M1 10W30 : Why Such Low Viscosity Index ?
- Thread starter ChrisD46
- Start date
- Status
I don't claim to be an expert, but the way I understand it is the higher the VI, the more VII improvers are in the oil (the oil is propped up more). Because 10w30 is closer in grade than the 5w30, it doesn't need the VII improvers to help prop it up, thus having a naturally lower VI. I'm willing to bet the 10w30 has a much lower NOACK than the 5w30 also because it doesn't need all the "help" to make the grade like the 5w30 does.
I'm also curious. I believe that lower viscosity oils improves the fuel efficiency and offered more protection so I think the M1 10W30 is intended to provide those benefits.
OVERKILL
$100 Site Donor 2021
Originally Posted By: harryberry
I'm also curious. I believe that lower viscosity oils improves the fuel efficiency and offered more protection so I think the M1 10W30 is intended to provide those benefits.
They are talking about viscosity index, not viscosity. M1 10w30 is not a "low viscosity" product.
I'm also curious. I believe that lower viscosity oils improves the fuel efficiency and offered more protection so I think the M1 10W30 is intended to provide those benefits.
They are talking about viscosity index, not viscosity. M1 10w30 is not a "low viscosity" product.
Originally Posted By: OVERKILL
Originally Posted By: harryberry
I'm also curious. I believe that lower viscosity oils improves the fuel efficiency and offered more protection so I think the M1 10W30 is intended to provide those benefits.
They are talking about viscosity index, not viscosity. M1 10w30 is not a "low viscosity" product.
Surprisingly enough, M1 10W30 has lower HTHS and 100C viscosities than M1 5W30, going by the Mobil website.
https://mobiloil.com/en/motor-oils/mobil-1/mobil-1
Originally Posted By: harryberry
I'm also curious. I believe that lower viscosity oils improves the fuel efficiency and offered more protection so I think the M1 10W30 is intended to provide those benefits.
They are talking about viscosity index, not viscosity. M1 10w30 is not a "low viscosity" product.
Surprisingly enough, M1 10W30 has lower HTHS and 100C viscosities than M1 5W30, going by the Mobil website.
https://mobiloil.com/en/motor-oils/mobil-1/mobil-1
OVERKILL
$100 Site Donor 2021
Originally Posted By: Virtus_Probi
Originally Posted By: OVERKILL
Originally Posted By: harryberry
I'm also curious. I believe that lower viscosity oils improves the fuel efficiency and offered more protection so I think the M1 10W30 is intended to provide those benefits.
They are talking about viscosity index, not viscosity. M1 10w30 is not a "low viscosity" product.
Surprisingly enough, M1 10W30 has lower HTHS and 100C viscosities than M1 5W30, going by the Mobil website.
https://mobiloil.com/en/motor-oils/mobil-1/mobil-1
Not really surprising, it is probably based lighter with far less VII in it (hence the low VI).
Originally Posted By: OVERKILL
Originally Posted By: harryberry
I'm also curious. I believe that lower viscosity oils improves the fuel efficiency and offered more protection so I think the M1 10W30 is intended to provide those benefits.
They are talking about viscosity index, not viscosity. M1 10w30 is not a "low viscosity" product.
Surprisingly enough, M1 10W30 has lower HTHS and 100C viscosities than M1 5W30, going by the Mobil website.
https://mobiloil.com/en/motor-oils/mobil-1/mobil-1
Not really surprising, it is probably based lighter with far less VII in it (hence the low VI).
Precisely because it's a 10w30 - meaning: narrower viscosity spread. If it had a higher VI, it would have been classified as a 5w30 or a 10w-40...
Last edited:
Originally Posted By: Virtus_Probi
Originally Posted By: OVERKILL
Originally Posted By: harryberry
I'm also curious. I believe that lower viscosity oils improves the fuel efficiency and offered more protection so I think the M1 10W30 is intended to provide those benefits.
They are talking about viscosity index, not viscosity. M1 10w30 is not a "low viscosity" product.
Surprisingly enough, M1 10W30 has lower HTHS and 100C viscosities than M1 5W30, going by the Mobil website.
https://mobiloil.com/en/motor-oils/mobil-1/mobil-1
Makes no sense the 100C viscosities are different, they're both 30w oils, they should be nearly identical at 100C. The 40C viscosities should be where the big difference is, not 100C. Makes me question if their numbers are correct on the website.
