What does it mean if an oil is SAE 10 or SAE 5? How does that differ from, say, 5w-30 or 10w-30
Oil weight question
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Originally Posted By: gregk24
The First number is the winter rating. If it's just sae 20...sae 30 etc, it's just a straight weight oil
So how is it different from the multi-grade oils in terms of thickness/thinness.
Using straight 10 weight, it is thicker or thinner than 5w-30 or 10w-30?
The First number is the winter rating. If it's just sae 20...sae 30 etc, it's just a straight weight oil
So how is it different from the multi-grade oils in terms of thickness/thinness.
Using straight 10 weight, it is thicker or thinner than 5w-30 or 10w-30?
Single grade vs multi grade.
SAE30 is single grade, 5w20 is multi grade, grade 5 at low temp and grade 30 at engine operating temp (approx 212F).
SAE30 is single grade, 5w20 is multi grade, grade 5 at low temp and grade 30 at engine operating temp (approx 212F).
There is no 10 weight. There is a 10W spec that is part of 10W-40, 10W-30, etc.
Here's the SAE J300 chart for motor oil viscosities:
http://www.infineum.com/Documents/API/SAE Viscosity Grades for Engine Oils 2010.pdf
Note the low temperature specifications for all oil viscosity grades with a "W" (for winter) as part of the grade. Note the high temperature specs for oil viscosity grades without the W. You'll see that a 5W (part of, say, 5W-30) meets a lower temperature spec than 10W (of 10W-30). And that a 20 (as part of, say, 5W-20) is thinner at high temperature than a 30 (of 5W-30).
So, the designers of your engine picked an oil viscosity grade that gave them the oil pumpability and flow at cold temperatures and the viscosity for protection at high temperatures that the engine needed.
Here's the SAE J300 chart for motor oil viscosities:
http://www.infineum.com/Documents/API/SAE Viscosity Grades for Engine Oils 2010.pdf
Note the low temperature specifications for all oil viscosity grades with a "W" (for winter) as part of the grade. Note the high temperature specs for oil viscosity grades without the W. You'll see that a 5W (part of, say, 5W-30) meets a lower temperature spec than 10W (of 10W-30). And that a 20 (as part of, say, 5W-20) is thinner at high temperature than a 30 (of 5W-30).
So, the designers of your engine picked an oil viscosity grade that gave them the oil pumpability and flow at cold temperatures and the viscosity for protection at high temperatures that the engine needed.
Also the winter ratings are only comparable to other winter ratings. All oil is thicker at lower tempertures. a 0w20 100F is still much thicker than an SAE 50 @ 212F. An SAE 50 will be approx 22 cSt @ 100C, while the 0w20 will be between 61-74 cSt @ 100F.
A 5w30 is superior to a 10w30 in below freezing viscosity, and a 10w30 is superior to a 10w40 below freezing also. A 0w30 will be superior at extremely cold tempertures below 0F.
All oil is too thick to properly lubricate until it reachs sufficient temperatures of closer to 100C.
A 5w30 is superior to a 10w30 in below freezing viscosity, and a 10w30 is superior to a 10w40 below freezing also. A 0w30 will be superior at extremely cold tempertures below 0F.
All oil is too thick to properly lubricate until it reachs sufficient temperatures of closer to 100C.
Originally Posted By: dan765
What does it mean if an oil is SAE 10 or SAE 5? How does that differ from, say, 5w-30 or 10w-30
SAE J300 is lacking a lot of stuff. There is no sae 5 or sae 10. Therefore it is incorrect labeling.
These single grades should correctly show sae5W or sae10W and they will have to be winter ready (for their respective W rating).
Whatever the case, there are no polymeric thickeners allowed with single grades. So what you see is actually what you get.
What does it mean if an oil is SAE 10 or SAE 5? How does that differ from, say, 5w-30 or 10w-30
SAE J300 is lacking a lot of stuff. There is no sae 5 or sae 10. Therefore it is incorrect labeling.
These single grades should correctly show sae5W or sae10W and they will have to be winter ready (for their respective W rating).
Whatever the case, there are no polymeric thickeners allowed with single grades. So what you see is actually what you get.
