And why do we use it to describe oil viscosity? Does it come from some old unit of measure or procedure? Is it just a colloquialism? 10 weight, 20 weight, 90 weight? Why the term "weight"?
Where does the term "weight" come from?
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"The specific gravity of oil is defined as the ratio of the weight of a given volume of the product at 60°F to the weight of an equal volume of water at the same temperature. Water has a density of 8.33 Lbs/Gal at 60°F. So if an oil has a specific gravity of 0.85 then its density is 0.85 (8.33 lbs/gal) = 7.08 lbs/gal. This means if you have 2 gallons of oil then the weight is a little over 14 lbs. As you can see, water is the reference used for these measurements."
From the Mobile One website - don't ya just love Google?
From the Mobile One website - don't ya just love Google?
Does viscosity correspond to specific gravity? is 10 "weight" have a lower specific gravity than 20 "weight"?
Notice Mobil is specifically talking about the density and not viscosity.
Notice Mobil is specifically talking about the density and not viscosity.
A true search will reveal the "W" stands for winter.
Viscosity is measured by the amount of time a fluid takes to flow through an orifice....doesn't matter if it's referring to paint, engine oil, water, whatever....it's a measurement of time.
Viscosity is measured by the amount of time a fluid takes to flow through an orifice....doesn't matter if it's referring to paint, engine oil, water, whatever....it's a measurement of time.
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Think it goes back to the days of fractional distillation.
You had a range of fractions produced from the crude ranging from light to heavy.
You had a range of fractions produced from the crude ranging from light to heavy.
Originally Posted By: Burt
Next time when your wife asks if this outfit makes her look fat, say, no honey, just a little more viscous.
LOL! I needed that one today
Next time when your wife asks if this outfit makes her look fat, say, no honey, just a little more viscous.
LOL! I needed that one today
My question isn't regarding the "W" winter designation. It is specifically "why do people say "weight" when referencing the viscosity of oil?"
A reference to the the distillation process may be the answer but was there ever a direct correlation between engine oil specification and fractional distillation? i.e. did Packard/Ford/Studebaker/etc ever specify "xx weight oil"?
I get the feeling it's a colloquialism that won't die and the misunderstanding of the "W" winter designation perpetuates it.
A reference to the the distillation process may be the answer but was there ever a direct correlation between engine oil specification and fractional distillation? i.e. did Packard/Ford/Studebaker/etc ever specify "xx weight oil"?
I get the feeling it's a colloquialism that won't die and the misunderstanding of the "W" winter designation perpetuates it.
Originally Posted By: tom slick
A reference to the the distillation process may be the answer but was there ever a direct correlation between engine oil specification and fractional distillation? i.e. did Packard/Ford/Studebaker/etc ever specify "xx weight oil"?
Yup. Once upon a time there was a direct correlation between the viscosity of an oil and the length (or weight) of the H-C molecules it was made up from, back when GrI oil was all there was. Now it's not exactly so straight forward with VMs and synthetic/hydroprocessed oils changing that. Of course, the specification was not graded strictly by molecular weight and is thus indeed a colloquialism.
Crude oil is still technically referenced as light or heavy/extra heavy based on the 'weight' of HC molecules it's made up from. Needless to say, the light crude is of a lower viscosity than heavy.
A reference to the the distillation process may be the answer but was there ever a direct correlation between engine oil specification and fractional distillation? i.e. did Packard/Ford/Studebaker/etc ever specify "xx weight oil"?
Yup. Once upon a time there was a direct correlation between the viscosity of an oil and the length (or weight) of the H-C molecules it was made up from, back when GrI oil was all there was. Now it's not exactly so straight forward with VMs and synthetic/hydroprocessed oils changing that. Of course, the specification was not graded strictly by molecular weight and is thus indeed a colloquialism.
Crude oil is still technically referenced as light or heavy/extra heavy based on the 'weight' of HC molecules it's made up from. Needless to say, the light crude is of a lower viscosity than heavy.
Originally Posted By: Burt
Next time when your wife asks if this outfit makes her look fat, say, no honey, just a little more viscous.
Whatever you do, don't say "I've seen FATTER".
Next time when your wife asks if this outfit makes her look fat, say, no honey, just a little more viscous.
Whatever you do, don't say "I've seen FATTER".
It's just one of those things that happens in oil folklore. Just like people thinking that the "w" stands for winter when apparently it only denotes a multi-viscosity oil amd doesn't stand for anything (based on what I've read here). Or like people thinking that there was a judge's ruling based on a lawsuit that Mobil brought against Castrol.
