passenger car fuel economy

[Jetronic]

passenger car fuel economy improvement through FM or vis

graphite and MoS2 are mentioned and both score extremely well. Maybe ther might be something about the claims of MoS2 users?

I noticed graphite and MoS2 were mentioned in the article Shannow posted today

 

[4wheeldog]

That study is from 1978. I would like to believe that oils have improved in many ways, in the last 38 years.

 

[Garak]

Or, at the very least, they haven't let those friction modifiers just sit in limbo.

 

[Jetronic]

Originally Posted By: 4wheeldog
That study is from 1978. I would like to believe that oils have improved in many ways, in the last 38 years.




the oils did change, but a glass phosphate coating still is that, with the accompanying friction coefficient.

 

[GaleHawkins]

Oils have improved and I have never got a boost in MPG from any additive that math could support.

I do think tire air pressure and the type tires one runs can be a much greater factor in passenger car fuel economy for example.

 

[Jetronic]

driving style is an even bigger factor...

but in 1978 the math worked out to about 5% savings for the solid colloidal suspensions...

 

[SuperSalad]

STLE had an article published two or three years ago in their TLT magazine that mentioned big savings just from going to lower winter ratings. If I remember correctly, the tester saw a 5%-10% improvement by going to a 0W-30 over a 10W-30. Sorry I don't have a link to it right now, I'll try to track it down if I can.

 

[Jetronic]

the link above said about 1% per grade...

10w-40 to 10w-30 equals 1% saving, 10w-30 to 5w-30 another percent. I think due to more VII and less hths

Now, if you drive with a mostly cold engine, savings could be higher

 

[kschachn]

Originally Posted By: MotoTribologist
STLE had an article published two or three years ago in their TLT magazine that mentioned big savings just from going to lower winter ratings. If I remember correctly, the tester saw a 5%-10% improvement by going to a 0W-30 over a 10W-30. Sorry I don't have a link to it right now, I'll try to track it down if I can.


I would love to see any article that claims a 5-10% fuel economy increase between a 10W-30 and a 0W-30 oil.

 

[SuperSalad]

Originally Posted By: kschachn
Originally Posted By: MotoTribologist
STLE had an article published two or three years ago in their TLT magazine that mentioned big savings just from going to lower winter ratings. If I remember correctly, the tester saw a 5%-10% improvement by going to a 0W-30 over a 10W-30. Sorry I don't have a link to it right now, I'll try to track it down if I can.


I would love to see any article that claims a 5-10% fuel economy increase between a 10W-30 and a 0W-30 oil.

Found it!

http://digital.ipcprintservices.com/publication/?p=8&i=154798&ver=swf&pp=1&zoom=0

It was actually 10% on one vehicle and 13% on a second and going from 5W-30 and 5W-20. Granted this isn't the most controlled experiment and it is an editorial, but I've been reading this guy's editorials for years now and I trust it.

I switched from 5W-30 to 0W-30 in my own car and got 4.5%. Better driving habits bumped me up to 18%. I went from 22 to 26 mpg averaged over 10 tanks of pure commuting the same route every day. I didn't take congestion into account but still; I'm a believer now.

 

[hatt]

Originally Posted By: MotoTribologist
Originally Posted By: kschachn
Originally Posted By: MotoTribologist
STLE had an article published two or three years ago in their TLT magazine that mentioned big savings just from going to lower winter ratings. If I remember correctly, the tester saw a 5%-10% improvement by going to a 0W-30 over a 10W-30. Sorry I don't have a link to it right now, I'll try to track it down if I can.


I would love to see any article that claims a 5-10% fuel economy increase between a 10W-30 and a 0W-30 oil.

Found it!

http://digital.ipcprintservices.com/publication/?p=8&i=154798&ver=swf&pp=1&zoom=0

It was actually 10% on one vehicle and 13% on a second and going from 5W-30 and 5W-20. Granted this isn't the most controlled experiment and it is an editorial, but I've been reading this guy's editorials for years now and I trust it.

I switched from 5W-30 to 0W-30 in my own car and got 4.5%. Better driving habits bumped me up to 18%. I went from 22 to 26 mpg averaged over 10 tanks of pure commuting the same route every day. I didn't take congestion into account but still; I'm a believer now.
How were you able to conclude the oil accounted for 4.5% of 18%? Were the driving conditions 1 mile trips twice a day in -30F? Was your prior driving style fulls gas pedal to move and full brake to stop? So many questions.

 

[SuperSalad]

Originally Posted By: hatt
How were you able to conclude the oil accounted for 4.5% of 18%? Were the driving conditions 1 mile trips twice a day in -30F? Was your prior driving style fulls gas pedal to move and full brake to stop? So many questions.


