Diesel Oil

[candycat]

Can anyone tell me if there is a shelf life on diesel oil?
Thank you

[robw_fl]

Not sure about the shelf-life of the oil itself, but if it's old it can have any number of problems that can cause trouble.

Depending on the conditions it is being stored in, possible use of additives or fuel treatments, level of fuel in the tank it's been sitting in... the useful life can certainly vary.

Best answer to your question I think: If you're worried about it - polish it, or get rid of it and put in fresh (And preferably clean the tank if possible). If for some reason that's not possible - time to stock up on your filter supply....

Rob

[GordMay]

Yes.
See ➥ http://www.cruisersforum.com/forums/...uel-29071.html

[zeehag]

my yanmar man said change it every or every 100 hours whichever is first.
as far as in the bottle---forever. once poured one yr. we found 100 hours was every 2-3 months cruising, depending on storms and tight places and icw.

[Healer52]

The oil in the engine? Every 100 hours or so. The diesel fuel itself? Keep it clean and dry, and it will last for quite a long time (I know of some that stayed on-spec, verified by an Air Force Fuels laboratory, after being buried in a tank for over 50 years).

[robw_fl]

Guess I should have asked which oil they were referring to. 'Diesel oil' sounds more like 'Diesel fuel' to me than 'Engine oil.' But yes, good points above regarding both.

So... which one are you referring to? And what exactly is bringing on the question?

I mean, when you say 'shelf life' - do you really mean in the jug, unopened on the shelf? Or 'shelf life' in the fuel tank/oil pan (depending on which oil you're asking about) - these are two entirely different situations.

Frankly, I think the answer is going to be the same as I gave above regardless. If you think it's old, unless it's a huge quantity for some reason... why bother with it? If it's old engine oil in your engine, change it. Old fuel, polish it or change it out. If it's really just sitting on the shelf 10 years new... hell, it's probably fine.

[nico105]

Helo all, I a currently underway and have Rotellata T SAE 30 in the Yanmar. I have aquired a gal of Rotella T 15W 40. I am planning on leaving the Skull Crk Marina this am.

Can I mix these 2 oils types in my Yanmar 3gm30? I will be getting a lift into town for a new gps ant. and SAE 30 if it is a bad idea to mix these two oils, both Rotella T...

Thank you, David on the s/v Nico

[Pblais]

The 15w 40 is probably a better choice for your engine in any case. While I don't see danger in mixing them, I don't see the point of not changing the 30 out and starting fresh. I'm also not clear why you would need to mix them? If your oil is too low then why? I don't find I need to mix oils unless You just wanted to top it off.

If the old oil is inside the engine it will absorb moisture. Old well used oil in the engine contains acids generated from the heat of the engine. Leaving old use oil in the engine isn't good for it as the acids do what acids do. New oil still in the container has a long shelf life and I'm not sure there is a limit. It's pretty stable stuff new and in the container.

[sailingmonica]

Originally Posted by Healer52

The oil in the engine? Every 100 hours or so. The diesel fuel itself? Keep it clean and dry, and it will last for quite a long time (I know of some that stayed on-spec, verified by an Air Force Fuels laboratory, after being buried in a tank for over 50 years).

Yes, but they don't make anything anymore as good as they used to 50 years ago, and that includes fuel, so perhaps one tenth that is more like it nowadays.

[Tellie]

Originally Posted by nico105

Helo all, I a currently underway and have Rotellata T SAE 30 in the Yanmar. I have aquired a gal of Rotella T 15W 40. I am planning on leaving the Skull Crk Marina this am.

Can I mix these 2 oils types in my Yanmar 3gm30? I will be getting a lift into town for a new gps ant. and SAE 30 if it is a bad idea to mix these two oils, both Rotella T...

Thank you, David on the s/v Nico

I'm more than a bit anal about diesels so don't be offended. Oil is the LIFE BLOOD of any engine. But not being able to decide if it's safe to mix two different weights of oil sounds like you're being a bit cheap. Just change the oil and don't mix. There's very little chance mixing will cause any problems if you regularly change your oil but why risk even a slight chance for the very little relative cost of new oil and filter? Just remember the basic three C's of diesels, Clean air, Clean fuel and Clean oil.

[nico105]

Originally Posted by Tellie

sounds like you're being a bit cheap.

It has zero to do w/ cheap or not cheap. What is has to do w/ is what is available. I was disappointed in the Skull Crk Marina's Ships Store. I screwd up on my departure by not having enough Rotella T SAE30! My fault. This is why I came here, again, to post a question about Cruising, which is what is happening. Cheap...that's funny.
David
s/v Nico underway to the Chesapeake Bay/Mobjack Bay...

[Tellie]

Originally Posted by nico105

It has zero to do w/ cheap or not cheap. What is has to do w/ is what is available. I was disappointed in the Skull Crk Marina's Ships Store. I screwd up on my departure by not having enough Rotella T SAE30! My fault. This is why I came here, again, to post a question about Cruising, which is what is happening. Cheap...that's funny.
David
s/v Nico underway to the Chesapeake Bay/Mobjack Bay...

Like I said in my first response. I'm a bit anal about diesels so don't be offended. Diesel engines are hard on oil, marine diesels especially because of the nature of their use. Mixing oil weights will give you an oil weight somewhere inbetween the two weights mixed. The real no no would be to mix oil from two different manufacturers. But since both are Rotella in your case the consensus seems to be no big issue. Personally I'd change it all out to the available 15-40 but that's just me.

[S/V Illusion]

It would be nice if candycat came back to clarify what he intends by the term "diesel oil" as everyone here had to presume lube oil or fuel. Excellent example of vague question yields little info.

[nico105]

Tellie, I'm not offended...and intend to change out oil and filter sooner than later. I appriciate what you have said here, this forum is a valuble resource.
@S/V Illusion, my question was for Lube oil, not fuel. I should have clarified and next time not add to the vaugeness of the oil post. Sorry. I took the tread to mean what i was speaking of, lube oil.
Thanks for the input guys...David

Thanks Guys, David, S/V Nico

[DeepFrz]

nico105, next time it would be better to start a new thread instead of hijacking one already started.