marine engine oil

[justinf89]

my volvo penta 8.2L 415hp marine engine calls for full synthetic oil. I've got a question about its oil reasoning.
As listed in the manual

Above 32F: in order
1 volvo penta duraplus sae30
2 synthetic 20w-50
3 synthetic 15w-50

*Multi-weight oils such as 10w30/10w-40 not recommended


Why would it not allow the use of 10w30 if sae30 is called for?
That doesn't matter because I can't get duraplus and it's too expensive.

Wouldnt Pennzoil Platinum 5w50 be better than, say Mobil 1 15w-50 for better flow at startup?

It just doesn't make sense that it calls for volvo full synthetic sae30 then if not, use a 50 weight full syn?

Here's the link, its on page 12 if anybody wants to see for themselves
manual

 

[Steve S]

What is this flow on startup stuff what have you been reading????? A 15w40 or 50 will give all the flow you will ever need at 32*f. A 5w-50 is actually a lesser oil than a 15w40 or 50 due to the viscosity improvers. A car engine has an easy life a marine engine has a severe life. You run Amsoil 15w40 Diesel Marine oil in your truck No? That would be an excellent choice for your boat . It has no viscosity improvers which makes the oil really protect like a straight 40 at the extremes, Also Amsoil makes a 10w30-30 HDEO oil that would also be a good choice depending on the oil pressure and temps under a sustained load.

 

[92saturnsl2]

Originally Posted By: justinf89
my volvo penta 8.2L 415hp marine engine calls for full synthetic oil. I've got a question about its oil reasoning.
As listed in the manual

Above 32F: in order
1 volvo penta duraplus sae30
2 synthetic 20w-50
3 synthetic 15w-50


Clearly they see no need for a winter multi-grade oil in late spring / summer temperatures. A multi-grade oil (synthetic or not) with a wide viscosity rating will degrade faster than one that is closer. There is no need for a 5w or 10w oil in summer temperatures, it will afford you nothing in the way of protection, even during cold starts.

They're probably suggesting 30 weight as an alternative to the Synthetic multigrades since the are no viscosity improvers that can break down.

O/T, What engine is the 8.2L based on? We used to have a Penta 5.7L based on a fuel injected GM small block.

 

[dwendt44]

Some 10w30s are barely 30.
They are on the thin side of the 30 weight range and therefore V.P. warns against them.
Straight 30 is generally thicker, and toward the thicker end of the 30 weight range.
Just my guesstimate; YMMV.

 

[ItsuMitsubishi]

Marine engines work just a little bit harder than your run of the mill 5w20 filled corolla engine and as such durability is a top priority instead of novelties like "cold flow" and 'warm-up fuel economy'. From the choices SAE 30 would be my pick (SAE 40 for heavy duty). A multi grade offers zero protection benefit and much inherent inadequacy by way of VII additives shearing out of grade, oxidizing etc. vs a straight oil. That even applies for the 20w-50 and especially so for the 15w50. If you had a way of knowing, then the product with the least VIIs would be the most suitable. Most dedicated marine mutigrade 40's have the narrowest spread around making them appear odd like 20w40.

 

[justinf89]

The problem is I can't find a Full Synthetic straight 30 weight. Thats why I have to go with a 50 weight i guess since they don't have 40 in the list.

 

[Steve S]

Originally Posted By: justinf89
The problem is I can't find a Full Synthetic straight 30 weight. Thats why I have to go with a 50 weight i guess since they don't have 40 in the list.
What is wrong with Mobil 1 15w50? It would be a great oil. It seems to be a GM 502 engine. What is the problem with the oil choice?

 

[Steve S]

If you go the commercial maritime companies you will find that they used 15w40 in all their gas and high speed diesel boat engines I worked for a company that had them for accounts in the San Francisco bay area.

 

[Steve S]

I am having trouble understanding the problem with the oil. Anybody with a boat with the 8.2 litre Volvo penta in it shouldn't even complain about the price of volvo penta duraplus sae30!!!! I sound like my dad!! It is like owning a Ferrari and complaining about the cost of maintenance. I doesn't really work.

 

[justinf89]

Originally Posted By: 92saturnsl2


O/T, What engine is the 8.2L based on? We used to have a Penta 5.7L based on a fuel injected GM small block.




It's based on a bored out big block 454.

 

[justinf89]

I'm sure I'll just go with the 15w-50. I was just wondering why they say go with a syn 50 weight if you can't use v.p.'s 30 weight syn. I just wanted to be sure I'm getting the best protection. My local Volvo dealer has to order the stuff which I can't believe, so I'm not even going to deal with it.

 

[92saturnsl2]

You can't go wrong with Mobil 1 15w-50.

 

[Steve S]

Originally Posted By: dwendt44
Some 10w30s are barely 30.
They are on the thin side of the 30 weight range and therefore V.P. warns against them.
Straight 30 is generally thicker, and toward the thicker end of the 30 weight range.
Just my guesstimate; YMMV.
All things equal the between the moveing parts in the engine a straight 30 actually protects better than a multi viscosity [Vi improved] oil. Redline Oil had a good explaination sheer between the parts on their website , though it has been quite a while since I have been on the website.

 

[Steve S]

The Amsoil like you use in you in your pickup 15w40 Diesel MARINE would work well in your boat engine. No viscosity improvers so it should protect like close to a straight 40. If you really like to stay with Amsoil.

 

[Bror Jace]

Again with these manufacturers and their not-quite-well-thought-out oil recommendations.

