THIS ^^^
If all oil is too thick when cold...
- Thread starter SnowDrifter
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I would be quite interesting using a 10W-40 rather than 0/5-40 but I've seen on this site that there is a quality issue with that viscosity.
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The main fret with that viscosity comes from when most oils were primarily dinos and the base stock were much lower quality than they are today which would cause heavy shearing. If you used a high quality synthetic oil like Mobil 1 high mileage 10w-40 I'm sure that it will perform to your expectations.
The base stock indirectly contributed to the necessity of a large amount of VII which was of poorer quality back then. Base stock molecules do not shear but VII can.
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this^^
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A 0w30 should be the standard w/o any need for a 5w or 10w. Why? Because all engine oil will be roughly near 200F at operating temp, and maybe a tad above when ambient is really hot like 110-120F.
Short of having an electric oil pump that you can turn on before ignition, thinner oils will move faster, which is a benefit at start time. There's also less parasitic drag with a thinner oil, thus getting things started a bit faster too.
But, 0w30 has way more stuff in it that breaks down with use, vs say the 10w30. A 0w30 becomes less chameleon with use vs the 10w30. How much so depends on actual application. High compression engines do more damage to oil than std or low compression engines. Engines that drive with relatively low load will have oil that lasts longer vs engines that drive with heavy loads all the time. Then factor in power of the engine.
Short of having an electric oil pump that you can turn on before ignition, thinner oils will move faster, which is a benefit at start time. There's also less parasitic drag with a thinner oil, thus getting things started a bit faster too.
But, 0w30 has way more stuff in it that breaks down with use, vs say the 10w30. A 0w30 becomes less chameleon with use vs the 10w30. How much so depends on actual application. High compression engines do more damage to oil than std or low compression engines. Engines that drive with relatively low load will have oil that lasts longer vs engines that drive with heavy loads all the time. Then factor in power of the engine.
OVERKILL
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The number of (incorrect) assertions, speculation and generalizations made here is truly incredible.
1. As long as the oil isn't past the pumping point, it will start pumping immediately. That's one of the main purposes of the Winter rating.
2. Oil pumps are positive displacement, so unless the pump is on the relief, it is displacing the same amount of oil whether it's 0w-16 or 15w-40
3. A 0w-30 does not have "way more" stuff in it, which by "stuff" I assume you mean VII. It may have a higher percentage than a synthetic 10w-30, but then it may not. It will depend on the base oil blend of the product. 10w-30's are usually blended with cheaper bases because they don't need to meet the cold temperature requirements that a 5w-30 or 0w-30 has to. Those bases may actually be thinner, depending on the base oil selected, like Group II for example.
4. No, high compression engines do not do more damage to oil. Honda's S2000 engine had no exotic oil specs nor have myriad other engines with high compression ratios, including Mazda's Skyactiv engines. Engines with a million feet of timing chains have a higher propensity to shear VII polymers.
5. There are myriad factors that determine how long a given oil can be run including sump size, fuel dilution, oil temperature, short tripping or non....etc. Semi's run very long
OCI's despite being under heavy load for a significant duration of their operating cycle because they have excellent filtration and massive sumps. A car that's short-tripped under very light load can destroy the oil in a much shorter period of time than the same car with higher average load that's operated for long commutes every day.
4WD
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OVERKILL
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I have,
The quality of a base oil in an engine oil can not overcome poor service conditions and reserve (sump size).
Base oil quality(defined as higher VI and less aromatic hydrocarbons content) is more of a display of academic asthetics than a function of capability In the internal combustion engine.
I believe the quality issues of 10w40 were more during the era where all oils were solvent refined dino drippings, in order to get the operating viscosity of SAE40 they took a fairly thin base oil that could meet 10W pumpability requirements and loaded it with tons of VIIs which as the base oil evaporated or oxidized caused the VII to form a plasticy sludge.
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There's absolutely nothing wrong with 10W40 oils. 10W40 was actually an oem spec for my 300ZX.
Another factor is engine revs. An engine that's doesn't put out a ton of HP but revs to the moon will shear down the oil faster in the same miles driven as a vehicle that is making higher HP but at much lower revs. All others factors held constant besides revs and load, the higher revving engine will shear oil faster even if the load is less.
Completely agree. To people saying 15w40 or thicker are ok at freezing and below, you can see that the difference between 5w30 and 15w40 is big even at 0°C. Not saying it is a necessarily a problem and that thick oil can't be pumped however.
You know this Shannow, but for the layperson, As I often mention to zeeOsix, these positive displacement pumps are all but a thing of the past in passenger cars, as engineers/designers look to improve parasitic losses in engines. Even a decades ago, excess pressure /volume of pumped fluid is bypassed around the pump in many engines.
Its Like pushing a stick of Liquorice with a 12 " machinist rule.
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exactly, grew up in Fargo ND in the 60's and 70's and started plenty of big block V8 engines with 10W40 oil in the sump . My dad and grandpa would often use block heaters and battery warmers on nights when it would dip below about -15F. ND had a few days days of -20F and maybe a dozen days of 0 to -10 most years and maybe a day or 2 of -30F every January.
OVERKILL
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I was actually pointing out the additives percentage, which is 20% and includes VII load, versus 18% for the 0w-30 displayed in 4WD's chart.
The oil pumps in newer cars are still positive displacement - they are variable displacement, that's the only change from the old fashioned PD pump. So not sure what your point is - you might want to elaborate.
The PD pump going into pressure relief has no factor on if it can pump cold thick oil or not. Even variable displacement PD oil pumps have a pressure relief valve, and it's still going to pop open if the output pressure exceeds the valve setting due to the oil being thick.
Agreed the positive displacement (gerotor or lobe or gear) is at the pump proper, and the pump must lube itself, but that isnt it's purpose. It is to lube plain bearings and component proximal and distal in the engine proper through discharge, but will be limited in ability to move lubricant volume by the viscosity of the fluid when bypass is initiated. Volume flow though a restricted orifice at constant pressure will be lessend with increasing viscosity.
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