I've heard of oils that claim to have low HTHS viscosity for fuel economy, but still protect extremely well. How exactly does that work? Does it mean the oil makes a really thin but really strong film? What is it about an oil that can make it good at preventing metal-to-metal contact without also making it thick? I do understand vaguely that viscosity doesn't necessarily equal protection, but I don't know much about the chemistry involved.
HTHS question (high vs. low)
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I guess that means no 5W-20 for you
. In my 2002 F-150 4.6 V-8 I use the spec'd 5W-20 oil. It's a manual tranny but I don't push it. It sits outside in the winter and with the Motorcraft 5W-20 and Motorcraft FL820S oil filter it starts in the real cold temps without a wimper or other "unholy" sounds 
. My garaged 2L 4 cyl. Zetec 1996 Contour was eventually back spec'd for 5W-20 from 5W-30. However I'm still using Schaeffers Supreme Blend 5W-30 with it's relatively higher HTHS, because it's my "poor mans" "BMW" and I drive it "enthusiastically" to say the least
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With my truck I need every mpg and the cold start advantage I can get. With my Contour I can use a "thicker" oil because it's winter garaged and driven harder, but in the warmer temps.
Basically you have to decide what's best for your driving style and enviroment.
Whimsey
. My garaged 2L 4 cyl. Zetec 1996 Contour was eventually back spec'd for 5W-20 from 5W-30. However I'm still using Schaeffers Supreme Blend 5W-30 with it's relatively higher HTHS, because it's my "poor mans" "BMW" and I drive it "enthusiastically" to say the least
With my truck I need every mpg and the cold start advantage I can get. With my Contour I can use a "thicker" oil because it's winter garaged and driven harder, but in the warmer temps.
Basically you have to decide what's best for your driving style and enviroment.
Whimsey
Remember, where the oil film fails to protect additives come into play. If the engine's designed to run on lower than average HTHS values, than I see no reason not to...the thing is most vehicle manuals fail to give a specific spec.
The only trouble I know of where additives can't play much of a role where a lubricating oil film is breached, is with plain bearing designs - as the bearing material is softer than the plated/reactive anti-wear material, and thus is not able to support the loads imposed if force density is high, as well as chemical reactivity with these structural metals.
That's what I have come to here/read thus far, but there's likely more angles to be had, just like there's no one answer for the numerous potential conditions to encounter each time the engine is started and one heads out to get things done.
Take care.
The only trouble I know of where additives can't play much of a role where a lubricating oil film is breached, is with plain bearing designs - as the bearing material is softer than the plated/reactive anti-wear material, and thus is not able to support the loads imposed if force density is high, as well as chemical reactivity with these structural metals.
That's what I have come to here/read thus far, but there's likely more angles to be had, just like there's no one answer for the numerous potential conditions to encounter each time the engine is started and one heads out to get things done.
Take care.
Even if the viscosity is low ie 0w-20 you still want the highest HTHS you can get. You sacrifice high HTHS when you select the lower viscosities and improve it when you select the higher viscosities. This is the reason I run a 0w-40 oil with a HTHS over 3.5. Excellent results on wear for me so far.
I just did some reading. Let me make sure I understand: an oil with a low HTHS value would have poor hydrodynamic lubrication properties because it would be pressed or sheared out from between two surfaces easily. However, it could still have excellent barrier lubrication properties with the correct formulation. Therefore, assuming the oil's barrier lubrication properties are sufficient for the engine and usage patterns, the only potential problem with a low HTHS would be that kinematic viscosity would also be low, which would make it harder for the pump to maintain proper pressure at high temperatures.
Does that sound about right?
Does that sound about right?
Under higher temperature (leads to viscosity thinning), and high levels of shear (high forces that work to bring the two lubricated bodies together...force oil out from between these two bodies), oils with lower test values maintain a lower film thickness. Now for what dictates the lowest "acceptable" value for this one test property of an oil, would be the height of asperities on both moving surfaces relatively speaking, and any foreign matter that finds its way through via lubricant stream. At least that is how I understand it.
The question is amongst all such points of shear in an engine/machine under normal-full load, what's likely to present the harshest conditions that would dictate a given HTHS value for the sake of reasonable longevity/service while still preserving a measurable means of economy? There's various levels of pressure, load distribution, surface finish, temperature...
Interesting.
The question is amongst all such points of shear in an engine/machine under normal-full load, what's likely to present the harshest conditions that would dictate a given HTHS value for the sake of reasonable longevity/service while still preserving a measurable means of economy? There's various levels of pressure, load distribution, surface finish, temperature...
Interesting.
