Is 10w30 thinner than 0w40 at 40c?
- Thread starter DinoLover
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Yes, M1 is a 40 grade oil and the QSUD is a 30 grade.
Not surprising since the cold cranking viscosity of oil is measured at very low temps. -35C in the case of 0W oils and -25C for 10W oils.
M1 0W-40 is thinner than QSUD 10W-30 when the temps get below 0C. QS Defy is thicker at 0C than M1 0W-40, M1 10W-30 HM, and QSUD 10W-30. We could keep playing this.
-Dennis
M1 0W-40 is thinner than QSUD 10W-30 when the temps get below 0C. QS Defy is thicker at 0C than M1 0W-40, M1 10W-30 HM, and QSUD 10W-30. We could keep playing this.
-Dennis
Yes I understand, but I think the point I'm making is that a 10w30 might be better for you than a 0w40 for cold starts at certain temps.
I think a measure should be introduced that allows us to easily compare the cold start viscosity across a range of temperatures that are meaningful for 80% of circumstances out there.
I think a measure should be introduced that allows us to easily compare the cold start viscosity across a range of temperatures that are meaningful for 80% of circumstances out there.
Originally Posted By: DinoLover
Yes I understand, but I think the point I'm making is that a 10w30 might be better for you than a 0w40 for cold starts at certain temps.
I think a measure should be introduced that allows us to easily compare the cold start viscosity across a range of temperatures that are meaningful for 80% of circumstances out there.
I agree! I ran 0w-40 in my jeep for winter thinking I was doing the jeep a favor over running a 10w-30. I have since learned otherwise. we did have a very mild winter though
Yes I understand, but I think the point I'm making is that a 10w30 might be better for you than a 0w40 for cold starts at certain temps.
I think a measure should be introduced that allows us to easily compare the cold start viscosity across a range of temperatures that are meaningful for 80% of circumstances out there.
I agree! I ran 0w-40 in my jeep for winter thinking I was doing the jeep a favor over running a 10w-30. I have since learned otherwise. we did have a very mild winter though
wait now I'm confused... how is 0w-40 thicker on a cold start than 10w-30?
I thought that was tho whole point of w rating...
I thought that was tho whole point of w rating...
^Depends on the temperature and oil in question.
Pour point vs. the cranking rating, ?
Pour point vs. the cranking rating, ?
Originally Posted By: Texan4Life
wait now I'm confused... how is 0w-40 thicker on a cold start than 10w-30?
I thought that was tho whole point of w rating...
The W rating applies to freezing temperatures. However, when we say "cold start flow" it could mean cold start in the middle of summer in Florida. The 30/40 grade rating applies to fully warmed up temperature, above 200F. At 40C/100F, 10W-30 is actually thinner than most 0W40. Likewise, cold start flow of 5W20 is usually better than that of 0W30. Another interesting observation is that at 40C and even below, 5W20 is usually thinner than 5W30. 5W20's viscosity at 100F is approximately in 45-50cst range, while 5W30s viscosity is in 60-70 range. On the other hand 5W20 and 0W20 cold start flow is about the same, unless we're talking about below freezing temperatures. These viscosities are provided in the product data sheets.
wait now I'm confused... how is 0w-40 thicker on a cold start than 10w-30?
I thought that was tho whole point of w rating...
The W rating applies to freezing temperatures. However, when we say "cold start flow" it could mean cold start in the middle of summer in Florida. The 30/40 grade rating applies to fully warmed up temperature, above 200F. At 40C/100F, 10W-30 is actually thinner than most 0W40. Likewise, cold start flow of 5W20 is usually better than that of 0W30. Another interesting observation is that at 40C and even below, 5W20 is usually thinner than 5W30. 5W20's viscosity at 100F is approximately in 45-50cst range, while 5W30s viscosity is in 60-70 range. On the other hand 5W20 and 0W20 cold start flow is about the same, unless we're talking about below freezing temperatures. These viscosities are provided in the product data sheets.
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Originally Posted By: Zako2
Originally Posted By: Texan4Life
wait now I'm confused... how is 0w-40 thicker on a cold start than 10w-30?
I thought that was tho whole point of w rating...
