To add, metallurgy is pretty important for parts that are in boundry lubrication (ie, cams and followers, rings, etc), and plays a large role in wear control. We've seen instances were no matter how good the oil's AF/AW package, if the metallurgy is wrong/bad, wear will still occur. A better oil may slow it down some, but you can't fix bad metallurgy or design defects with oil.
Pennzoil Claims Formulation of Platinum Changed to Reflect New 15,000-mile Guarantee On Bottle
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I remember, (I believe it was one of your threads with HPL?), that someone had mentioned that the viscosity improvers, additive package, etc. played into the MOFT equation. I don't remember the details exactly, but it was more than just thick vs thin.
My only point is I don't think we hang a digital banner on the home page of BITOG saying "only buy 30 weight and above."
I appreciate your posts @ZeeOSix
The level and kind of VIs can effect the HTHS viscosity based on how those additives behave at high shear rates, but MOFT is still directly connected to viscosity when the other factors influencing MOFT are held constant (ie, clearances, speed, load, etc). Higher HTHS viscosity will always result in more MOFT due to the basic physics of Tribology.
But the "film strength" of the oil (ie, the AF/AW additives) that provide the sacrificial tribofilm on parts is important when parts are rubbing in mixed and boundary lubrication, or when hydrodynamic lubrication MOFT goes to zero. Like mentioned above, parts that live primarily in mixed and boundary lubrication realms are designed to have very hard surfaces, like cams, followers, rings, etc. Journal bearings are pretty soft compared to other components, and are themselves somewhat sacrificial through wear to a point when MOFT goes to zero. The more you can keep journal bearings in full hydrodynamic lubrication and other components in mixed lubrication a bit more separated with more MOFT, the better. That's where the MOFT headroom comes in.
Yes, the engine's use condictions are definately a consideration, as well has how well the oil temperature is maintained under use. Toyota OMs even mention to use a higher viscosity if the vehicle is used harder. Vehicles not pushed very hard can live well on xW-20, but IMO anything pushed more than just normal driving around would be better protected with a xW-30, and of course if the car is raced you'd be better with a xW-40 or xW-50. I recall a guy on YT saying he ran a 5W-20 on his tracked car because he though it would keep the oil temps down, but he ended up causing some pretty good wear on the journal bearings instead.
This Machinery Lubrication article is good and explains the difference between film thickness and film strength. Film thickness (the MOFT) is always the main wear mitigation, and the film strength (the AF/AW tribofilm) kicks in to mitatgate wear when the film thickness can't maintain itself and parts are rubbing in mixed and boundary lubrication.
The Importance of Lubricant Film Strength
Discover why film strength is one of the most critical lubricant properties for protecting a machine’s internal components.
www.machinerylubrication.com
"Film strength can be described as the lubricant’s ability to lessen the effects of friction and control wear by means other than the film thickness. As mentioned, the viscosity is the primary contributor to film thickness during hydrodynamic and elastohydrodynamic lubrication. When the base oil viscosity is insufficient to overcome metal-to-metal surface contact, the base oil and additive chemistry work together to create a surface protection mechanism. During these boundary conditions, boundary lubrication is also influenced by the chemical and physical properties of the mechanical surfaces and any contributing environmental factors."
Exceptionally well explained, thank you!The level and kind of VIs can effect the HTHS viscosity based on how those additives behave at high shear rates, but MOFT is still directly connected to viscosity when the other factors influencing MOFT are held constant (ie, clearances, speed, load, etc). Higher HTHS viscosity will always result in more MOFT due to the basic physics of Tribology.
But the "film strength" of the oil (ie, the AF/AW additives) that provide the sacrificial tribofilm on parts is important when parts are rubbing in mixed and boundary lubrication, or when hydrodynamic lubrication MOFT goes to zero. Like mentioned above, parts that live primarily in mixed and boundary lubrication realms are designed to have very hard surfaces, like cams, followers, rings, etc. Journal bearings are pretty soft compared to other components, and are themselves somewhat sacrificial through wear to a point when MOFT goes to zero. The more you can keep journal bearings in full hydrodynamic lubrication and other components in mixed lubrication a bit more separated with more MOFT, the better. That's where the MOFT headroom comes in.
Yes, the engine's use condictions are definately a consideration, as well has how well the oil temperature is maintained under use. Toyota OMs even mention to use a higher viscosity if the vehicle is used harder. Vehicles not pushed very hard can live well on xW-20, but IMO anything pushed more than just normal driving around would be better protected with a xW-30, and of course if the car is raced you'd be better with a xW-40 or xW-50. I recall a guy on YT saying he ran a 5W-20 on his tracked car because he though it would keep the oil temps down, but he ended up causing some pretty good wear on the journal bearings instead.
This Machinery Lubrication article is good and explains the difference between film thickness and film strength. Film thickness (the MOFT) is always the main wear mitigation, and the film strength (the AF/AW tribofilm) kicks in to mitatgate wear when the film thickness can't maintain itself and parts are rubbing in mixed and boundary lubrication.