Just a thought...more oil that bleeds out from zones of lubrication need be replaces, and thus would present greater oil flow rates in general...or that should be the case anyway. That being so, I would think that yes, oil pressures would likely be "lower" with an oil of lower HTHS value verses like operating conditions with an oil of higher HTHS. However, not all regions of the engine would be running so high a stress level and I can't say that all oil's share a defined viscosity value on approach to the HTHS values as defines by such test parameters. Would such pressure differences really be all that noticeable within the error of an oil pressure gauge? Wear patterns might be more indicative, however that being what one wishes to avoid in the first place???
Cyanocobalamin contains cyanide. Even in very small amounts cyanide is known to be fatal to humans. Yet a compound that is vital to our existence contains cyanide. That substance is vitamin B12. Without it we would not be able to exist. Therefore we must look at the total picture, not just the parts.
Plain oil that has a HTHS of 3.2 was shown by itself to be able to minimize bearing wear in test engines. SA certified oils from many decades ago met that criteria. Todays SM oils contain many additives that make plain oil far superior. Fully formulated 20 grade oils of today have been shown to outperform older oils in even more demanding test conditions. Oils with a HTHS in the range of 2.5 off the shelf have been used now for long enough to show their capabilities in all sorts of applications.
In medicine we used to cut peoples wrists and bleed them to get out the “bad” humors. We no longer do this. We used to use toxic wound cleansers as peroxide or Betadine on open wounds. We no longer use them for this purpose (at least most of us no longer do so).
We need to stop clinging to older, outdated information. We need to move ahead and accept progress. It is human nature to hang on to older yet inferior things. We cannot help it.
When used in the appropriate (and expanding) applications I believe that 20 grade oil usage is taking over.
aehaas
Plain oil that has a HTHS of 3.2 was shown by itself to be able to minimize bearing wear in test engines. SA certified oils from many decades ago met that criteria. Todays SM oils contain many additives that make plain oil far superior. Fully formulated 20 grade oils of today have been shown to outperform older oils in even more demanding test conditions. Oils with a HTHS in the range of 2.5 off the shelf have been used now for long enough to show their capabilities in all sorts of applications.
In medicine we used to cut peoples wrists and bleed them to get out the “bad” humors. We no longer do this. We used to use toxic wound cleansers as peroxide or Betadine on open wounds. We no longer use them for this purpose (at least most of us no longer do so).
We need to stop clinging to older, outdated information. We need to move ahead and accept progress. It is human nature to hang on to older yet inferior things. We cannot help it.
When used in the appropriate (and expanding) applications I believe that 20 grade oil usage is taking over.
aehaas
Originally Posted By: AEHaas
Cyanocobalamin contains cyanide. Even in very small amounts cyanide is known to be fatal to humans. Yet a compound that is vital to our existence contains cyanide. That substance is vitamin B12. Without it we would not be able to exist. Therefore we must look at the total picture, not just the parts...
Off topic: I could be wrong, but cyanocobalamin itself is not vital to our existence. It is one form of vitamin B12, and B12 is vital. Cyanocobalamin is a form commonly used in supplements because it is cheap to synthesize. There are better forms of B12 out there, both in nature and supplements.
Cyanocobalamin contains cyanide. Even in very small amounts cyanide is known to be fatal to humans. Yet a compound that is vital to our existence contains cyanide. That substance is vitamin B12. Without it we would not be able to exist. Therefore we must look at the total picture, not just the parts...
Off topic: I could be wrong, but cyanocobalamin itself is not vital to our existence. It is one form of vitamin B12, and B12 is vital. Cyanocobalamin is a form commonly used in supplements because it is cheap to synthesize. There are better forms of B12 out there, both in nature and supplements.
Hi,
aehaas - your comment "Oils with a HTHS in the range of 2.5 off the shelf have been used now for long enough to show their capabilities in all sorts of applications." may be misleading!
Some applications WILL NOT tolerate a such a low HTHS viscosity!
Regards
aehaas - your comment "Oils with a HTHS in the range of 2.5 off the shelf have been used now for long enough to show their capabilities in all sorts of applications." may be misleading!
Some applications WILL NOT tolerate a such a low HTHS viscosity!
Regards
From another thread:
"This sounds like what has been going on on the Subaru boards. Quite a few people are modifying their cars, and using energy conserving xW30's. Then they go to the drag strip (or drive hard on the highway) and wonder why they've spun a bearing"
Jason Heffner, of Heffner Performance here in Sarasota is world famous for his twin turbo modifications on performance cars as the Dodge Viper, Ford GT and the Lamborghini lineup amoungst others. Jobs run in the 50 to 60,000 dollar range if not more. He has his own Dyno set up.
