0w5 motor oil

[CATERHAM]

From what I remember NEO 0W-5 is a light 0W-20 oil with a 180 VI. The 0W-5 label is a marketing gimmick. Not surprisingly, NEO provides virtually no viscosity spec's for this oil:

http://www.bakerprecision.com/neo/0w5.htm

 

[dparm]

Originally Posted By: circuitsmith
I wonder if lower cold viscosities are on the way, eg. 00W-20 or 00W-10.



The percentage of vehicles used in climates where the temperatures are that cold is so small that I can't see this happening.

 

[JAG]

Oil pressure is not what separates journal bearings. Pressure differences in the oil in the gap from the rotation of the journal are what separates them. Another thing to keep in mind are that oil pumps NOT in bypass tend to flow less volume as the viscocity drops because of internal leakage, so oil pumps must be designed appropriately for the expected viscosity ranges they will pump.

 

[ARB1977]

As long as the manufacturer mets the spec... Ill use it.

 

[CATERHAM]

Originally Posted By: JAG
Another thing to keep in mind are that oil pumps NOT in bypass tend to flow less volume as the viscocity drops because of internal leakage

From a practical viewpoint that scenerio would not happen unless the oil's viscosity was sufficiently low enough to allow the oil back pressure to drop well below that specified for the engine.

Put another way, the oil engine light would be on and one would be well advised to take some remedial action.

 

[cmlind]

At present there are no official SAE 15, 10 or 5 grades, but the industry is working on defining these new grades.

SAE 10 straight grade has been used for years as a winter grade, mainly for diesels before multi grades were available. I have seen it used in winter in air cooled Deutz engines recently.

 

[JAG]

Originally Posted By: CATERHAM
Originally Posted By: JAG
Another thing to keep in mind are that oil pumps NOT in bypass tend to flow less volume as the viscocity drops because of internal leakage

From a practical viewpoint that scenerio would not happen unless the oil's viscosity was sufficiently low enough to allow the oil back pressure to drop well below that specified for the engine.

Put another way, the oil engine light would be on and one would be well advised to take some remedial action.

That's only true if internal leakage only starts happening when oil reaches a certain low enough viscosity concurrently with or after the oil pressure reaches the value at which the oil pressure light comes on. Internal leakage gradually increases as viscosity decreases, assuming bypass is not happening. The resulting oil pressure could be above the minimum threshold the whole time. But when leakage happens, flow volume decreases. I'm not raising an alarm; just pointing something out.

 

[CATERHAM]

I can't see that happening at normal oil pressure levels.

For example if the spec' minimum OP is 60 psi at elevated rev's with an oil pump by-pass set at 95 psi, you will have maximum oil flow through the engine with an oil viscosity that generates 60 psi and the oil flow will decrease with more viscose oil's that generate higher oil back pressure up to the by-pass point.

Running an oil that generates less than the minimum recommended oil back pressure will increase oil flow but if the viscosity continues to drop (due to increasing oil temp's for example) at some point bearing wiping will occur.

At what point bearing leakage limits oil flow is an interesting question but I'm sure it is well below the optimum recommended minimum OP for an engine. In which case it renders the question academic.

 

[spock1]

Originally Posted By: CATERHAM
From what I remember NEO 0W-5 is a light 0W-20 oil with a 180 VI. The 0W-5 label is a marketing gimmick. Not surprisingly, NEO provides virtually no viscosity spec's for this oil:

http://www.bakerprecision.com/neo/0w5.htm


Thanks for the added information.

 

[JAG]

Caterham, I was talking about internal oil pimp leakage, not bearing leakage.