Originally Posted By: OVERKILL
Originally Posted By: harryberry
I'm also curious. I believe that lower viscosity oils improves the fuel efficiency and offered more protection so I think the M1 10W30 is intended to provide those benefits.
They are talking about viscosity index, not viscosity. M1 10w30 is not a "low viscosity" product.
Surprisingly enough, M1 10W30 has lower HTHS and 100C viscosities than M1 5W30, going by the Mobil website.
https://mobiloil.com/en/motor-oils/mobil-1/mobil-1
Makes no sense the 100C viscosities are different, they're both 30w oils, they should be nearly identical at 100C. The 40C viscosities should be where the big difference is, not 100C. Makes me question if their numbers are correct on the website.
Originally Posted By: Fasttimez
Makes no sense the 100C viscosities are different, they're both 30w oils, they should be nearly identical at 100C.
There isn't a whole lot of difference between 10.1 and 11 cSt at 100C.
Makes no sense the 100C viscosities are different, they're both 30w oils, they should be nearly identical at 100C.
There isn't a whole lot of difference between 10.1 and 11 cSt at 100C.
Originally Posted By: Quattro Pete
Originally Posted By: Fasttimez
Makes no sense the 100C viscosities are different, they're both 30w oils, they should be nearly identical at 100C.
There isn't a whole lot of difference between 10.1 and 11 cSt at 100C.
That's a big spread for the same weight oil for 100C Visc. Usually the spread will be biggest at 40C because of the 5w vs 10W properties. Pennzoil Platinum for example 5w30 & 10W30 have the exact same 100C Visc numbers. There are numerous other oils that are the same way. Something just doesn't seem right about those 100C numbers for Mobil 1.
Originally Posted By: Fasttimez
Makes no sense the 100C viscosities are different, they're both 30w oils, they should be nearly identical at 100C.
There isn't a whole lot of difference between 10.1 and 11 cSt at 100C.
That's a big spread for the same weight oil for 100C Visc. Usually the spread will be biggest at 40C because of the 5w vs 10W properties. Pennzoil Platinum for example 5w30 & 10W30 have the exact same 100C Visc numbers. There are numerous other oils that are the same way. Something just doesn't seem right about those 100C numbers for Mobil 1.
OVERKILL
$100 Site Donor 2021
Originally Posted By: Fasttimez
Originally Posted By: Quattro Pete
Originally Posted By: Fasttimez
Makes no sense the 100C viscosities are different, they're both 30w oils, they should be nearly identical at 100C.
There isn't a whole lot of difference between 10.1 and 11 cSt at 100C.
That's a big spread for the same weight oil for 100C Visc. Usually the spread will be biggest at 40C because of the 5w vs 10W properties. Pennzoil Platinum for example 5w30 & 10W30 have the exact same 100C Visc numbers. There are numerous other oils that are the same way. Something just doesn't seem right about those 100C numbers for Mobil 1.
Grades are a range. Both oils are well within that range, ergo they both get to be 30's. It's really of no consequence that the 10w30 is slightly lighter at 100C.
Originally Posted By: Quattro Pete
Originally Posted By: Fasttimez
Makes no sense the 100C viscosities are different, they're both 30w oils, they should be nearly identical at 100C.
There isn't a whole lot of difference between 10.1 and 11 cSt at 100C.
That's a big spread for the same weight oil for 100C Visc. Usually the spread will be biggest at 40C because of the 5w vs 10W properties. Pennzoil Platinum for example 5w30 & 10W30 have the exact same 100C Visc numbers. There are numerous other oils that are the same way. Something just doesn't seem right about those 100C numbers for Mobil 1.
Grades are a range. Both oils are well within that range, ergo they both get to be 30's. It's really of no consequence that the 10w30 is slightly lighter at 100C.
Originally Posted By: OVERKILL
Originally Posted By: Fasttimez
Originally Posted By: Quattro Pete
Originally Posted By: Fasttimez
Makes no sense the 100C viscosities are different, they're both 30w oils, they should be nearly identical at 100C.
There isn't a whole lot of difference between 10.1 and 11 cSt at 100C.
