So my question is this I know the W on the label is for winter like 5W30. I understand the 5 is a viscosity that behaves well in cold weather and when the oil gets hot the viscosity is at a 30 grade. So where does the term weight come from when it all has to do with viscosity?
Why do people say weight when it’s viscosity?
- Thread starter Fishstyx
- Start date
You have to add a few things to your assessment.
Such as the 5W would be the viscosity of an sae 5 AT THAT TEMPERATURE. Same with the 30 part, but at a much higher temp.
Such as the 5W would be the viscosity of an sae 5 AT THAT TEMPERATURE. Same with the 30 part, but at a much higher temp.
The general public isn't as intelligent as BITOG members are. The term, viscosity, is mysterious while weight is simple to comprehend.
OVERKILL
$100 Site Donor 2021
That's incorrect.
The number preceding the W is the Winter Grade. It's a grade, just like the number that comes after the W.
The grade in front of the W is derived through CCS and MRV testing and has absolutely no relation to the number after the W, which is based on the KV100 viscosity.
Furthermore, this are no SAE 5 or 0 grades, which should be a big clue as to the flaw in that thought process.
This probably the best answer I will get
OVERKILL
$100 Site Donor 2021
Well, don't feel bad, Valvoline for example, uses Weight and Grade interchangably in articles like this one:
Understanding Oil Weights: What Oil Weight Means and What Oil Weight to Use - Valvoline™ Global Europe - EN (valvolineglobal.com)
Understanding Oil Weights: What Oil Weight Means and What Oil Weight to Use - Valvoline™ Global Europe - EN (valvolineglobal.com)
Probably the same reason why individuals believe a $30 spectrographic analysis or typical values from a PDS are a technical indicator for future performance of an oil.
This is like a gas vs petrol question. It may not be scientifically correct but people still use them interchangeably
For practical purposes "weight" and "grade" are used interchangeably.
The only thing I can think of why weight is referenced is from the oil industry when they are drilling and calling out the weight of the drilling of the mud and it’s correlating viscosity and that terminology has carried over. So if I was to call out the weight of a mud it could be 10 pounds at a 37 viscosity and that’s where the term weight comes from.
Hermann
Site Donor 2023
It's like the old question, Do you take of pee, or leave a pee.
Honestly, I don't want it back.
Honestly, I don't want it back.
The terms weight, viscosity and grade are used in oil company ad copy and documentation pretty much interchangeably. I don't think there is much point in splitting hairs about the subject.
MolaKule
Staff member
Weight really makes no sense unless you are for some reason referencing density in an equation, but a "grade" refers to a viscosity and a designation such as 5W20 refers to a viscosity "range" between cold and hot temperatures.
Viscosity is measured in either Absolute viscosity units or Kinematic viscosity units.
Viscosity is measured in either Absolute viscosity units or Kinematic viscosity units.
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I think it would be far fetched that it comes from “mud weight” but you never know. It seems in many industries “weight” is used where viscosity would be a better term.
I always thought:
- Viscosity describes Grade
- Grade describes Viscosity
- Weight = how much mortadella I want to buy at the deli counter.
Why do some older people say "hi test" when they want premium gas.
Why do some people say "DEF fluid" when stands for diesel exhaust fluid. They are saying diesel exhaust fluid fluid.
Why do some people say "DEF fluid" when stands for diesel exhaust fluid. They are saying diesel exhaust fluid fluid.
I demur, might be a bit of hubris. Some of the places where I do my intellectual grazing sometimes leave me feeling like a dotard. Just look above the internet swamp miasma and our equals can be found.
As I get older I find myself working on that often.(Ie not correcting.. even if its someone telling me to inflate my tires to the sidewall psi...
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