It seems they are OK with straight 30 weights ... but don't like 10w30 (and presumably 0W-30, 5w30, etc …) or even XW-40s. Presumably, they are concerned that these oils, even in “synthetic” form (whatever that means these days) will shear down. I think that’s a concern … but why skip over one of the most common marine oil weights: 15w40 and recommend an XW-50? That makes very little sense.

I agree with Steve S that any multi-viscosity oil is going to give you good cold-start performance in Virginia so no worries there. I would pay more attention to the viscosity at operating temp as well as the oil’s reputation for thinning (look at used oil analysis posted here).

Nothing wrong with Mobil 1 15W-50. If it’s plentiful and reasonably priced. It’s not even a thick 50 weight … typically close to a “45” weight (published viscosity @ 100C is 17.4 - with 50 weight ranging from 17 to 21 cSt). Just a bit of shearing and/or dilution and you’re in 40 weight territory with a lot of buffer before it could thin out too much.

If you can find Pennzoil Platinum in 5W-50, that would be a good choice, too (cSt 17.8 @ 100C) … but their 15W-50 is much thicker (cSt 21.4 @ 100C) and I would expect you’d notice the loss in power and fuel economy over the other choices if you went with a thick 50 weight oil.

For the record, I would use any 15w40 conventional HDEO or marine oil … as well as any 5W-40 synthetic of the same type.

Steve S, I don’t blame justinf89 for not wanting to go with an overpriced OEM oil … they are a rip-off and usually only deliver mediocre performance. It’s principle.

 

[justinf89]

Originally Posted By: Bror Jace
Again with these manufacturers and their not-quite-well-thought-out oil recommendations.

It seems they are OK with straight 30 weights ... but don't like 10w30 (and presumably 0W-30, 5w30, etc …) or even XW-40s. Presumably, they are concerned that these oils, even in “synthetic” form (whatever that means these days) will shear down. I think that’s a concern … but why skip over one of the most common marine oil weights: 15w40 and recommend an XW-50? That makes very little sense.

I agree with Steve S that any multi-viscosity oil is going to give you good cold-start performance in Virginia so no worries there. I would pay more attention to the viscosity at operating temp as well as the oil’s reputation for thinning (look at used oil analysis posted here).

Nothing wrong with Mobil 1 15W-50. If it’s plentiful and reasonably priced. It’s not even a thick 50 weight … typically close to a “45” weight (published viscosity @ 100C is 17.4 - with 50 weight ranging from 17 to 21 cSt). Just a bit of shearing and/or dilution and you’re in 40 weight territory with a lot of buffer before it could thin out too much.

If you can find Pennzoil Platinum in 5W-50, that would be a good choice, too (cSt 17.8 @ 100C) … but their 15W-50 is much thicker (cSt 21.4 @ 100C) and I would expect you’d notice the loss in power and fuel economy over the other choices if you went with a thick 50 weight oil.

For the record, I would use any 15w40 conventional HDEO or marine oil … as well as any 5W-40 synthetic of the same type.

Steve S, I don’t blame justinf89 for not wanting to go with an overpriced OEM oil … they are a rip-off and usually only deliver mediocre performance. It’s principle.


Great help, I appreciate the help. So it sounds like their looking for a viscosity between sae30 and 50, or 9.3-21.9 cst so I looked through many data sheets and it looks like Mobil 1 15w-50 is a good choice. Thanks everybody

 

[Bror Jace]

"So it sounds like they're looking for a viscosity between SAE 30 and 50, or 9.3-21.9 cSt."

Yes ... is that crazy or what? And their recommendations skipped over all the 40 weight oils which are smack-dab in the heart of their recommended range.

And people on this site (occasionally) wonder why I second guess the nonsensical recommendations of some manufacturers.

 

[lars11]

Now from Sweden where volvo penta headquarters: The 30 synthetic is only in the US! In sweden there are only 20w50 available OEM, one synthetic and one mineral. Volvo offers a 15w40 mineral too, for the turbo compressor diesels.

No 30 synthetic at all, can't even be ordered. So don't get hung up on that oil. Rumor has it that is made by Amsoil for the 4.3 V6 that was picky on oil in the newer versions with higher output.

The synthetic 20w50 is recommended from 2005 when Volvo introduced the Gxi, which is a multipoint injected HO engine, and also extending OCI to 100 hrs I think.
My 1999 5.0Gi has the mineral recommendation and 50 hr OCI. I run Delvac MX 15w40 in mine with excellent results so far.

The volvo recommendations are schizofrenic, sure, but all knowledge signals to keep away from low viscosity, high VI oil that are sensitive to any kind of thinning.

Remember that not all Volvos have oil coolers. The mercs have that and, voila, they recommend 25w40. Signalling same thinning but lower temp peaks.

 

[Bror Jace]

"but all knowledge signals to keep away from low viscosity, high VI oil that are sensitive to any kind of thinning."

Yes, good advice in just about any demanding application.

One clarification from something above: 30 to 50 weight SAE Crankcase is not 9.3 21.9 cSt. It's more like 9.0 to 18.5.
21.9 cSt appears to be the ceiling of the SAE Crankcase 60 range.

Take a look at this chart:

http://i229.photobucket.com/albums/ee149/BrorJace/Miscellaneous/viscositychart3.gif

(zoom in or download for best resolution)

 

[BigCahuna]

I read the your manuals recommendations for oil, and the only oil that evens mentions synthetic oil is their 30 wt. The other call for a CE/SG rated oil of 15/50,20/50 or below 0 Degrees 20/20, or 10 wt. Most 20/50 wt motorcycle oils have the SG rating, not sure about Mobil 1 15w50 wt.I doubt your going to be using the boat below 32 df, if it was mine I'd go with either the 15/50 or the 20/50.,