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Would be interesting to contrast the results against the Mobil 1 0w30.....
Amsoil and MPG increase (I know another thread)
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i say to all have fun. clearly amsoil is an excellent product w/ many benefits.
i am happy w/ any discount SM oil i can find.
be it speculative or quantified, amsoil is still a stretch of logic i won't make.
i am happy w/ any discount SM oil i can find.
be it speculative or quantified, amsoil is still a stretch of logic i won't make.
ProStreet, thanks for the pictures of the Dodge Demon. Brings back a lot of good memories. Sounds like your cousin has his act together.
Originally Posted By: Johnny
ProStreet, thanks for the pictures of the Dodge Demon. Brings back a lot of good memories. Sounds like your cousin has his act together.
Your welcome! I figured some of the guys here would enjoy seeing a peice of automotive history. My cousins shop is one of the premeire fabrication shops in this area. He also has 2 guys working for him that are top notch and know just as much as he does. They turn out some great work.
He has always been a huge AMX buff. He is currently putting together a AMX for himself and is shooting to break the record for the worlds fastest AMX. He is looking to go into the 6 second range with this car on AMX power (which is a feat in itself).
ProStreet, thanks for the pictures of the Dodge Demon. Brings back a lot of good memories. Sounds like your cousin has his act together.
Your welcome! I figured some of the guys here would enjoy seeing a peice of automotive history. My cousins shop is one of the premeire fabrication shops in this area. He also has 2 guys working for him that are top notch and know just as much as he does. They turn out some great work.
He has always been a huge AMX buff. He is currently putting together a AMX for himself and is shooting to break the record for the worlds fastest AMX. He is looking to go into the 6 second range with this car on AMX power (which is a feat in itself).
Originally Posted By: TeeDub
The most critical parameter is HT/HS viscosity (lower is better), followed by VI (higher is better). The degree of friction modification is the least important part of the formulation with regards to fuel efficiency....
Do you have any quantitative data that would illustrate that? Whenever I have read comparative testing of different oils' fuel efficiency, friction modification seems to be the most discussed factor. HTHS usually seems to be a relatively minor correlant with FE. I have not seen a VI/FE correlation made before but it does make sense that it would make a difference during warm-up.
I tend to think that HTHS is a complex quality of oil and that any correlation with FE would be imperfect, although I don't doubt its existence.
Also, as I've said before, any oil FE testing I have seen has shown differences between oils of maybe 1-2% or occasionally slightly more. Here we are talking about a difference of much more than that and one that I am personally skeptical of for that reason.
The most critical parameter is HT/HS viscosity (lower is better), followed by VI (higher is better). The degree of friction modification is the least important part of the formulation with regards to fuel efficiency....
Do you have any quantitative data that would illustrate that? Whenever I have read comparative testing of different oils' fuel efficiency, friction modification seems to be the most discussed factor. HTHS usually seems to be a relatively minor correlant with FE. I have not seen a VI/FE correlation made before but it does make sense that it would make a difference during warm-up.
I tend to think that HTHS is a complex quality of oil and that any correlation with FE would be imperfect, although I don't doubt its existence.
Also, as I've said before, any oil FE testing I have seen has shown differences between oils of maybe 1-2% or occasionally slightly more. Here we are talking about a difference of much more than that and one that I am personally skeptical of for that reason.
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"Also, as I've said before, any oil FE testing I have seen has shown differences between oils of maybe 1-2% or occasionally slightly more. Here we are talking about a difference of much more than that and one that I am personally skeptical of for that reason."
What's in the FE testing. What temp condition and is this stop and go mixed with freeway driving?
What's in the FE testing. What temp condition and is this stop and go mixed with freeway driving?
Originally Posted By: glennc
TeeDub said:
The oil is being continually sheared as it's pumped throughout the engine - particularly in the main bearings. The more viscous the oil, the more energy it takes to shear it, which reduces fuel efficiency. Think of how much energy is needed to stir a glass of honey vs. one of water and you can see why this makes sense.
For an oil of a given HT/HS viscosity, the VI comes into play as it gives you some idea of how easy the oil is to pump during the warmup phase. Friction modification does help to a small degree in the valve train (particularly with flat tappets and camshaft chains.) Ring/cylinder friction normally takes place under hydrodynamic or full flow conditions, so viscosity comes into play there as well.
