OP is looking for fuel economy so Red Line is still the best option. Unlike engine oil, low temp visc is pretty much irrelevant in gear oil. Average temp in Portland is 36-80F annually.
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lightest/thinest 75w-90 gear oil
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Originally Posted By: azsynthetic
Average temp in Portland is 36-80F annually.
So it's 50/50 then? When the oil is cold (below 68F) the Motul is more efficient and above 68F the Red Line has a slight advantage.
Average temp in Portland is 36-80F annually.
So it's 50/50 then? When the oil is cold (below 68F) the Motul is more efficient and above 68F the Red Line has a slight advantage.
Originally Posted By: martinq
Originally Posted By: mechtech2
Going from the lightest to heaviest gear oil in any range will not net you measurable results.
I'm not looking for measurable results. I'm looking for a GL-5 SAE90 that would out-perform or out-flow the Motul Gear 300 75w90. Something that fit into a 70w90 classification should do it.
The OP is 'thereed'. He stated specifically that he was looking for a gas mileage increase.
I am not sure why you superceded him.
Originally Posted By: mechtech2
Going from the lightest to heaviest gear oil in any range will not net you measurable results.
I'm not looking for measurable results. I'm looking for a GL-5 SAE90 that would out-perform or out-flow the Motul Gear 300 75w90. Something that fit into a 70w90 classification should do it.
The OP is 'thereed'. He stated specifically that he was looking for a gas mileage increase.
I am not sure why you superceded him.
Originally Posted By: martinq
So it's 50/50 then? When the oil is cold (below 68F) the Motul is more efficient and above 68F the Red Line has a slight advantage.
Not really, once the car is moving gear fluid temperature will increase rapidly to above 68F. So, 95% of the time it will be above 68F.
So it's 50/50 then? When the oil is cold (below 68F) the Motul is more efficient and above 68F the Red Line has a slight advantage.
Not really, once the car is moving gear fluid temperature will increase rapidly to above 68F. So, 95% of the time it will be above 68F.
So, IS or IS NOT a very high VI important in a gear oil used in a rear axle/diff, or is it ALL based on conditions/ambient temps it is being used in??
Originally Posted By: dailydriver
So, IS or IS NOT a very high VI important in a gear oil used in a rear axle/diff, or is it ALL based on conditions/ambient temps it is being used in??
A high(est) VI is always beneficial as long as the other requirements are met and the fluid is stable (does not shear-down). This goes for almost all lubricating / hydraulic fluids in all applications.
So, IS or IS NOT a very high VI important in a gear oil used in a rear axle/diff, or is it ALL based on conditions/ambient temps it is being used in??
A high(est) VI is always beneficial as long as the other requirements are met and the fluid is stable (does not shear-down). This goes for almost all lubricating / hydraulic fluids in all applications.
If you want thinner, why not try 75w85? I think Toyota and Redline have them.
I was really hoping for a 70w90 and I think I found it with the Motul Gear 300. I'm sure there's something similar out there.
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