Even though he is doubling the BHP he is most often using the same oil grade. His cars have been used on the track racing. Check out the Feb. 2008 C&D, I think, 0-200-0 MPH article. He has been on the cover of other magazines as well.
People are always blaming the part failures on the oil. Jason replaces the bearing linings, cams, drive shafts and others parts to withstand the forces involved. Yet he usually does not change the oil grade. His cars do not blow up. Quite the contrary his cars are in demand as they last and they win.
People who do not know what they are doing blame the oil. People as Jason never worry about the oil, only the parts. He states that he only goes up a grade on occasion if turbo use causes the oil to run much hotter. And even then he only goes up one grade. This is not for around town applications but rather intense racing.
AND:
"Motorcraft/Ford indicate that a 5w50 is supposed to be used in the GT. "
Jason stated that he preferred the 15W50 in the Ford GT for hot weather but would allow for a 10W40 in cool weather. Mind you this recommendation is in his modified engines with twice the stock BHP.
He did not indicate that he ever specified a 60 grade oil for any car.
He did state that cam failures are a result of improper hardening or oil starvation and not oil viscosity.
aehaas
"This sounds like what has been going on on the Subaru boards. Quite a few people are modifying their cars, and using energy conserving xW30's. Then they go to the drag strip (or drive hard on the highway) and wonder why they've spun a bearing"
Jason Heffner, of Heffner Performance here in Sarasota is world famous for his twin turbo modifications on performance cars as the Dodge Viper, Ford GT and the Lamborghini lineup amoungst others. Jobs run in the 50 to 60,000 dollar range if not more. He has his own Dyno set up.
Even though he is doubling the BHP he is most often using the same oil grade. His cars have been used on the track racing. Check out the Feb. 2008 C&D, I think, 0-200-0 MPH article. He has been on the cover of other magazines as well.
People are always blaming the part failures on the oil. Jason replaces the bearing linings, cams, drive shafts and others parts to withstand the forces involved. Yet he usually does not change the oil grade. His cars do not blow up. Quite the contrary his cars are in demand as they last and they win.
People who do not know what they are doing blame the oil. People as Jason never worry about the oil, only the parts. He states that he only goes up a grade on occasion if turbo use causes the oil to run much hotter. And even then he only goes up one grade. This is not for around town applications but rather intense racing.
AND:
"Motorcraft/Ford indicate that a 5w50 is supposed to be used in the GT. "
Jason stated that he preferred the 15W50 in the Ford GT for hot weather but would allow for a 10W40 in cool weather. Mind you this recommendation is in his modified engines with twice the stock BHP.
He did not indicate that he ever specified a 60 grade oil for any car.
He did state that cam failures are a result of improper hardening or oil starvation and not oil viscosity.
aehaas
Originally Posted By: AEHaas
From another thread:
"This sounds like what has been going on on the Subaru boards. Quite a few people are modifying their cars, and using energy conserving xW30's. Then they go to the drag strip (or drive hard on the highway) and wonder why they've spun a bearing"
Jason Heffner, of Heffner Performance here in Sarasota is world famous for his twin turbo modifications on performance cars as the Dodge Viper, Ford GT and the Lamborghini lineup amoungst others. Jobs run in the 50 to 60,000 dollar range if not more. He has his own Dyno set up.
Even though he is doubling the BHP he is most often using the same oil grade. His cars have been used on the track racing. Check out the Feb. 2008 C&D, I think, 0-200-0 MPH article. He has been on the cover of other magazines as well.
People are always blaming the part failures on the oil. Jason replaces the bearing linings, cams, drive shafts and others parts to withstand the forces involved. Yet he usually does not change the oil grade. His cars do not blow up. Quite the contrary his cars are in demand as they last and they win.
People who do not know what they are doing blame the oil. People as Jason never worry about the oil, only the parts. He states that he only goes up a grade on occasion if turbo use causes the oil to run much hotter. And even then he only goes up one grade. This is not for around town applications but rather intense racing.
AND:
"Motorcraft/Ford indicate that a 5w50 is supposed to be used in the GT. "
Jason stated that he preferred the 15W50 in the Ford GT for hot weather but would allow for a 10W40 in cool weather. Mind you this recommendation is in his modified engines with twice the stock BHP.
He did not indicate that he ever specified a 60 grade oil for any car.
