Multi-viscosity engine oil.
- Thread starter BarkerMan
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do not know never worked with them but think the treat rate is same or close anyway. When using a soulbilzed liquid version they have about 10% or so polymer so a 10% treat is same as 1.0% of a solid.
bruce
bruce
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If VII's were good for lubrication would we not see some more conventional 0w-30 engine oils?
Originally Posted By: BarkerMan
If VII's were good for lubrication would we not see some more conventional 0w-30 engine oils?
I don't think anyone "in the business" would claim that VIIs are "good for lubrication" in any other sense than that they permit an otherwise "too thin" oil to mimic a "thicker" oil at higher temps.
If VII's were good for lubrication would we not see some more conventional 0w-30 engine oils?
I don't think anyone "in the business" would claim that VIIs are "good for lubrication" in any other sense than that they permit an otherwise "too thin" oil to mimic a "thicker" oil at higher temps.
Originally Posted By: BarkerMan
If VII's were good for lubrication would we not see some more conventional 0w-30 engine oils?
I don't think they would even meet the volatility requirements of API, etc. so they wouldn't even get a chance to possibly fail engine test stand tests.
If VII's were good for lubrication would we not see some more conventional 0w-30 engine oils?
I don't think they would even meet the volatility requirements of API, etc. so they wouldn't even get a chance to possibly fail engine test stand tests.
Note the following quotes from the article "Experimental study on the shear thinning effects of viscosity index improver added lubricant by in-situ optical viscometer" by Siyoul Jang* School of Mechanical & Automotive Engineering, Kookmin University 861-1, Jungnung-dong, Sungbuk-gu, Seoul 136-702, Korea (Received April 15, 2003; final revision received June 2, 2003)
Quote:
Many experimental and numerical studies about elastohydrodynamic lubrication (EHL) have been performed on
the assumption of Newtonian fluid. Most published formulas relating the properties such as viscosity, contact velocity, applied load, viscosity-pressure characteristics and elastic modulus in both experimental and numerical investigations predict film thicknesses with the assumption of Newtonian fluid by Hamrock (1994). However, recently developed lubricants show very non-linear behaviors of viscosity-shear rate especially in EHL regime, where high concentrated pressure (1.0 GPa), thin film thickness and large contact velocity (over 105 s-1) occur over the contact area. This is the reason that many VII’s additives for better performance of lubricant against temperature rise in EHL regime make the lubricant film unpredictively thinner at
high shear arte.
Quote:
In this work, optical interferometric measurement of EHL film thickness over the contact area is applied for the verification of load carrying performances of VII added lubricants, because it is possible only with fine resolution of length measurement of ~5 nm scale. Theoretically, higher rolling contact velocity under the same applied load makes the EHL film thickness thicker for Newtonian lubricant without any exemption. However, for shear thinning lubricant such as VII blended lubricant, higher contact velocity under the same applied load makes the EHL film thickness delicately thinner comparing to that of Newtonian lubricant. ... The load carrying capacities of some VII synthesized lubricant are tested and compared with Newtonian lubricant of base oil and it is found that the tested results agree well with theoretical tendencies.
Quote:
Many experimental and numerical studies about elastohydrodynamic lubrication (EHL) have been performed on
the assumption of Newtonian fluid. Most published formulas relating the properties such as viscosity, contact velocity, applied load, viscosity-pressure characteristics and elastic modulus in both experimental and numerical investigations predict film thicknesses with the assumption of Newtonian fluid by Hamrock (1994). However, recently developed lubricants show very non-linear behaviors of viscosity-shear rate especially in EHL regime, where high concentrated pressure (1.0 GPa), thin film thickness and large contact velocity (over 105 s-1) occur over the contact area. This is the reason that many VII’s additives for better performance of lubricant against temperature rise in EHL regime make the lubricant film unpredictively thinner at
high shear arte.
Quote:
In this work, optical interferometric measurement of EHL film thickness over the contact area is applied for the verification of load carrying performances of VII added lubricants, because it is possible only with fine resolution of length measurement of ~5 nm scale. Theoretically, higher rolling contact velocity under the same applied load makes the EHL film thickness thicker for Newtonian lubricant without any exemption. However, for shear thinning lubricant such as VII blended lubricant, higher contact velocity under the same applied load makes the EHL film thickness delicately thinner comparing to that of Newtonian lubricant. ... The load carrying capacities of some VII synthesized lubricant are tested and compared with Newtonian lubricant of base oil and it is found that the tested results agree well with theoretical tendencies.
Synthetic oil in general is promoted based on extended intervals by some oil producers and that most producers of synthetic oil claim less friction, better mileage or other description in that vein. Would it be fair to say that having no or very little in the way of VII’s is also very important? Would it not be true to say that no VII’s is the foundation of a better product and that such an oil would better resist all the forces that tend to defeat a lubrication system?
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