The main motivation in going from 5w30 to 5w-20 as the industry standard was the reduction in HT/HS viscosity from 3.0-3.2 Cp to 2.7-2.9 Cp for most of these commonly available lubricants. This is where the bulk of the fuel savings comes from....
For an oil of a given HT/HS viscosity, the VI comes into play as it gives you some idea of how easy the oil is to pump during the warmup phase. Friction modification does help to a small degree in the valve train (particularly with flat tappets and camshaft chains.) Ring/cylinder friction normally takes place under hydrodynamic or full flow conditions, so viscosity comes into play there as well.
The main motivation in going from 5w30 to 5w-20 as the industry standard was the reduction in HT/HS viscosity from 3.0-3.2 Cp to 2.7-2.9 Cp for most of these commonly available lubricants. This is where the bulk of the fuel savings comes from....
Originally Posted By: TeeDub
The oil is being continually sheared as it's pumped throughout the engine - particularly in the main bearings. The more viscous the oil, the more energy it takes to shear it, which reduces fuel efficiency.
Then it is viscosity (kinematic) and not HTHS that you are referring to. I would agree with that being the most important factor for efficiency, by far. Next AFAIK would be friction modification. Friction modification by itself can make a difference of a couple of percent, and I know of no other factor (aside from basic pumping viscosity) that is in that range.
Originally Posted By: TeeDub
Friction modification does help to a small degree in the valve train (particularly with flat tappets and camshaft chains.) Ring/cylinder friction normally takes place under hydrodynamic or full flow conditions, so viscosity comes into play there as well.
Viscosity is in play everywhere, is it not? The importance of HTHS is simply that when the oil's viscosity breaks down under stress, it fails to provide the resistance to motion that would otherwise be expected, with implications for both its protective ability and friction characteristics.
Originally Posted By: TeeDub
The main motivation in going from 5w30 to 5w-20 as the industry
standard was the reduction in HT/HS viscosity from 3.0-3.2 Cp to 2.7-2.9 Cp for most of these commonly available lubricants. This is where the bulk of the fuel savings comes from....
I'm afraid I disagree completely. The main motivation for going with a 5W-20 oil is that its lower viscosity (resistance to flow) offers less friction to begin with. Of course a lower HTHS does tend to go along with that.
Do you have any quantitative data that shows the relationship of HTHS and FE?
The oil is being continually sheared as it's pumped throughout the engine - particularly in the main bearings. The more viscous the oil, the more energy it takes to shear it, which reduces fuel efficiency.
Then it is viscosity (kinematic) and not HTHS that you are referring to. I would agree with that being the most important factor for efficiency, by far. Next AFAIK would be friction modification. Friction modification by itself can make a difference of a couple of percent, and I know of no other factor (aside from basic pumping viscosity) that is in that range.
Originally Posted By: TeeDub
Friction modification does help to a small degree in the valve train (particularly with flat tappets and camshaft chains.) Ring/cylinder friction normally takes place under hydrodynamic or full flow conditions, so viscosity comes into play there as well.
Viscosity is in play everywhere, is it not? The importance of HTHS is simply that when the oil's viscosity breaks down under stress, it fails to provide the resistance to motion that would otherwise be expected, with implications for both its protective ability and friction characteristics.
Originally Posted By: TeeDub
The main motivation in going from 5w30 to 5w-20 as the industry
standard was the reduction in HT/HS viscosity from 3.0-3.2 Cp to 2.7-2.9 Cp for most of these commonly available lubricants. This is where the bulk of the fuel savings comes from....
I'm afraid I disagree completely. The main motivation for going with a 5W-20 oil is that its lower viscosity (resistance to flow) offers less friction to begin with. Of course a lower HTHS does tend to go along with that.
Do you have any quantitative data that shows the relationship of HTHS and FE?
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There is internal friction in any oil, as it it churned/sheared around by whatever internal engine parts.
Then there is the friction of metal to metal that is attenuated by the oil.
Amsoil seems to be a sure winner in any lubrication category, but that tremendous increase would be jumped all over by manufacturers tomorrow if only 1/2 of it could be counted on.
Then there is the friction of metal to metal that is attenuated by the oil.
Amsoil seems to be a sure winner in any lubrication category, but that tremendous increase would be jumped all over by manufacturers tomorrow if only 1/2 of it could be counted on.