He did state that cam failures are a result of improper hardening or oil starvation and not oil viscosity.
aehaas
Most of the cars you mentioned come from the factory with a thick oil. You stated that "he preferred the 15W50 in the Ford Gt for hot weather". Is this not thicker than the factory recommended 5W50? Wow, you can get away with a slightly thinner oil in cold temps. Big deal, it doesn't prove anything. Please show me all these "twice the stock BHP" GTs running around.
It's great to have your own theories but I will stick with what has worked for me since I have torn down my own motors and don't have to rely on other's opinions. I'm sure the thin stuff has worked in your high performance cars in the sense that they haven't blown up yet but how do you know how they're wearing? A 600hp V12 is loading the rod bearings the same as a 300hp V6 all else being equal. Doesn't seem that impressive anymore.
From another thread:
"This sounds like what has been going on on the Subaru boards. Quite a few people are modifying their cars, and using energy conserving xW30's. Then they go to the drag strip (or drive hard on the highway) and wonder why they've spun a bearing"
Jason Heffner, of Heffner Performance here in Sarasota is world famous for his twin turbo modifications on performance cars as the Dodge Viper, Ford GT and the Lamborghini lineup amoungst others. Jobs run in the 50 to 60,000 dollar range if not more. He has his own Dyno set up.
Even though he is doubling the BHP he is most often using the same oil grade. His cars have been used on the track racing. Check out the Feb. 2008 C&D, I think, 0-200-0 MPH article. He has been on the cover of other magazines as well.
People are always blaming the part failures on the oil. Jason replaces the bearing linings, cams, drive shafts and others parts to withstand the forces involved. Yet he usually does not change the oil grade. His cars do not blow up. Quite the contrary his cars are in demand as they last and they win.
People who do not know what they are doing blame the oil. People as Jason never worry about the oil, only the parts. He states that he only goes up a grade on occasion if turbo use causes the oil to run much hotter. And even then he only goes up one grade. This is not for around town applications but rather intense racing.
AND:
"Motorcraft/Ford indicate that a 5w50 is supposed to be used in the GT. "
Jason stated that he preferred the 15W50 in the Ford GT for hot weather but would allow for a 10W40 in cool weather. Mind you this recommendation is in his modified engines with twice the stock BHP.
He did not indicate that he ever specified a 60 grade oil for any car.
He did state that cam failures are a result of improper hardening or oil starvation and not oil viscosity.
aehaas
Most of the cars you mentioned come from the factory with a thick oil. You stated that "he preferred the 15W50 in the Ford Gt for hot weather". Is this not thicker than the factory recommended 5W50? Wow, you can get away with a slightly thinner oil in cold temps. Big deal, it doesn't prove anything. Please show me all these "twice the stock BHP" GTs running around.
It's great to have your own theories but I will stick with what has worked for me since I have torn down my own motors and don't have to rely on other's opinions. I'm sure the thin stuff has worked in your high performance cars in the sense that they haven't blown up yet but how do you know how they're wearing? A 600hp V12 is loading the rod bearings the same as a 300hp V6 all else being equal. Doesn't seem that impressive anymore.
Originally Posted By: AEHaas
When used in the appropriate (and expanding) applications I believe that 20 grade oil usage is taking over.
aehaas
Can you elaborate on these "appropriate (and expanding) applications"? I would like to know what you consider these to be. Thank you.
When used in the appropriate (and expanding) applications I believe that 20 grade oil usage is taking over.
aehaas
Can you elaborate on these "appropriate (and expanding) applications"? I would like to know what you consider these to be. Thank you.
Originally Posted By: Curious Kid
Now for what dictates the lowest "acceptable" value for this one test property of an oil, would be the height of asperities on both moving surfaces relatively speaking, and any foreign matter that finds its way through via lubricant stream.
Aha. I had forgotten about surface asperities. Thanks.
But then, how common are asperities big enough to matter enough that a reasonable drop in HTHS (e.g. 3.5 to 2.5) would permit metal-to-metal contact?
Originally Posted By: Curious Kid
That being so, I would think that yes, oil pressures would likely be "lower" with an oil of lower HTHS value verses like operating conditions with an oil of higher HTHS. However, not all regions of the engine would be running so high a stress level and I can't say that all oil's share a defined viscosity value on approach to the HTHS values as defines by such test parameters. Would such pressure differences really be all that noticeable within the error of an oil pressure gauge?
Good point.
I was assuming that if one oil had a HTHS value lower than another, it is probably true that the former oil has a lower kinematic viscosity as well. I obviously hadn't thought it through, because I know better than that...
Now for what dictates the lowest "acceptable" value for this one test property of an oil, would be the height of asperities on both moving surfaces relatively speaking, and any foreign matter that finds its way through via lubricant stream.
