10W vs 10W-30 vs SAE 30 cylinder wear

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I LOVE to see this straight weight talk going on and ill give a few points of my own on the issue.

maybe this is why small engine manf like briggs and stratton want you to use sae 30 for all temps down to freezing. maybe they realised long ago that a straight weight with no VII IS better then a VII enhanced oil at protecting engines under certain conditions, espically ones like lawnmowers with no oil pumps, minimal lubrication, and high sustained rpm's. (if you can call 3600 rpm's high that is).

my generac ultra source 15Kw 22.5 surge genset specs sae 30 year round for everything but freezing temps. this is pretty typical of most smaller engines today. this genset starts up and goes right to 3600 rpm's for 10 seconds. then if there is no load on the generator head, it idles down to 1500 rpm's and will stay there untill a load is applied (electronic computer controlled govenors rock!). the manual also states that a 10w30 synthetic is ok for all the tempatures an sae 30 can be run, with the additional benefit that it can be run below freezing.
the manual says nothing about conventional 10w30. i know this isnt a car engine guys but it does have full flow pressurized lubrication just like a car, and its got a oil filter and external oil cooler to boot so the motor is atleast similar to a car. the wording of the manual seems to imply that they dont want any vii's in the oil without actually saying that. why else make that recomendation?
ive been running 15w40 diesel oil in it because i already have the oil.
but i wonder how much VII is in diesel oil? its a shame that oil manf dont list the ammount of VII present in their oils. id be willing to bet theres less VII in a 15w40 then there is in a 10w30 or a 5w20.
i read somwhere a long time ago that it takes less VII when you start out with a heavyer oil. for instance, less VII to make a 20w40 than a 10w30. ive got no proof of this but i was hoping some of you oil experts could chime in. bruce381 or anyone else, care to take a stab?
 
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When discussing the "cold" performance on the original graph on page 1, we need to keep in mind that the temperature scale is in celcius. Therefore the "cold" data in the graph is essentially room temperature.

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True. But I wonder just how long after start up the cyl wall temps get up to "room temp"? A few seconds at most?

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Good point G-man, when I start my 2-cycle engines (50cc) they tend to get warm pretty fast at idle and roughly 30 seconds in they get so hot I am unable to hold my thumb on the cooling fins. Granted an engine piston may have more mass, but my 500cc air cooled bike took a little longer to warm up due to the massive engine. Grant it this was the heat that I felt outside, so we have to count in the heat transfer delay.

Do you think that the cooler oil in the sump would have any affect in cooling the warmed up pistons?

Waiting for Terry to chip in, if anyone, Terry would have lots of evidence to back this up.
 
Buster - I really don't knew what to think about M1 0W-40. Lots of people seem to like it, especially in the euro car group. Yet it shears down substantially and the UOA's from it don't look all that good IMO. I have it in one car right now though, one that didn't do so well on GC and I'm interested in seeing that result. One thing we've also talked about in the past is sludge formation from sheared VII polymers. Yet that oil is considered an extended drain oil.

Jag - Some of these things we sort of take for granted here and on one hand these tests *sort of* confirm it. For instance, that VII's are "bad" if for no other reason than they take the place of other possibly more useful things in a given formulation. Like additional anti wear components, or for that matter just more of the oil itself. And also because of the sludging issues as mentioned. Yet the multi weight dino oils need them them as must a lot of the synthetics to have VI's up around 150 or more. And even with the VII's the UOA's they give are often good or even great.

That's as confusing to me as the low temp wear numbers we saw in that test graph. I obviously can't explain it, that why I ask these questions.
wink.gif
And it's even more confusing to me when I notice some of our members in the heavy equipment and trucking industries talk about the wear reductions they saw back in the day when they moved from straight weight oils to multi-weights...

Overall, good thread and useful informantion but much to ponder!
 
jsharp, I agree 100%. I think he made a few good points.

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For instance, that VII's are "bad" if for no other reason than they take the place of other possibly more useful things in a given formulation. Like additional anti wear components, or for that matter just more of the oil itself. And also because of the sludging issues as mentioned. Yet the multi weight dino oils need them them as must a lot of the synthetics to have VI's up around 150 or more. And even with the VII's the UOA's they give are often good or even great.