Buster, I have to ask you the same question as I've asked TeeDub. I've seen many references to a correlation between HTHS and FE, and I believe that there is one. Blenders often try to reduce HTHS while maintaining performance in order to improve FE. However I have seen no quantitative data to show the degree of correlation. Are you aware of any such data?
There is plenty of data to show that friction modification can be responsible for differences of 1-2% and sometimes more.
Of course, viscosity is the largest variable of all. But base stock may be important too:
Roy Howell states that "Red Line has 1/2 Cf of Mobil 1" in this old and very interesting little piece, posted here at times in the past:
http://www.getahelmet.com/jeeps/tech/redline-chemist/
There is plenty of data to show that friction modification can be responsible for differences of 1-2% and sometimes more.
Of course, viscosity is the largest variable of all. But base stock may be important too:
Roy Howell states that "Red Line has 1/2 Cf of Mobil 1" in this old and very interesting little piece, posted here at times in the past:
http://www.getahelmet.com/jeeps/tech/redline-chemist/
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Originally Posted By: glennc
Roy Howell states that "Red Line has 1/2 Cf of Mobil 1" in this old and very interesting little piece, posted here at times in the past:
http://www.getahelmet.com/jeeps/tech/redline-chemist/
But half of very small is very small. Todays oils are different than all the myths and old ideas and thoughts about oil.
Roy Howell states that "Red Line has 1/2 Cf of Mobil 1" in this old and very interesting little piece, posted here at times in the past:
http://www.getahelmet.com/jeeps/tech/redline-chemist/
But half of very small is very small. Todays oils are different than all the myths and old ideas and thoughts about oil.
Glenn,
Here's a comparison to consider....
Take the following three oils - all use a PAO/Ester base stock and the same additive chemistry - with the exception of the # of VI modifier:
SAE Grade--------Vis @ 100C---------HT/HS vis @ 150C---"Shearing Ratio"
15w-40------------14.4 Cst------------4.4 Cp----------3.27
0w-40-------------14.4 Cst------------3.6 Cp----------4.00
10w-30------------11.7 Cst------------3.6 Cp----------3.25
Now run these three oils in a turbocharged, 1.8L VW engine on a stand @ 3000 rpms, with the oil sump temp stabilized @ 100C....
Questions:
1) Which of these formulations will give you the highest initial fuel efficiency and which will give you the lowest?
2) Same question as #1, but after 100 hours of operation
If you understand the correct answers to these questions, you'll understand the relationship between HT/HS viscosity and fuel efficiency....
Here's a comparison to consider....
Take the following three oils - all use a PAO/Ester base stock and the same additive chemistry - with the exception of the # of VI modifier:
SAE Grade--------Vis @ 100C---------HT/HS vis @ 150C---"Shearing Ratio"
15w-40------------14.4 Cst------------4.4 Cp----------3.27
0w-40-------------14.4 Cst------------3.6 Cp----------4.00
10w-30------------11.7 Cst------------3.6 Cp----------3.25
Now run these three oils in a turbocharged, 1.8L VW engine on a stand @ 3000 rpms, with the oil sump temp stabilized @ 100C....
Questions:
1) Which of these formulations will give you the highest initial fuel efficiency and which will give you the lowest?
2) Same question as #1, but after 100 hours of operation
If you understand the correct answers to these questions, you'll understand the relationship between HT/HS viscosity and fuel efficiency....
I don't mean to sound insulting but I am getting the impression that you are implying a level of understanding in this that you don't actually have. The reason I say this is that you are posting some rather confusing comparisons - for example, you are calling the ratio between viscosity and HTHS the "shearing ratio," and then asking a question about how the oil will perform after 100 hours. The shear implied by the ratio between viscosity and HTHS is "temporary shear," while the shear implied by 100 hours of running is "permanent shear." They are not the same thing. Truly, an oil that exhibits a high degree of temporary shear might also be prone to a higher degree of permanent shear, but it also might not. It depends on not just the quantity of VII in the oil but also the quality and the types of VII used. Some are much more resistant to permanent shear than others. More to the point, what happens to the oil after 100 hours only confuses the basic question by introducing unrelated variables.