Nick1994
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SAE 10 is a 10 weight all the time. 5W-30 is a cold 5 weight and a hot 30 weight. Plain and simple.
So if I'm understanding right:
At some designated low temperature, a 5W30 will have the same viscosity as an SAE 5 (if there was a thing).
When up to operating temperature, the 5W30 will be the same viscosity as an SAE30.
That doesn't seem right to me, for example, I didn't think that a 0W40 would be the same viscosity as a 0W30 at the same designated low temperature.
At some designated low temperature, a 5W30 will have the same viscosity as an SAE 5 (if there was a thing).
When up to operating temperature, the 5W30 will be the same viscosity as an SAE30.
That doesn't seem right to me, for example, I didn't think that a 0W40 would be the same viscosity as a 0W30 at the same designated low temperature.
It wouldn't be right according to what I understand...that is it is harder to achieve the 0 rating as a 30 vs a 40...so they are different at low temp
you are understanding it right (mostly)
the thing about the words viscosity and grade it can be sometimes difficult to see the forest through the trees so to speak. Each GRADE of SAE VISCOSITY is a range based on specified tests for cold temperature and operating temperature, and they don't really cross over each other.
The Number on the bottle is divided into 2 parts: XW and XX
XW is a GRADE based on a cold flow test which allows a range. The lowest possible XW rating for the oil must be shown - so all 5W oils must be within the established range at the for the results of the cold temperature test. 0W oils are the next range down. so if you have a 0W30 and a 0W40, they may not be the exact same viscosity at the designated temperature, but they fall into the same range (both lower than the minimum thickness to qualify for a 5W grade) by the CCS and MRV tests.
The XX correlates more directly with strait grade oils, again based on the range established by the KV100. The lightest possible number on this scale is SAE20, soon to be replaced by SAE16 when the next round of oils comes out.
The numbers for the ranges are available in many places but the source is the SAE J300. It's understanding the difference in the ranges that is important. The numbers are just a designation to the ranges.
the thing about the words viscosity and grade it can be sometimes difficult to see the forest through the trees so to speak. Each GRADE of SAE VISCOSITY is a range based on specified tests for cold temperature and operating temperature, and they don't really cross over each other.
The Number on the bottle is divided into 2 parts: XW and XX
XW is a GRADE based on a cold flow test which allows a range. The lowest possible XW rating for the oil must be shown - so all 5W oils must be within the established range at the for the results of the cold temperature test. 0W oils are the next range down. so if you have a 0W30 and a 0W40, they may not be the exact same viscosity at the designated temperature, but they fall into the same range (both lower than the minimum thickness to qualify for a 5W grade) by the CCS and MRV tests.
The XX correlates more directly with strait grade oils, again based on the range established by the KV100. The lightest possible number on this scale is SAE20, soon to be replaced by SAE16 when the next round of oils comes out.
The numbers for the ranges are available in many places but the source is the SAE J300. It's understanding the difference in the ranges that is important. The numbers are just a designation to the ranges.
Originally Posted By: dan765
Originally Posted By: gregk24
The First number is the winter rating. If it's just sae 20...sae 30 etc, it's just a straight weight oil
So how is it different from the multi-grade oils in terms of thickness/thinness.
Using straight 10 weight, it is thicker or thinner than 5w-30 or 10w-30?
You're doing what almost everyone does when they first start trying to think about multi-grade oils: thinking of it as it pours out of the bottle and trying to decide whether a 10w30 or SAE 30 should "look thicker" and assess how they perform in the engine accordingly.
Forget that.
The oil viscosity rating is the SECOND number. So a 10w30 and an SAE 30 and a 0w30 and a 5w30 are ALL 30 grade oils. What that means is that at a standard temperature intended to more-or-less correspond to the OPERATING temperature of the oil (in other words, hot!), they are all within the range of viscosity that the SAE designates as a 30 weight oil. They're all about the same when hot.
So why are they different? Well, what happens when you cool each one of them off, going DOWN in temperature from that operating temperature where they are all the same. This is where they become different. The lower the FIRST number, the LESS the oil is allowed to thicken up as it cools down to the sub-freezing point where the cold characteristics of the oil are measured.
