Originally Posted By: Shannow
Originally Posted By: CATERHAM
The same individuals that would lambaste a high VI 40 grade like Mobil 1 0W-40 shearing to a 30 grade are getting their kickers in a twist postulating about a 20 grade oil shearing to a 16 grade as a if shear really matters in an OEM oil.
There are some very shear stable 0W/5W-20 oils and some that are not but as a grade 20 grade oils are more shear stable than 30 grade oils which are more shear stable than 40 grade oils etc. Probably the most shear prone oil is the 5W-50 grade.
Mobil 1 0W-40, and other 5W-50s have EXACTLY WHAT ??? to do with 0W-16, and the assertion that 16 works as some 20s fall below the HTHS minimum...you probably ought to create another thread if you want to talk about these oils shearing...
I wonder if we'll be hearing that a 20 grade oil shears to a 16 grade after a few thousand miles, so using a 16 grade oil is perfectly safe because a 16 grade oil shears less than a 20 grade. IIRC we heard similar stories about 30 grade oils, shearing to a 20 grade oil, and 20 grade oils didn't shear, or sheared very little and stayed in grade. I'm not sure I'll buy into it though with regard to 16 grade oils. I believe the engine will be specifically designed for 16 grade oils, and no way will I put a 16 grade oil in a vehicle calling for a 20 grade oil. Especially when prior models with the identical engine [bearings, cam lifters, oil pump, etc.] used 5W30. They simply slapped a use 5W20 oil fill cap on and called it a day. I'm sure a 16 grade oil will be just fine in an engine specifically designed for it, with the modified, upgraded or redesigned parts.
Originally Posted By: CATERHAM
The same individuals that would lambaste a high VI 40 grade like Mobil 1 0W-40 shearing to a 30 grade are getting their kickers in a twist postulating about a 20 grade oil shearing to a 16 grade as a if shear really matters in an OEM oil.
There are some very shear stable 0W/5W-20 oils and some that are not but as a grade 20 grade oils are more shear stable than 30 grade oils which are more shear stable than 40 grade oils etc. Probably the most shear prone oil is the 5W-50 grade.
Mobil 1 0W-40, and other 5W-50s have EXACTLY WHAT ??? to do with 0W-16, and the assertion that 16 works as some 20s fall below the HTHS minimum...you probably ought to create another thread if you want to talk about these oils shearing...
I wonder if we'll be hearing that a 20 grade oil shears to a 16 grade after a few thousand miles, so using a 16 grade oil is perfectly safe because a 16 grade oil shears less than a 20 grade. IIRC we heard similar stories about 30 grade oils, shearing to a 20 grade oil, and 20 grade oils didn't shear, or sheared very little and stayed in grade. I'm not sure I'll buy into it though with regard to 16 grade oils. I believe the engine will be specifically designed for 16 grade oils, and no way will I put a 16 grade oil in a vehicle calling for a 20 grade oil. Especially when prior models with the identical engine [bearings, cam lifters, oil pump, etc.] used 5W30. They simply slapped a use 5W20 oil fill cap on and called it a day. I'm sure a 16 grade oil will be just fine in an engine specifically designed for it, with the modified, upgraded or redesigned parts.
