but if you're changing oil regularly and not ragging on it too bad, your probably just fine with auto filters.

    That's not what I do, but the truth is that most decent quality oils will work fine.

    I will say that especially for older engines (with flat tapet camshafts) or newer ones built more agressively for performance - especially if running a hydraulic lifted cam should be run with a good detergent package and additives that have very good antiscuff properties. It will make a substantial ditterence in the lifetime of the engine and greatly reduce the chances that you'll round off a cam lobe (or lobes)... I know that someone has a brother ran cheap crap oil in their race car engine for 37 years and the bearings looked like brand new after 217,000 miles, etc... some people smoke 3 packs a day and never have any ill health effects, but it's usually not my luck to get off that easy. I spend the extra money to run good oil, and i do know a little bit about what goes into oil formulation.

    I currently run Shell Rotella T (hydraulic flat tappet cam). The offroad version has those nasty anitscuff additives that are sooo helpful for greay iron wear prevention but were phased out of automotive oils some years ago (bout the time all the major manufactures went to roller cams, etc..) and are being phased out / replaced even in diesel oils now. After a significant break in period I'll switch to full synthetic with a racing / offroad additive package. I need to do a little homework to be sure which one since a number of them are changing these days. My engine builder said any of the brand synthetics except mobile one would be fine.

    For regular use, run any decent brand in the correct viscosity, check and change it often, and you'll be fine...

  7. #7
    Moderator achris's Avatar
    Join Date
    May 2004
    Location
    I come from a land down-under...Perth, Australia
    Posts
    15,098

    Default Re: regular motor oil vs marine motor oil

    FWIW,

    I have my boat and my car to supply oil to... I did a whole pile of research and I run a high quality 15W40 diesel oil in both. I wanted to run the same in both engines if I could. That way I don't have 2 barrels of oil kicking around, just the one. But I do use genuine filters on the boat... and a generic Z-24 on the diesel.

    Chris........
    The world takes on a whole new perspective when viewed from 100' below...



    1972 Bertram 'Bahia Mar' 20
    2006 Mercruiser 4.3MPI (0W617679) w/Alpha 1 Gen II (0W829301)
    **
    Please don't send service questions in private messages. That's what the forum is for. Messages of thanks, always accepted.
    **
    Member of the month - April 2013. http://www.iboats.com/blog/achris-member-of-the-month/

  8. #8
    Rear Admiral Fishermark's Avatar
    Join Date
    Oct 2003
    Location
    Pt Charlotte, Florida
    Posts
    4,603

    Default Re: regular motor oil vs marine motor oil

    Let the games begin!

  9. #9
    Fleet Admiral HT32BSX115's Avatar
    Join Date
    Dec 2005
    Location
    WA
    Posts
    7,798

    Default Re: regular motor oil vs marine motor oil

    Quote Originally Posted by cpubud View Post
    what is the difference between the two. I always run marine oil and a friend of mine uses regular oil from auto parts stores.his motor is a mercruzer 5.0 inboard outboard. he also runs a fram oil filter from auto parts as well he says it the same as a 305 smallblock chevy .


    GAWD! does this ever stop? (^ cpubud....don't take this personally...it's not about you!!^^)


    I don't make oil suggestions anymore. just do a search and you'll NEVER get a definitive answer!!

    In answer to your question though, I have an answer.....that is, you can read the following and draw your own conclusions.

    Now REMEMBER, all the information below DOES NOT include ANY testimonial information........

