After looking over the recent Mobil 1 0w-40 thread and reading that it is known to shear in the 30wt range I thought about Xw-20 oils and how I do not recall seeing any in the used oil analysis section that had sheared past 20wt. I also frequently read on here that 5w30 tends to shear to a 20wt often times. So my question is are 20wt oils (such as 0w and 5w-20) more shear stable than the other multi-viscosity grades?
20wt oil shear stability?
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This is from what I have read, and only speculation, but I think it's because a 0w20 or 5w20 has less additives making it a multi-viscosity oil. The further the 5w is from the other number, say a 50 the more chance it has to shear is how I understand it.
20 is a lot closer to 5 than 30 is to 5 or 0 is to 40 etc...
Someone correct me if I'm wrong.
20 is a lot closer to 5 than 30 is to 5 or 0 is to 40 etc...
Someone correct me if I'm wrong.
StevieC is correct; furthermore most synthetic, particularily GP IV & V 0W-20 and 5W-20 oils have little or no VI added to their formulations at all. The same also applies to the 10w30 grade.
Originally Posted By: StevieC
This is from what I have read, and only speculation, but I think it's because a 0w20 or 5w20 has less additives making it a multi-viscosity oil. The further the 5w is from the other number, say a 50 the more chance it has to shear is how I understand it.
20 is a lot closer to 5 than 30 is to 5 or 0 is to 40 etc...
Someone correct me if I'm wrong.
What? Amsoil doesn't have a page on their website talking about this?
This is from what I have read, and only speculation, but I think it's because a 0w20 or 5w20 has less additives making it a multi-viscosity oil. The further the 5w is from the other number, say a 50 the more chance it has to shear is how I understand it.
20 is a lot closer to 5 than 30 is to 5 or 0 is to 40 etc...
Someone correct me if I'm wrong.
What? Amsoil doesn't have a page on their website talking about this?
Originally Posted By: postjeeprcr
Originally Posted By: StevieC
This is from what I have read, and only speculation, but I think it's because a 0w20 or 5w20 has less additives making it a multi-viscosity oil. The further the 5w is from the other number, say a 50 the more chance it has to shear is how I understand it.
20 is a lot closer to 5 than 30 is to 5 or 0 is to 40 etc...
Someone correct me if I'm wrong.
What? Amsoil doesn't have a page on their website talking about this?
I can take a joke, and that was a good one!
Originally Posted By: StevieC
This is from what I have read, and only speculation, but I think it's because a 0w20 or 5w20 has less additives making it a multi-viscosity oil. The further the 5w is from the other number, say a 50 the more chance it has to shear is how I understand it.
20 is a lot closer to 5 than 30 is to 5 or 0 is to 40 etc...
Someone correct me if I'm wrong.
What? Amsoil doesn't have a page on their website talking about this?
5w20 base oil is 3.9 cst and 5w30 base oil is 4.1 cst. at 100degC .To get to the working viscosity you nedd to add more vii's to the 30 wt.,and these can/do shear down. The base oil can shear also, but it's much more resistant to it.20w50 base oil is a 10+ cst., so a 30 wt. even without any vii's, that probably why it gets the results it does.
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