The W rating applies to freezing temperatures. However, when we say "cold start flow" it could mean cold start in the middle of summer in Florida. The 30/40 grade rating applies to fully warmed up temperature, above 200F. At 40C/100F, 10W-30 is actually thinner than most 0W40. Likewise, cold start flow of 5W20 is usually better than that of 0W30. Another interesting observation is that at 40C and even below, 5W20 is usually thinner than 5W30. 5W20's viscosity at 100F is approximately in 45-50cst range, while 5W30s viscosity is in 60-70 range. On the other hand 5W20 and 0W20 cold start flow is about the same, unless we're talking about below freezing temperatures. These viscosities are provided in the product data sheets.
interesting never thought of it that way. just assumed a lower W performed better at any ambient "cold start" temp.
Originally Posted By: Texan4Life
wait now I'm confused... how is 0w-40 thicker on a cold start than 10w-30?
I thought that was tho whole point of w rating...
The W rating applies to freezing temperatures. However, when we say "cold start flow" it could mean cold start in the middle of summer in Florida. The 30/40 grade rating applies to fully warmed up temperature, above 200F. At 40C/100F, 10W-30 is actually thinner than most 0W40. Likewise, cold start flow of 5W20 is usually better than that of 0W30. Another interesting observation is that at 40C and even below, 5W20 is usually thinner than 5W30. 5W20's viscosity at 100F is approximately in 45-50cst range, while 5W30s viscosity is in 60-70 range. On the other hand 5W20 and 0W20 cold start flow is about the same, unless we're talking about below freezing temperatures. These viscosities are provided in the product data sheets.
interesting never thought of it that way. just assumed a lower W performed better at any ambient "cold start" temp.
^Not just that, but oil formulation can play a role. The base-stocks and varying quality of VII.
Originally Posted By: Texan4Life
wait now I'm confused... how is 0w-40 thicker on a cold start than 10w-30?
I thought that was tho whole point of w rating...
As others have alluded to, one has to look where the 0w and 5w and 10w are measured. 0w is measured at -35 C, 5w at -30 C, and 10w at -25 C for CCV, and for BPV, 0w at -40 C, 5w at -35 C, and 10w at -30 C.
If you're looking for how well and oil flows at less extreme temperatures, one needs to consider the VI.
wait now I'm confused... how is 0w-40 thicker on a cold start than 10w-30?
I thought that was tho whole point of w rating...
As others have alluded to, one has to look where the 0w and 5w and 10w are measured. 0w is measured at -35 C, 5w at -30 C, and 10w at -25 C for CCV, and for BPV, 0w at -40 C, 5w at -35 C, and 10w at -30 C.
If you're looking for how well and oil flows at less extreme temperatures, one needs to consider the VI.
Originally Posted By: DinoLover
I think a measure should be introduced that allows us to easily compare the cold start viscosity across a range of temperatures that are meaningful for 80% of circumstances out there.
I agree! A lot of people (and even some oil companies) dislike the current system because it doesn't factor in HTHS viscosity. I can't see the public accepting a change though. The U.S. didn't accept the metric system! It would be nice to be able to tell kinematic viscosity at 0C, 100C, and HTHS by looking at the bottle.
-Dennis
I think a measure should be introduced that allows us to easily compare the cold start viscosity across a range of temperatures that are meaningful for 80% of circumstances out there.
I agree! A lot of people (and even some oil companies) dislike the current system because it doesn't factor in HTHS viscosity. I can't see the public accepting a change though. The U.S. didn't accept the metric system! It would be nice to be able to tell kinematic viscosity at 0C, 100C, and HTHS by looking at the bottle.
-Dennis
Originally Posted By: Zako2
Originally Posted By: Texan4Life
5W20's viscosity at 100F is approximately in 45-50cst range, while 5W30s viscosity is in 60-70 range. On the other hand 5W20 and 0W20 cold start flow is about the same, unless we're talking about below freezing temperatures.
Except that most 0W-20's have a much higher VI than 5W-20's, that's their main advantage.
For example the Toyota 0W-20 has a KV40 of 37.2cSt and a 216 VI.
So it can be as much as 25% lighter at 40C and 40% lighter at 0C.
For the OP, while QSUD 10W-30 is lighter than M1 0W-30 until the temp's drop below freezing, QSUD 5w30 is lighter at all temp's; 20% so at freezing and more so as the temp's continue to drop.
Originally Posted By: Texan4Life
5W20's viscosity at 100F is approximately in 45-50cst range, while 5W30s viscosity is in 60-70 range. On the other hand 5W20 and 0W20 cold start flow is about the same, unless we're talking about below freezing temperatures.