Because I went from 22 to 23 miles per gallon when I changed from 5W-30 to 0W-30. Then when I changed my driving to a pseudo hypermiling style it went up to 26 mpg. So 4.5% gain from changing grades and then about 18% total with the grade and driving style combined from the original 22 mpg. I'm not saying it is incredibly scientific, just my own experience.

Beforehand I did not pay much attention to it and just drove in a reactionary style. Then I changed my habits to plan as far as I could see down the road and employed some hypermiling habits. I drive fairly reliably 50 miles per day round trip to work so I eliminated certain weeks that had large mile differences from my data and did the math over a few months.

 

[GaleHawkins]

Thanks for the link.

 

[Pontual]

1% graphite makes 3 to 5% FEI!


Bring ARCO GRAPHITE BACK!


I knew there was something behind that...

Thanks for the link, op

 

[kschachn]

Originally Posted By: MotoTribologist
Found it!

http://digital.ipcprintservices.com/publication/?p=8&i=154798&ver=swf&pp=1&zoom=0

It was actually 10% on one vehicle and 13% on a second and going from 5W-30 and 5W-20. Granted this isn't the most controlled experiment and it is an editorial, but I've been reading this guy's editorials for years now and I trust it.

I switched from 5W-30 to 0W-30 in my own car and got 4.5%. Better driving habits bumped me up to 18%. I went from 22 to 26 mpg averaged over 10 tanks of pure commuting the same route every day. I didn't take congestion into account but still; I'm a believer now.


Unfortunately that article is less than worthless, it makes claims that are not supported by any means. How did the author measure his fuel economy? It (almost) cannot be done in the real world, numerous articles are available that describe the near impossibility of making any comparisons such as this in the real world. For one thing the energy density of gasoline varies even at the same gas station 4% to 5%, and without using standardized test fuel any comparison that does not take this into account is meaningless. Add into the mix all the other environmental factors such as temperature, wind velocity, terrain, driving conditions (traffic, etc.), any results on a comparison basis are meaningless. There is no way any such ad hoc test could isolate any observed difference and attribute it to the oil.

Plus the whole conclusion is ridiculous. If in fact there really was a 10% to 13% increase in fuel economy, why wouldn't ExxonMobil claim this for AFE instead of the puny claims they do make?

Without controlled laboratory tests his claim is absurd and to me would make suspect anything else that magazine publishes. You just don't do this kind of testing in real world, there are too many variables.

 

[SuperSalad]

Originally Posted By: kschachn
Originally Posted By: MotoTribologist
Found it!

http://digital.ipcprintservices.com/publication/?p=8&i=154798&ver=swf&pp=1&zoom=0

It was actually 10% on one vehicle and 13% on a second and going from 5W-30 and 5W-20. Granted this isn't the most controlled experiment and it is an editorial, but I've been reading this guy's editorials for years now and I trust it.

I switched from 5W-30 to 0W-30 in my own car and got 4.5%. Better driving habits bumped me up to 18%. I went from 22 to 26 mpg averaged over 10 tanks of pure commuting the same route every day. I didn't take congestion into account but still; I'm a believer now.


Unfortunately that article is less than worthless, it makes claims that are not supported by any means. How did the author measure his fuel economy? It (almost) cannot be done in the real world, numerous articles are available that describe the near impossibility of making any comparisons such as this in the real world. For one thing the energy density of gasoline varies even at the same gas station 4% to 5%, and without using standardized test fuel any comparison that does not take this into account is meaningless. Add into the mix all the other environmental factors such as temperature, wind velocity, terrain, driving conditions (traffic, etc.), any results on a comparison basis are meaningless. There is no way any such ad hoc test could isolate any observed difference and attribute it to the oil.

Plus the whole conclusion is ridiculous. If in fact there really was a 10% to 13% increase in fuel economy, why wouldn't ExxonMobil claim this for AFE instead of the puny claims they do make?

Without controlled laboratory tests his claim is absurd and to me would make suspect anything else that magazine publishes. You just don't do this kind of testing in real world, there are too many variables.


Ok, take a deep breath and chill out for a second. Then remember the fact that it is an editorial and not a scientific paper subject to peer review. It was an interesting anecdote he shared with his readers and that's it.

That being said; he measured his fuel economy before and after. He changed his oil and his fuel economy went up. I then made a similar change, and my fuel economy increased. So, it was not worthless to me. The article was just a reference point to help describe my anecdote of increased fuel economy from switching to a lower winter grade.

I would guess ExxonMobil wouldn't make those claims because then they would be beholden to them. That is why they claim up to 2% to stay within liability constraints. Just my theory on that though, maybe there is more to it.

 

[kschachn]

Yes, I have a huge problem with someone in a Tribology & Lubrication Technology publication authoring trash. But maybe that's just me.