The Importance of Lubricant Film Strength
Discover why film strength is one of the most critical lubricant properties for protecting a machine’s internal components.
"Film strength can be described as the lubricant’s ability to lessen the effects of friction and control wear by means other than the film thickness. As mentioned, the viscosity is the primary contributor to film thickness during hydrodynamic and elastohydrodynamic lubrication. When the base oil viscosity is insufficient to overcome metal-to-metal surface contact, the base oil and additive chemistry work together to create a surface protection mechanism. During these boundary conditions, boundary lubrication is also influenced by the chemical and physical properties of the mechanical surfaces and any contributing environmental factors."
Thanks!!!!The level and kind of VIs can effect the HTHS viscosity based on how those additives behave at high shear rates, but MOFT is still directly connected to viscosity when the other factors influencing MOFT are held constant (ie, clearances, speed, load, etc). Higher HTHS viscosity will always result in more MOFT due to the basic physics of Tribology.
But the "film strength" of the oil (ie, the AF/AW additives) that provide the sacrificial tribofilm on parts is important when parts are rubbing in mixed and boundary lubrication, or when hydrodynamic lubrication MOFT goes to zero. Like mentioned above, parts that live primarily in mixed and boundary lubrication realms are designed to have very hard surfaces, like cams, followers, rings, etc. Journal bearings are pretty soft compared to other components, and are themselves somewhat sacrificial through wear to a point when MOFT goes to zero. The more you can keep journal bearings in full hydrodynamic lubrication and other components in mixed lubrication a bit more separated with more MOFT, the better. That's where the MOFT headroom comes in.
Yes, the engine's use condictions are definately a consideration, as well has how well the oil temperature is maintained under use. Toyota OMs even mention to use a higher viscosity if the vehicle is used harder. Vehicles not pushed very hard can live well on xW-20, but IMO anything pushed more than just normal driving around would be better protected with a xW-30, and of course if the car is raced you'd be better with a xW-40 or xW-50. I recall a guy on YT saying he ran a 5W-20 on his tracked car because he though it would keep the oil temps down, but he ended up causing some pretty good wear on the journal bearings instead.
This Machinery Lubrication article is good and explains the difference between film thickness and film strength. Film thickness (the MOFT) is always the main wear mitigation, and the film strength (the AF/AW tribofilm) kicks in to mitatgate wear when the film thickness can't maintain itself and parts are rubbing in mixed and boundary lubrication.
The Importance of Lubricant Film Strength
Discover why film strength is one of the most critical lubricant properties for protecting a machine’s internal components.
"Film strength can be described as the lubricant’s ability to lessen the effects of friction and control wear by means other than the film thickness. As mentioned, the viscosity is the primary contributor to film thickness during hydrodynamic and elastohydrodynamic lubrication. When the base oil viscosity is insufficient to overcome metal-to-metal surface contact, the base oil and additive chemistry work together to create a surface protection mechanism. During these boundary conditions, boundary lubrication is also influenced by the chemical and physical properties of the mechanical surfaces and any contributing environmental factors."
Honestly, this should be pinned at the top. Seriously.
Agree!
Zee took Extra Strength Smart Pills yesterday…
Which means he was even smarter than he normally is… Which is quite impressive because on a regular day he is really intelligent. This is a genuine observation and compliment Zee.
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They did
Yeah no doubt… Good call there man.
What if your life depended on it? Would you feel comfortable in a Bradley or Abrams running thin oil in the crankcase to save a few bucks on fuel, or would you rather arrive home in one piece?
4WD
$50 site donor 2024
Abrams are turbine powered and don’t use Walmart 1
Not sure if this was posted before but regarding what that 15,000 mile oil service life means, this is what is on the Pennzoil web site:
1 Lubrication Limited Warranty. Protection for up to 15,000 miles or one year, whichever comes first. Use an oil filter designed for longer oil change intervals and follow OEM manual and vehicle’s oil life sensor to maintain OEM warranty. Excludes severe driving conditions, including racing and commercial use. Your engine must have fewer than 125,000 miles and have been manufactured in the past 72 months. Enrollment required. Other conditions apply. See pennzoil.com/warranty to enroll and for full details and terms.
Also, regarding HTHS - you can have it measured as like any other oil test.
Ali
1 Lubrication Limited Warranty. Protection for up to 15,000 miles or one year, whichever comes first. Use an oil filter designed for longer oil change intervals and follow OEM manual and vehicle’s oil life sensor to maintain OEM warranty. Excludes severe driving conditions, including racing and commercial use. Your engine must have fewer than 125,000 miles and have been manufactured in the past 72 months. Enrollment required. Other conditions apply. See pennzoil.com/warranty to enroll and for full details and terms.
Also, regarding HTHS - you can have it measured as like any other oil test.
Ali
Well that was random.
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