So turn your thinking upside down. Start with the oil HOT, which is what the engine experiences most of the time its operating. The 2nd number indicates how thick it will be, the first number indicates how much thickER it is allowed to become as it cools. A 0w30 oil changes less as it cools than a 10w30 is allowed to. That's why, contrary to most people's first impression, there's nothing at all with running a 0w30 in Death Valley towing a trailer in the middle of summer. Its STILL a 30-weight oil, assuming its formulated well enough that it doesn't break down (and most modern oils are).
Originally Posted By: gregk24
The First number is the winter rating. If it's just sae 20...sae 30 etc, it's just a straight weight oil
So how is it different from the multi-grade oils in terms of thickness/thinness.
Using straight 10 weight, it is thicker or thinner than 5w-30 or 10w-30?
You're doing what almost everyone does when they first start trying to think about multi-grade oils: thinking of it as it pours out of the bottle and trying to decide whether a 10w30 or SAE 30 should "look thicker" and assess how they perform in the engine accordingly.
Forget that.
The oil viscosity rating is the SECOND number. So a 10w30 and an SAE 30 and a 0w30 and a 5w30 are ALL 30 grade oils. What that means is that at a standard temperature intended to more-or-less correspond to the OPERATING temperature of the oil (in other words, hot!), they are all within the range of viscosity that the SAE designates as a 30 weight oil. They're all about the same when hot.
So why are they different? Well, what happens when you cool each one of them off, going DOWN in temperature from that operating temperature where they are all the same. This is where they become different. The lower the FIRST number, the LESS the oil is allowed to thicken up as it cools down to the sub-freezing point where the cold characteristics of the oil are measured.
So turn your thinking upside down. Start with the oil HOT, which is what the engine experiences most of the time its operating. The 2nd number indicates how thick it will be, the first number indicates how much thickER it is allowed to become as it cools. A 0w30 oil changes less as it cools than a 10w30 is allowed to. That's why, contrary to most people's first impression, there's nothing at all with running a 0w30 in Death Valley towing a trailer in the middle of summer. Its STILL a 30-weight oil, assuming its formulated well enough that it doesn't break down (and most modern oils are).
Originally Posted By: Merkava_4
SAE 10 is a 10 weight all the time. 5W-30 is a cold 5 weight and a hot 30 weight. Plain and simple.
No, not true!
5w is the winter rating! The oil is much thicker cold than hot. The second number is the viscosity at 100C. An SAE 30, 0w30, 5w30, and 10w30 will all fall within the viscosity range specified of 9.3 cSt - 12.5 cSt @ 100C range, but...
The SAE 30 will be impossible to crank below 0F.
The 0w30 will crank down to probably -30F or so (Maybe colder!)
The 5w30 will crank down to probably -25F for a mineral oil
The 10w30 will crank down to probably 20F or so.
None of the figures for cranking are "exact" but giving you a rough example to help you understand.
SAE 10 is a 10 weight all the time. 5W-30 is a cold 5 weight and a hot 30 weight. Plain and simple.
No, not true!
5w is the winter rating! The oil is much thicker cold than hot. The second number is the viscosity at 100C. An SAE 30, 0w30, 5w30, and 10w30 will all fall within the viscosity range specified of 9.3 cSt - 12.5 cSt @ 100C range, but...
The SAE 30 will be impossible to crank below 0F.
The 0w30 will crank down to probably -30F or so (Maybe colder!)
The 5w30 will crank down to probably -25F for a mineral oil
The 10w30 will crank down to probably 20F or so.
None of the figures for cranking are "exact" but giving you a rough example to help you understand.
Originally Posted By: 901Memphis
No, not true!
It is very much true and I was able to explain it in one sentence like this one.
No, not true!
It is very much true and I was able to explain it in one sentence like this one.
Originally Posted By: 901Memphis
The SAE 30 will be impossible to crank below 0F.
The 0w30 will crank down to probably -30F or so (Maybe colder!)
The 5w30 will crank down to probably -25F for a mineral oil
The 10w30 will crank down to probably 20F or so.
None of the figures for cranking are "exact" but giving you a rough example to help you understand. .
Great charts. Actually, an oil might crank down to its pour point, as long as its a liquid. The xW designations only tell us how difficult it will be to crank, smaller numbers meaning it will be less difficult at those very cold temperatures, as your chart shows. However, a 5w-30 will be more difficult to crank at, say, 10 degF, than a 5w-20, as they both have the "5w" rating for cranking difficulty at the extremely cold temperatures only.