Next, to know whether the 15w40 or the 0W-40 oil would have better FE implies a knowledge of how much the difference in HTHS will impact the FE. That's actually the question I'm asking you to explain your understanding of, but instead you pose this comparison, which is effectively a completely circular exercise, saying in essence, "if you understand the answer to this question, then you will know the answer to this question." Well, obviously.
If you do know the answer then tell me, how would the 15w40 and 0W-40 compare in FE? That will tell us the importance of HTHS to FE in this one instance. And how does the 0W-40 compare to the 10w30 in FE? That will tell us the importance of kinematic viscosity in this one instance. Forget about after 100 hours, because that does nothing but alter variables that are irrelevant to the question in the first place.
Next, to know whether the 15w40 or the 0W-40 oil would have better FE implies a knowledge of how much the difference in HTHS will impact the FE. That's actually the question I'm asking you to explain your understanding of, but instead you pose this comparison, which is effectively a completely circular exercise, saying in essence, "if you understand the answer to this question, then you will know the answer to this question." Well, obviously.
If you do know the answer then tell me, how would the 15w40 and 0W-40 compare in FE? That will tell us the importance of HTHS to FE in this one instance. And how does the 0W-40 compare to the 10w30 in FE? That will tell us the importance of kinematic viscosity in this one instance. Forget about after 100 hours, because that does nothing but alter variables that are irrelevant to the question in the first place.
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Glenn,
That "shear ratio" IS the best predictor of how much the oil will shear in service, as it does correlate to the # of VI improver (how compressible the oil is). If you look at the details of the ASTM D-4683, HT/HS test, you it's easy to see why this rule of thumb works. There is no such thing as a shear stable VI improver although some are better than others.
The 0w-40 will provide a fuel savings of 2%-3% in comparison to the 15w40 initially - after 100 hours in a turbo the 0w-40 will shear down by 10%-15% and so the difference will be even greater. It's tough to quantify it, but basically every 10% increase or decrease in the HT/HS viscosity yields a delta in FE of approx +/- 2% - provided the rest of the formulation chemistry is the same.
As for the 10w30, 0w-40 comparison, I'd expect them to do about the same initially in terms of FE. Again however that 10w30 is going to be much more shear stable, so the 0w-40 will show higher FE after 100 hrs of operation.
The reason I chose these comparative viscosities is to illustrate that the Vis @ 100C is a very poor predictor of performance in service, as the oil is tested under a low shear rate in an unconstrained condition. Anywhere the oil is actually doing something, whether it's in the oil pump, the main bearings, the ring/cylinder interface, or between the cam lobes/lifters, it's being sheared at a high rate, with localized heating effects. That's why the HT/HS (tapered bearing simulator) test is a much better figure of merit in terms of fuel efficiency.
Of course the best way to convince yourself is simply to run your own controlled experiment. I've tested everything from SAE 0w-20 to 20w-50 and these relationships do seem to hold.
That "shear ratio" IS the best predictor of how much the oil will shear in service, as it does correlate to the # of VI improver (how compressible the oil is). If you look at the details of the ASTM D-4683, HT/HS test, you it's easy to see why this rule of thumb works. There is no such thing as a shear stable VI improver although some are better than others.
The 0w-40 will provide a fuel savings of 2%-3% in comparison to the 15w40 initially - after 100 hours in a turbo the 0w-40 will shear down by 10%-15% and so the difference will be even greater. It's tough to quantify it, but basically every 10% increase or decrease in the HT/HS viscosity yields a delta in FE of approx +/- 2% - provided the rest of the formulation chemistry is the same.
As for the 10w30, 0w-40 comparison, I'd expect them to do about the same initially in terms of FE. Again however that 10w30 is going to be much more shear stable, so the 0w-40 will show higher FE after 100 hrs of operation.
The reason I chose these comparative viscosities is to illustrate that the Vis @ 100C is a very poor predictor of performance in service, as the oil is tested under a low shear rate in an unconstrained condition. Anywhere the oil is actually doing something, whether it's in the oil pump, the main bearings, the ring/cylinder interface, or between the cam lobes/lifters, it's being sheared at a high rate, with localized heating effects. That's why the HT/HS (tapered bearing simulator) test is a much better figure of merit in terms of fuel efficiency.
Of course the best way to convince yourself is simply to run your own controlled experiment. I've tested everything from SAE 0w-20 to 20w-50 and these relationships do seem to hold.
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