That's a big spread for the same weight oil for 100C Visc. Usually the spread will be biggest at 40C because of the 5w vs 10W properties. Pennzoil Platinum for example 5w30 & 10W30 have the exact same 100C Visc numbers. There are numerous other oils that are the same way. Something just doesn't seem right about those 100C numbers for Mobil 1.
Grades are a range. Both oils are well within that range, ergo they both get to be 30's. It's really of no consequence that the 10w30 is slightly lighter at 100C.
You would think if both are derived from the same base stock, only difference being the VII & some additives to achieve the 5w rating, the 100C Visc should be nearly identical if not the same. Makes you wonder if the 5w30 & 10w30 are completely different base stock oils.
Originally Posted By: Fasttimez
Originally Posted By: Quattro Pete
Originally Posted By: Fasttimez
Makes no sense the 100C viscosities are different, they're both 30w oils, they should be nearly identical at 100C.
There isn't a whole lot of difference between 10.1 and 11 cSt at 100C.
That's a big spread for the same weight oil for 100C Visc. Usually the spread will be biggest at 40C because of the 5w vs 10W properties. Pennzoil Platinum for example 5w30 & 10W30 have the exact same 100C Visc numbers. There are numerous other oils that are the same way. Something just doesn't seem right about those 100C numbers for Mobil 1.
Grades are a range. Both oils are well within that range, ergo they both get to be 30's. It's really of no consequence that the 10w30 is slightly lighter at 100C.
You would think if both are derived from the same base stock, only difference being the VII & some additives to achieve the 5w rating, the 100C Visc should be nearly identical if not the same. Makes you wonder if the 5w30 & 10w30 are completely different base stock oils.
Originally Posted By: Fasttimez
Originally Posted By: Quattro Pete
Originally Posted By: Fasttimez
Makes no sense the 100C viscosities are different, they're both 30w oils, they should be nearly identical at 100C.
There isn't a whole lot of difference between 10.1 and 11 cSt at 100C.
That's a big spread for the same weight oil for 100C Visc.
Just to put things in perspective a little bit, an oil like M1 10w30 that has viscosity of 10.1 cSt at 100C will have viscosity of 11 cSt at 96C. That's barely a 4 degree difference. Most engines run at wide range of operating temps, where the oil temp can be anywhere from 180F all the way up to 250F, so again, a difference of 0.9 cSt at 100C is meaningless, IMO.
Oil formulators choose how to design oils for each grade. There is no mandate that a 5w30 has to have the exact same viscosity at 100C as a 10w30 or as a 0w-30.
My guess is that a 5w30 is going to be formulated to have just slightly higher 100C viscosity because it is typically less shear stable, so even if it does shear a bit, it will still stay within a 30-grade range. For 10w30 grades, that's usually less of a problem.
Originally Posted By: Quattro Pete
Originally Posted By: Fasttimez
Makes no sense the 100C viscosities are different, they're both 30w oils, they should be nearly identical at 100C.
There isn't a whole lot of difference between 10.1 and 11 cSt at 100C.
That's a big spread for the same weight oil for 100C Visc.
Just to put things in perspective a little bit, an oil like M1 10w30 that has viscosity of 10.1 cSt at 100C will have viscosity of 11 cSt at 96C. That's barely a 4 degree difference. Most engines run at wide range of operating temps, where the oil temp can be anywhere from 180F all the way up to 250F, so again, a difference of 0.9 cSt at 100C is meaningless, IMO.
Oil formulators choose how to design oils for each grade. There is no mandate that a 5w30 has to have the exact same viscosity at 100C as a 10w30 or as a 0w-30.
My guess is that a 5w30 is going to be formulated to have just slightly higher 100C viscosity because it is typically less shear stable, so even if it does shear a bit, it will still stay within a 30-grade range. For 10w30 grades, that's usually less of a problem.
Originally Posted By: Fasttimez
You would think if both are derived from the same base stock, only difference being the VII & some additives
Multiple oil bases are combined to achieve the desired end viscosity. See this sample formulation guide that Shannow posted some time ago...
You would think if both are derived from the same base stock, only difference being the VII & some additives
Multiple oil bases are combined to achieve the desired end viscosity. See this sample formulation guide that Shannow posted some time ago...