Aha. I had forgotten about surface asperities. Thanks.
But then, how common are asperities big enough to matter enough that a reasonable drop in HTHS (e.g. 3.5 to 2.5) would permit metal-to-metal contact?
Originally Posted By: Curious Kid
That being so, I would think that yes, oil pressures would likely be "lower" with an oil of lower HTHS value verses like operating conditions with an oil of higher HTHS. However, not all regions of the engine would be running so high a stress level and I can't say that all oil's share a defined viscosity value on approach to the HTHS values as defines by such test parameters. Would such pressure differences really be all that noticeable within the error of an oil pressure gauge?
Good point.
I was assuming that if one oil had a HTHS value lower than another, it is probably true that the former oil has a lower kinematic viscosity as well. I obviously hadn't thought it through, because I know better than that...
Originally Posted By: BuickGN
I'm sure the thin stuff has worked in your high performance cars in the sense that they haven't blown up yet but how do you know how they're wearing?
Lots of oil analysis. Look up some of his posts in the UOA section...
I'm sure the thin stuff has worked in your high performance cars in the sense that they haven't blown up yet but how do you know how they're wearing?
Lots of oil analysis. Look up some of his posts in the UOA section...
I don't give a flying monkey about the fuel mileage savings of a lower HTHS. Such fuel mileage savings are negligible. So why bother?
What I heard was in the context of using something like Fuchs Titan GT1 0w-20 in an app that specced a 30wt or 40wt. I can't imagine that wouldn't produce a significant MPG gain, given that some people have measured MPG differences between GC and a thinner 30wt...
Originally Posted By: AEHaas
From another thread:
"This sounds like what has been going on on the Subaru boards. Quite a few people are modifying their cars, and using energy conserving xW30's. Then they go to the drag strip (or drive hard on the highway) and wonder why they've spun a bearing"
Jason Heffner, of Heffner Performance here in Sarasota is world famous for his twin turbo modifications on performance cars as the Dodge Viper, Ford GT and the Lamborghini lineup amoungst others. Jobs run in the 50 to 60,000 dollar range if not more. He has his own Dyno set up. ...
People are always blaming the part failures on the oil. ...
People who do not know what they are doing blame the oil. ...
aehaas
I didn't only blame the oil, although a lot of people are. More of my quote from the other thread:
Quote:
Cooling, det and state of tune probably comes into play in those cases as well. Subaru allows xW40's and xW50's under severe conditions, although 5W30 is on the oil cap and that's what a lot of people follow.
Does Jason Heffner run his oil for 4-5,000 miles? I think I'm more impressed seeing real world results from modified turbo Subaru's running thin oil.
A Subaru tech has posted that he's seen spun bearings from 5W30 in a conservatively driven stock WRX. Hey, maybe you should get the new STI that comes out soon and do some testing of your own!
Although, the failures are more common on the early WRX's. Unfortunately, the people that had problems didn't do a UOA and most claimed failure at or before 1k miles with 3,000 mile OCI's.
Wouldn't an oil with a higher HTHS provide a better cushion and reduce the risk of bearing issues? Or even a better oil (more AW additives like RLI, RL) than the typical Energy Conserving oil?
-Dennis
From another thread:
"This sounds like what has been going on on the Subaru boards. Quite a few people are modifying their cars, and using energy conserving xW30's. Then they go to the drag strip (or drive hard on the highway) and wonder why they've spun a bearing"
Jason Heffner, of Heffner Performance here in Sarasota is world famous for his twin turbo modifications on performance cars as the Dodge Viper, Ford GT and the Lamborghini lineup amoungst others. Jobs run in the 50 to 60,000 dollar range if not more. He has his own Dyno set up. ...
People are always blaming the part failures on the oil. ...
People who do not know what they are doing blame the oil. ...
aehaas
I didn't only blame the oil, although a lot of people are. More of my quote from the other thread:
Quote:
Cooling, det and state of tune probably comes into play in those cases as well. Subaru allows xW40's and xW50's under severe conditions, although 5W30 is on the oil cap and that's what a lot of people follow.
Does Jason Heffner run his oil for 4-5,000 miles? I think I'm more impressed seeing real world results from modified turbo Subaru's running thin oil.
A Subaru tech has posted that he's seen spun bearings from 5W30 in a conservatively driven stock WRX. Hey, maybe you should get the new STI that comes out soon and do some testing of your own!
Wouldn't an oil with a higher HTHS provide a better cushion and reduce the risk of bearing issues? Or even a better oil (more AW additives like RLI, RL) than the typical Energy Conserving oil?
-Dennis
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