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It's obviously better to rely on the base oil than VII's. I'd assume that most pao/ester synthetics contain little VII's. M1 0w-40 or any oil with a large spread should contain more. Then you have the issue of quality among VII's which vary.
 
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But do even high quality VII provide the same protection as oil? That is the question.


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The problem is you can always isolate one component and draw some conclusion but you really have to look at the whole formulation. I don't know the answer to your question but if it were that simple, we should all be using straight weight engine oils.

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"Most oil manufacturers use a quick shearing viscosity index improver that helps their oil pass the test by allowing its viscosity to drop," said the lab rep. "When the viscosity drops, intrafluid friction drops and fuel economy rises. But wear protection also drops. Of course, wear protection isn't a concern in the Sequence VI test. Fuel economy is the only concern.


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Steve thanks.

I just called Dave and RL 5w-20, 5w-30 and 10w-30 all do NOT use any VII's. Fyi.

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I got it from this site some time ago, that the only Redline with VII is the 5w40. Great stuff. Am running Redline 10w30 in my Generac generator V-twin engine.
 
Seriously though, regarding VII's, if the spread of viscosities isn't too great, would just a little of high quality VII be OK, if not beneficial, or is jsharp along the right track by stating that keeping the most room for a very high quality base oil, followed by a decent additive package, be the best wear protection.

I don't exactly live in the arctic, but I do not live in 50+F temperatures all year either, so that is why I could appreciate the little bit of "comfort" level with a multigrade flowability. Or is my thinking off and sacrificing quality by desiring an oil that has to contain some VII to make the range?
 
From memory using a OCP liquid VII
10/40 about 10%-12%
5/30 about 7%-10%
15/40 about 5%-7%
10/30 about 5%-7%
20/50 about 5%

depends on base stock
bruce
 
I'm thinking we should all drain out our VII riddled oil and switch to straight grade.

Straight Grade: The Anti-Girly Man's Oil.
grin.gif
 
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I'm thinking we should all drain out our VII riddled oil and switch to straight grade.

Straight Grade: The Anti-Girly Man's Oil.
grin.gif


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Uh oh, now what do I do with my 220 quarts of stash? Only 5 quarts are straight grade.
confused.gif
 
TallPaul...tell your generator that it really needs to drink more, than replenish with the awesome straight grade Valvoline brew of your choice...
 
Please let me not be the only one that feels as though his/her head is spinning!
ooo.gif


What I find strange is that in looking at some of the specs for a straight 30 wt oils, I find a HTHS of say 3.8, where as a multi-wt of say 5/10w-30 is around 3.2. In theory, the viscosity of the straight 30wt would be less as temperatures advance beyond 100c (lower VI), but yet the HTHS #'s are higher for the straight 30wt than for the multi-wt's. I understand that the VII's are likely the cause of this, but for some reason this seems in excess. Perhaps I'm tricked by a typo, or my brain just can't grapple this at the moment - for so long I have stayed away from straight wt's thinking them inferior (perhaps I have been dazzled by all the marketing and so forth for the latest and greatest in lubricant formulations!!!). Then again I haven't had any first-hand "wisdom" passed along to me concerning straight wt's.
confused.gif


Well, I've fought the urge to go purchase some straight wt oils to experiment with...for now. I'm holding the actual data yielded from UOA's to settle my nerves on these matters with current lubricant formulations in more recent engines in real world use. There still however exists a voice of sorts in the furthest reaches of my mind telling me that I'm provided my valued equipment with inferior protection. For some it's like having an angle on one shoulder and the devil on the other. So as for just how long I'll keep from finding some straight weights on my oil shelf will be in question.
laugh.gif


Take care...and rest easy!
thumbsup.gif
 
Quote:

From memory using a OCP liquid VII
10/40 about 10%-12%
5/30 about 7%-10%
15/40 about 5%-7%
10/30 about 5%-7%
20/50 about 5%

depends on base stock
bruce

Click to expand...

Any thoughts on how these might change with a good Grp III or IV base? Or are those included in the above?
 
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