-Dennis
-Dennis
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Hi,
tom slick - Yes the misunderstanding of "w" has led to this situation. It is perhaps over to all of us on BITOG to diminish its use
I does annoy me too
tom slick - Yes the misunderstanding of "w" has led to this situation. It is perhaps over to all of us on BITOG to diminish its use
I does annoy me too
Originally Posted By: bluesubie
It's just one of those things that happens in oil folklore. Just like people thinking that the "w" stands for winter when apparently it only denotes a multi-viscosity oil amd doesn't stand for anything (based on what I've read here). Or like people thinking that there was a judge's ruling based on a lawsuit that Mobil brought against Castrol.
-Dennis
"W" does stand for "Winter" according to API and SAE. Although I've never seen it, there could be a SAE 10-30 that would would be a "heavier weight"
when cold than a 10w30.
It's just one of those things that happens in oil folklore. Just like people thinking that the "w" stands for winter when apparently it only denotes a multi-viscosity oil amd doesn't stand for anything (based on what I've read here). Or like people thinking that there was a judge's ruling based on a lawsuit that Mobil brought against Castrol.
-Dennis
"W" does stand for "Winter" according to API and SAE. Although I've never seen it, there could be a SAE 10-30 that would would be a "heavier weight"
Originally Posted By: tom slick
Originally Posted By: bluesubie
It's just one of those things that happens in oil folklore. Just like people thinking that the "w" stands for winter when apparently it only denotes a multi-viscosity oil amd doesn't stand for anything (based on what I've read here). Or like people thinking that there was a judge's ruling based on a lawsuit that Mobil brought against Castrol.
-Dennis
"W" does stand for "Winter" according to API and SAE. Although I've never seen it, there could be a SAE 10-30 that would would be a "heavier weight"
when cold than a 10w30.
I would be very interested in reading more if you can provide a link on the API or SAE's web site.
-Dennis
Originally Posted By: bluesubie
It's just one of those things that happens in oil folklore. Just like people thinking that the "w" stands for winter when apparently it only denotes a multi-viscosity oil amd doesn't stand for anything (based on what I've read here). Or like people thinking that there was a judge's ruling based on a lawsuit that Mobil brought against Castrol.
-Dennis
"W" does stand for "Winter" according to API and SAE. Although I've never seen it, there could be a SAE 10-30 that would would be a "heavier weight"
I would be very interested in reading more if you can provide a link on the API or SAE's web site.
-Dennis
Last edited:
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Originally Posted By: bluesubie
Originally Posted By: tom slick
Originally Posted By: bluesubie
It's just one of those things that happens in oil folklore. Just like people thinking that the "w" stands for winter when apparently it only denotes a multi-viscosity oil amd doesn't stand for anything (based on what I've read here). Or like people thinking that there was a judge's ruling based on a lawsuit that Mobil brought against Castrol.
-Dennis
"W" does stand for "Winter" according to API and SAE. Although I've never seen it, there could be a SAE 10-30 that would would be a "heavier weight"
when cold than a 10w30.
I would be very interested in reading more if you can provide a link on the API or SAE's web site.
-Dennis
http://papers.sae.org/340098/
Quote:
It was recognized by 1930 that a classification for winter oils must be based on the viscosity of the oil at the starting temperature, and work was started on this problem. In June, 1933, the 10-W and 20-W oils, which are classified in accord with their viscosity at 0 deg. fahr., were adopted for publication and trial.
Originally Posted By: tom slick
Originally Posted By: bluesubie
It's just one of those things that happens in oil folklore. Just like people thinking that the "w" stands for winter when apparently it only denotes a multi-viscosity oil amd doesn't stand for anything (based on what I've read here). Or like people thinking that there was a judge's ruling based on a lawsuit that Mobil brought against Castrol.
-Dennis
"W" does stand for "Winter" according to API and SAE. Although I've never seen it, there could be a SAE 10-30 that would would be a "heavier weight"
I would be very interested in reading more if you can provide a link on the API or SAE's web site.
-Dennis
http://papers.sae.org/340098/
Quote:
It was recognized by 1930 that a classification for winter oils must be based on the viscosity of the oil at the starting temperature, and work was started on this problem. In June, 1933, the 10-W and 20-W oils, which are classified in accord with their viscosity at 0 deg. fahr., were adopted for publication and trial.
Originally Posted By: bluesubie
Originally Posted By: tom slick
Originally Posted By: bluesubie
It's just one of those things that happens in oil folklore. Just like people thinking that the "w" stands for winter when apparently it only denotes a multi-viscosity oil amd doesn't stand for anything (based on what I've read here). Or like people thinking that there was a judge's ruling based on a lawsuit that Mobil brought against Castrol.
-Dennis
"W" does stand for "Winter" according to API and SAE. Although I've never seen it, there could be a SAE 10-30 that would would be a "heavier weight"
when cold than a 10w30.