Cool info to see. In real world practicality, I was also told that the difference between a 5W & 10W is only about 15*F. Meaning you only gain about 15*F of temperature going from a 10w to a 5w. So what a 10w will do at 0*F, a 5w will do the same at -15*F. If that's true, besides CAFE requirements, what is the real advantage of using a 5w vs a 10w oil ?
OVERKILL
$100 Site Donor 2021
Originally Posted By: Fasttimez
Cool info to see. In real world practicality, I was also told that the difference between a 5W & 10W is only about 15*F. Meaning you only gain about 15*F of temperature going from a 10w to a 5w. So what a 10w will do at 0*F, a 5w will do the same at -15*F. If that's true, besides CAFE requirements, what is the real advantage of using a 5w vs a 10w oil ?
If you live where it gets cold, it matters. If you don't, it matters far less.
Cool info to see. In real world practicality, I was also told that the difference between a 5W & 10W is only about 15*F. Meaning you only gain about 15*F of temperature going from a 10w to a 5w. So what a 10w will do at 0*F, a 5w will do the same at -15*F. If that's true, besides CAFE requirements, what is the real advantage of using a 5w vs a 10w oil ?
If you live where it gets cold, it matters. If you don't, it matters far less.
Originally Posted By: OVERKILL
Originally Posted By: Fasttimez
Cool info to see. In real world practicality, I was also told that the difference between a 5W & 10W is only about 15*F. Meaning you only gain about 15*F of temperature going from a 10w to a 5w. So what a 10w will do at 0*F, a 5w will do the same at -15*F. If that's true, besides CAFE requirements, what is the real advantage of using a 5w vs a 10w oil ?
If you live where it gets cold, it matters. If you don't, it matters far less.
Exactly. Here in southeastern Wisconsin in the summer it doesn't make one bit of difference. In the winter it makes some difference, especially when it gets below zero F. For my BMW which lives in northern Wisconsin where it regularly gets to -25F and below, it matters a lot. Now that doesn't mean the car won't start, but it sure makes a difference.
But am I supposed to be concerned about viscosity index? Because I'm not, I just go with required specifications and a grade that is appropriate for the weather. What am I missing out on by not being concerned about viscosity index?
Originally Posted By: Fasttimez
Cool info to see. In real world practicality, I was also told that the difference between a 5W & 10W is only about 15*F. Meaning you only gain about 15*F of temperature going from a 10w to a 5w. So what a 10w will do at 0*F, a 5w will do the same at -15*F. If that's true, besides CAFE requirements, what is the real advantage of using a 5w vs a 10w oil ?
If you live where it gets cold, it matters. If you don't, it matters far less.
Exactly. Here in southeastern Wisconsin in the summer it doesn't make one bit of difference. In the winter it makes some difference, especially when it gets below zero F. For my BMW which lives in northern Wisconsin where it regularly gets to -25F and below, it matters a lot. Now that doesn't mean the car won't start, but it sure makes a difference.
But am I supposed to be concerned about viscosity index? Because I'm not, I just go with required specifications and a grade that is appropriate for the weather. What am I missing out on by not being concerned about viscosity index?
And one person's idea of cold is another person's idea of nippy. Unless one is dealing with some ambient temps in the sub zero category, a 10w30 will work just fine. It works just fine even for me when temps get in the teens below zero, which is only limited number of days a year.
OP here - not to beat the GDI dead horse - but M1 10W30 in a southern state is of interest due to low NOACK (M1 10W30 ?) and new information indicating VII's can be just as detremental to intake valve deposits as a high NOACK oil . Thus the lowest NOACK + the least VII's in a oil for a GDI engine is deemed the best (along with low calcium to curtail LSPI)should make M1 10W30 a serious contender.
Last edited:
If cold cranking is not a factor in your location I don't see a reason to run a 5w or 0w
Unless we are talking about a hybrid. They have different needs and operating conditions. I could see the benefits of a thin 0w-20 for an engine that doesn't run continuously and may not reach full operating temp. The cold mans version of a 30 weight
Unless we are talking about a hybrid. They have different needs and operating conditions. I could see the benefits of a thin 0w-20 for an engine that doesn't run continuously and may not reach full operating temp. The cold mans version of a 30 weight
- Status