Except that most 0W-20's have a much higher VI than 5W-20's, that's their main advantage.
For example the Toyota 0W-20 has a KV40 of 37.2cSt and a 216 VI.
So it can be as much as 25% lighter at 40C and 40% lighter at 0C.
For the OP, while QSUD 10W-30 is lighter than M1 0W-30 until the temp's drop below freezing, QSUD 5w30 is lighter at all temp's; 20% so at freezing and more so as the temp's continue to drop.
Correction that's M1 0W-40 of course.
Originally Posted By: webfors
So for climates that rarely see below freezing, 10w30 is *not* obsolete
QSUD 10W-30 with it's 157 VI is one of the better 10W-30 syn's but it still pales in comparison to QSUD 5w30's 172 VI or better still PP 5w30's 177 VI. Since the 10W-30 is the same price as the equally shear resistant 5w30 why would one buy it? I certainly wouldn't, and that'sv why the grade is "obsolete" at least when it comes to synthetic oil.
So for climates that rarely see below freezing, 10w30 is *not* obsolete
QSUD 10W-30 with it's 157 VI is one of the better 10W-30 syn's but it still pales in comparison to QSUD 5w30's 172 VI or better still PP 5w30's 177 VI. Since the 10W-30 is the same price as the equally shear resistant 5w30 why would one buy it? I certainly wouldn't, and that'sv why the grade is "obsolete" at least when it comes to synthetic oil.
Originally Posted By: CATERHAM
Originally Posted By: webfors
So for climates that rarely see below freezing, 10w30 is *not* obsolete
QSUD 10W-30 with it's 157 VI is one of the better 10W-30 syn's but it still pales in comparison to QSUD 5w30's 172 VI or better still PP 5w30's 177 VI. Since the 10W-30 is the same price as the equally shear resistant 5w30 why would one buy it? I certainly wouldn't, and that'sv why the grade is "obsolete" at least when it comes to synthetic oil.
In my turbo application, I would choose the 10W-30 over the 5w30 based on the better volatility (11.1 vs 12.3).
-Dennis
Originally Posted By: webfors
So for climates that rarely see below freezing, 10w30 is *not* obsolete
QSUD 10W-30 with it's 157 VI is one of the better 10W-30 syn's but it still pales in comparison to QSUD 5w30's 172 VI or better still PP 5w30's 177 VI. Since the 10W-30 is the same price as the equally shear resistant 5w30 why would one buy it? I certainly wouldn't, and that'sv why the grade is "obsolete" at least when it comes to synthetic oil.
In my turbo application, I would choose the 10W-30 over the 5w30 based on the better volatility (11.1 vs 12.3).
-Dennis
Originally Posted By: Texan4Life
wait now I'm confused... how is 0w-40 thicker on a cold start than 10w-30?
0W-40 has a higher viscosity at 40dF than 10W-30 has.
You cannot tell the relative startup viscosity by the xxW- number. That number refers to the viscosity way down near -35dF.
Do not confuse oil weight/grade with actual viscosity.
wait now I'm confused... how is 0w-40 thicker on a cold start than 10w-30?
0W-40 has a higher viscosity at 40dF than 10W-30 has.
You cannot tell the relative startup viscosity by the xxW- number. That number refers to the viscosity way down near -35dF.
Do not confuse oil weight/grade with actual viscosity.
All this conversation was part of the reason for my post.
How many people think that with M1 0w40 they are getting good cold start protection because of the "0", when in fact, they are not getting anything much different than the performance of a 10w30 for the cold start temps that most people see.
If there's an argument to use 0w20 instead of 5w20 for a 40% improvement in cold start viscosity, then isn't M1 0w40 over rated compared to QSUD 5w30. Especially if our objective is to avoid wear at start up.
If start up wear is so important, wouldn't it be better to use and change something like QSUD 5w30 at more frequent intervals than use M1 0w40 for less frequent ocis.
How many people think that with M1 0w40 they are getting good cold start protection because of the "0", when in fact, they are not getting anything much different than the performance of a 10w30 for the cold start temps that most people see.
If there's an argument to use 0w20 instead of 5w20 for a 40% improvement in cold start viscosity, then isn't M1 0w40 over rated compared to QSUD 5w30. Especially if our objective is to avoid wear at start up.
If start up wear is so important, wouldn't it be better to use and change something like QSUD 5w30 at more frequent intervals than use M1 0w40 for less frequent ocis.
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