I would be very interested in reading more if you can provide a link on the API or SAE's web site.
-Dennis
You can do your own homework:
SAE W designation
API Winter Designation
Originally Posted By: tom slick
Originally Posted By: bluesubie
It's just one of those things that happens in oil folklore. Just like people thinking that the "w" stands for winter when apparently it only denotes a multi-viscosity oil amd doesn't stand for anything (based on what I've read here). Or like people thinking that there was a judge's ruling based on a lawsuit that Mobil brought against Castrol.
-Dennis
"W" does stand for "Winter" according to API and SAE. Although I've never seen it, there could be a SAE 10-30 that would would be a "heavier weight"
I would be very interested in reading more if you can provide a link on the API or SAE's web site.
-Dennis
You can do your own homework:
SAE W designation
API Winter Designation
popped into jiffy lube years ago for a quick change, yes, i was young and uninformed.... first thing they asked? what weight of oil you want? when i asked what he meant, he tried giving me a complete history on weight of oils, and told me the W means weight....fortunately i wasnt a total fool, and knew better.
asked my local mechanic about this, he grinned, but even he said, thanks too the average joe/jane using quick lube shops, and there employees lack of knowing anything about the prodicts they are handling, they pass along wrong information all the time, and we now have a generation of young adults not knowing what oil may be good or bad for there application. not ALL of the fault is on quick lube shops, but they certainly havnt helped either.
asked my local mechanic about this, he grinned, but even he said, thanks too the average joe/jane using quick lube shops, and there employees lack of knowing anything about the prodicts they are handling, they pass along wrong information all the time, and we now have a generation of young adults not knowing what oil may be good or bad for there application. not ALL of the fault is on quick lube shops, but they certainly havnt helped either.
Originally Posted By: tom slick
Originally Posted By: bluesubie
Originally Posted By: tom slick
Originally Posted By: bluesubie
It's just one of those things that happens in oil folklore. Just like people thinking that the "w" stands for winter when apparently it only denotes a multi-viscosity oil amd doesn't stand for anything (based on what I've read here). Or like people thinking that there was a judge's ruling based on a lawsuit that Mobil brought against Castrol.
-Dennis
"W" does stand for "Winter" according to API and SAE. Although I've never seen it, there could be a SAE 10-30 that would would be a "heavier weight"
when cold than a 10w30.
I would be very interested in reading more if you can provide a link on the API or SAE's web site.
-Dennis
You can do your own homework:
SAE W designation
API Winter Designation
So in other words, you don't know. I'm still looking for a document that specifically states "W" stands for winter (not that it denotes multi-viscosity oil for winter usage).
Quote:
To correct this problem, a new low-temperature classification was eventually added to the Standard in 1950, and it became possible to grade oils by a low-temperature W-grade designation, such as SAE 5W, 10W, or 20W. Now the consumer could ask specifically for an SAE 5W grade, at that time the lowest of the three low-viscosity SAE W-grades, for cold weather driving, or an SAE 40 grade, for example, for summer operation.
http://www.sae.org/news/releases/rightoil.htm
-Dennis
Originally Posted By: bluesubie
Originally Posted By: tom slick
Originally Posted By: bluesubie
It's just one of those things that happens in oil folklore. Just like people thinking that the "w" stands for winter when apparently it only denotes a multi-viscosity oil amd doesn't stand for anything (based on what I've read here). Or like people thinking that there was a judge's ruling based on a lawsuit that Mobil brought against Castrol.
-Dennis
"W" does stand for "Winter" according to API and SAE. Although I've never seen it, there could be a SAE 10-30 that would would be a "heavier weight"
I would be very interested in reading more if you can provide a link on the API or SAE's web site.
-Dennis
You can do your own homework:
SAE W designation
API Winter Designation
So in other words, you don't know. I'm still looking for a document that specifically states "W" stands for winter (not that it denotes multi-viscosity oil for winter usage).
Quote:
To correct this problem, a new low-temperature classification was eventually added to the Standard in 1950, and it became possible to grade oils by a low-temperature W-grade designation, such as SAE 5W, 10W, or 20W. Now the consumer could ask specifically for an SAE 5W grade, at that time the lowest of the three low-viscosity SAE W-grades, for cold weather driving, or an SAE 40 grade, for example, for summer operation.
http://www.sae.org/news/releases/rightoil.htm
-Dennis
Last edited:
Originally Posted By: Burt
Next time when your wife asks if this outfit makes her look fat, say, no honey, just a little more viscous.
Don't say "I've seen FATTER".
Next time when your wife asks if this outfit makes her look fat, say, no honey, just a little more viscous.
Don't say "I've seen FATTER".
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