The SAE 30 will be impossible to crank below 0F.
The 0w30 will crank down to probably -30F or so (Maybe colder!)
The 5w30 will crank down to probably -25F for a mineral oil
The 10w30 will crank down to probably 20F or so.
None of the figures for cranking are "exact" but giving you a rough example to help you understand. .
Great charts. Actually, an oil might crank down to its pour point, as long as its a liquid. The xW designations only tell us how difficult it will be to crank, smaller numbers meaning it will be less difficult at those very cold temperatures, as your chart shows. However, a 5w-30 will be more difficult to crank at, say, 10 degF, than a 5w-20, as they both have the "5w" rating for cranking difficulty at the extremely cold temperatures only.
Originally Posted By: Merkava_4
SAE 10 is a 10 weight all the time. 5W-30 is a cold 5 weight and a hot 30 weight. Plain and simple.
I'm sure it makes sense in your head but to the rest of the world your stating that the 5w30 is thinner when cold than hot which isn't true.
http://www.sae.org/news/releases/rightoil.htm
SAE 10 is a 10 weight all the time. 5W-30 is a cold 5 weight and a hot 30 weight. Plain and simple.
I'm sure it makes sense in your head but to the rest of the world your stating that the 5w30 is thinner when cold than hot which isn't true.
http://www.sae.org/news/releases/rightoil.htm
Originally Posted By: 901Memphis
The SAE 30 will be impossible to crank below 0F.
That's not 100% accurate. SAE 30 just means its VII free and says nothing about its cold performance.
The SAE 30 will be impossible to crank below 0F.
That's not 100% accurate. SAE 30 just means its VII free and says nothing about its cold performance.
Originally Posted By: 440Magnum
The oil viscosity rating is the SECOND number. So a 10w30 and an SAE 30 and a 0w30 and a 5w30 are ALL 30 grade oils. What that means is that at a standard temperature intended to more-or-less correspond to the OPERATING temperature of the oil (in other words, hot!), they are all within the range of viscosity that the SAE designates as a 30 weight oil. They're all about the same when hot.
So why are they different? Well, what happens when you cool each one of them off, going DOWN in temperature from that operating temperature where they are all the same. This is where they become different. The lower the FIRST number, the LESS the oil is allowed to thicken up as it cools down to the sub-freezing point where the cold characteristics of the oil are measured.
So turn your thinking upside down. Start with the oil HOT, which is what the engine experiences most of the time its operating. The 2nd number indicates how thick it will be, the first number indicates how much thickER it is allowed to become as it cools. A 0w30 oil changes less as it cools than a 10w30 is allowed to. That's why, contrary to most people's first impression, there's nothing at all with running a 0w30 in Death Valley towing a trailer in the middle of summer. Its STILL a 30-weight oil, assuming its formulated well enough that it doesn't break down (and most modern oils are).
I agree this is the best way to think about it.
The oil viscosity rating is the SECOND number. So a 10w30 and an SAE 30 and a 0w30 and a 5w30 are ALL 30 grade oils. What that means is that at a standard temperature intended to more-or-less correspond to the OPERATING temperature of the oil (in other words, hot!), they are all within the range of viscosity that the SAE designates as a 30 weight oil. They're all about the same when hot.
So why are they different? Well, what happens when you cool each one of them off, going DOWN in temperature from that operating temperature where they are all the same. This is where they become different. The lower the FIRST number, the LESS the oil is allowed to thicken up as it cools down to the sub-freezing point where the cold characteristics of the oil are measured.
So turn your thinking upside down. Start with the oil HOT, which is what the engine experiences most of the time its operating. The 2nd number indicates how thick it will be, the first number indicates how much thickER it is allowed to become as it cools. A 0w30 oil changes less as it cools than a 10w30 is allowed to. That's why, contrary to most people's first impression, there's nothing at all with running a 0w30 in Death Valley towing a trailer in the middle of summer. Its STILL a 30-weight oil, assuming its formulated well enough that it doesn't break down (and most modern oils are).
I agree this is the best way to think about it.
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