And also maybe it's just my years as a research technologist for a company that is the problem too. When you want to measure something, anything, you devise a test where all known variables are held constant except for the one you wish to measure. This guy did none of that. I'll stand by my statement that the article worthless, the editors of that publication should never have let such an article be published. It should make anything else they publish suspect.

And in the example you gave from your own experience, there's no way you could measure a 1 MPG increase and attribute it to the single variable of motor oil. Not with all the other variables present in real-world driving. 1 MPG improvement from 22 to 23 MPG is a 4.5% change, well within even the error bar of just the gasoline energy density itself - not to mention all the other variables in real world driving.

There are all sorts of articles available that give detail about how fiendishly difficult it is to measure real-world fuel economy and how even with controls in place it still is very hard to get repeatable and accurate numbers. Just changing your oil and driving for a few weeks or months is not going to do it.

Originally Posted By: MotoTribologist
Ok, take a deep breath and chill out for a second. Then remember the fact that it is an editorial and not a scientific paper subject to peer review. It was an interesting anecdote he shared with his readers and that's it.

That being said; he measured his fuel economy before and after. He changed his oil and his fuel economy went up. I then made a similar change, and my fuel economy increased. So, it was not worthless to me. The article was just a reference point to help describe my anecdote of increased fuel economy from switching to a lower winter grade.

I would guess ExxonMobil wouldn't make those claims because then they would be beholden to them. That is why they claim up to 2% to stay within liability constraints. Just my theory on that though, maybe there is more to it.

 

[SuperSalad]

Originally Posted By: kschachn
Yes, I have a huge problem with someone in a Tribology & Lubrication Technology publication authoring trash. But maybe that's just me.

And also maybe it's just my years as a research technologist for a company that is the problem too. When you want to measure something, anything, you devise a test where all known variables are held constant except for the one you wish to measure. This guy did none of that. I'll stand by my statement that the article worthless, the editors of that publication should never have let such an article be published. It should make anything else they publish suspect.

And in the example you gave from your own experience, there's no way you could measure a 1 MPG increase and attribute it to the single variable of motor oil. Not with all the other variables present in real-world driving. 1 MPG improvement from 22 to 23 MPG is a 4.5% change, well within even the error bar of just the gasoline energy density itself - not to mention all the other variables in real world driving.

There are all sorts of articles available that give detail about how fiendishly difficult it is to measure real-world fuel economy and how even with controls in place it still is very hard to get repeatable and accurate numbers. Just changing your oil and driving for a few weeks or months is not going to do it.

Originally Posted By: MotoTribologist
Ok, take a deep breath and chill out for a second. Then remember the fact that it is an editorial and not a scientific paper subject to peer review. It was an interesting anecdote he shared with his readers and that's it.

That being said; he measured his fuel economy before and after. He changed his oil and his fuel economy went up. I then made a similar change, and my fuel economy increased. So, it was not worthless to me. The article was just a reference point to help describe my anecdote of increased fuel economy from switching to a lower winter grade.

I would guess ExxonMobil wouldn't make those claims because then they would be beholden to them. That is why they claim up to 2% to stay within liability constraints. Just my theory on that though, maybe there is more to it.


No one claimed that this was a well controlled and documented test. It was his editorial column that I related to my own anecdote. I said that my experiences weren't well controlled, but I still saw the results I hoped for. Maybe it is a placebo effect, but regardless, I now get better gas mileage than I did before.

If you don't want to take what limited value it offers, that is fine, however it sounds like you are trying to disclaim the entire idea because an anecdote does not meet a level of standardization that it never even pretended to meet in the first place.

 

[kschachn]

Originally Posted By: MotoTribologist
No one claimed that this was a well controlled and documented test. It was his editorial column that I related to my own anecdote. I said that my experiences weren't well controlled, but I still saw the results I hoped for. Maybe it is a placebo effect, but regardless, I now get better gas mileage than I did before.

If you don't want to take what limited value it offers, that is fine, however it sounds like you are trying to disclaim the entire idea because an anecdote does not meet a level of standardization that it never even pretended to meet in the first place.


Well OK, if all you are trying to do is support your already formed opinion then yes, that is a good article. But if you are expecting an accurate article coming from what appears to be a respectable trade publication then it falls very short.

You also have to realize that his numbers are outliers, there is no one else claiming anything near that kind of result. No one.

 

[circuitsmith]

Look at it in terms of energy.
A reduction in friction amounting to 4% of the engine's input would significantly lower the oil temperature.
If it's cruising along at 20HP out that's ~60HP of heat coming from the fuel.
4% of that = 2.4HP = 1.8KW heat generated in the oil due to viscosity.
So, what's the data on oil temp vs viscosity?