    That is, no ones uncle, dad, brother, pet-mechanic, friend, diesel mechanic, idiot magazine article editor, or anyone else (who has no idea what they're talking about, contributed to the information)

    It's is just the facts produced by the industry. Every thing there is verifiable



    http://www.nmma.org/certification/pr.../oils/fc-w.asp



    Cheers,


    Rick


    oh and btw, if everyone did what DonS suggests, I.E. run what ever you want, but change it regularly, they would probably never have an oil related problem....
    73 de Rick
    ----------------------------------------------------------------------------------
    I use xxx oil and have never had a problem........
    1987 FourWinns 211 Liberator, 7.4L- Bravo III installed by ME,
    Formerly OMG 460 King Kobra powered
    1947 Stinson 108-2 Station Wagon
    , Franklin 6A-335B. Hartzell CS 2-blade prop
    -
    All PM's cheerfully answered! Please ask tech questions in the appropriate forum so everyone's included

  10. #10
    Petty Officer 1st Class Liquid_force's Avatar
    Join Date
    May 2003
    Location
    Lawrence, KS
    Posts
    294

    Default Re: regular motor oil vs marine motor oil

    that fc-w certification seems to be aimed primarily at 4 stroke OB's.

    Cpubud - it IS just a 305 GM block, probably specifies an straight 30 weight oil. I would agree that any widely available oil will work perfectly.
    If there are truly advantages to buying the OEM oil they are minimal. Definitely not worth it to me - maybe it is to you.

  11. #11
    Fleet Admiral HT32BSX115's Avatar
    Join Date
    Dec 2005
    Location
    WA
    Posts
    7,798

    Default Re: regular motor oil vs marine motor oil

    that fc-w certification seems to be aimed primarily at 4 stroke OB's.

    Well not exactly, but it IS aimed at engines that are exposed to a (salt water) marine environment.
    NMMA wanted to spec an oil that would be best for engines that are left in salt water when not in use.

    If you keep your boat in the garage when not in use, you can probably use the oil of your choice with good results....(oh no!...... here i go!....some body stop me!!!)
    73 de Rick
    ----------------------------------------------------------------------------------
    I use xxx oil and have never had a problem........
    1987 FourWinns 211 Liberator, 7.4L- Bravo III installed by ME,
    Formerly OMG 460 King Kobra powered
    1947 Stinson 108-2 Station Wagon
    , Franklin 6A-335B. Hartzell CS 2-blade prop
    -
    All PM's cheerfully answered! Please ask tech questions in the appropriate forum so everyone's included

  12. #12
    Lieutenant Commander
    Join Date
    May 2007
    Posts
    1,704

    Default Re: regular motor oil vs marine motor oil

    just for the record...

    My points about oil additives and in particular about what's important for gray and ductile iron wear (ie. especially relevant for flat tappet hydraulic cam and lifters, etc...) are based on peer reviewed journal articles from the engineering literature. Information on additives comes from a combination of trade rags, epa reports, industry news and when I'm curious about something specific crossreferencing company products, claims and msds sheets with patents and references from the peer reviewed chemical literature... I don't know exactly which is better, etc... but i do the homework to verify / learn more from what engine builders, etc... tell me. bottom line, synthetics last better against breakdown at high temp, high quality diesil oils - like Rotella T - are designed ot carry a much higher soot load, neutralize acid better and have the highest concentration of additives that provide anti-scuff properties... which brand is better? heck I don't know, but some certainly are much better dependin on the application and how you define "better"...

Similar Threads

  1. Synthetic vs Regular oil in 1963 Merc
    By trob445 in forum Mercury & Mariner Outboards
    Replies: 5
    Last Post: May 29th, 2005, 02:03 PM
  2. Marine vs. Regular motor
    By Fish Regulator in forum Mercruiser I/O & Inboard Engines & Outdrives
    Replies: 20
    Last Post: November 20th, 2004, 02:22 AM
  3. What the difference between a regular vs. a commercial motor.
    By vaughneric2000 in forum Johnson & Evinrude Outboards
    Replies: 3
    Last Post: July 17th, 2004, 09:07 PM
  4. sintetic or regular oil,whats better for an old motor
    By Max7 in forum Johnson & Evinrude Outboards
    Replies: 4
    Last Post: November 8th, 2002, 03:34 PM
  5. truck motor vs marine motor
    By IOWA BOATER in forum Non-Repair Outboard Discussions
    Replies: 2
    Last Post: April 11th, 2002, 05:20 PM
  1. iboats Forum Directory - Over 100,000 forum posts organized by topic