regular motor oil vs marine motor oil

[cpubud]

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 .

 

[cmyers_uk]

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

 

[Bondo]

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,.........

 

[xxxflhrci]

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.

 

[xxxflhrci]

Re: regular motor oil vs marine motor oil

double post...

 

[wca_tim]

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,.........

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...

 

[achris]

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........

 

[Fishermark]

Re: regular motor oil vs marine motor oil

Let the games begin!

 

[HT32BSX115]

Re: 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 .

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/programs/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....

 

[Liquid_force]

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.

 

[HT32BSX115]

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!!!)

 

[wca_tim]

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"...