demarpaint
Thread starter
Originally Posted By: dave1251
Originally Posted By: friendly_jacek
Originally Posted By: modularv8
Oils that are too thick or out of spec for an engine design/OEM recommendation can and do increase the wear rate, particularly the piston ring pack. From all the SAE papers on this subject, an HTHS of 2.6 cP to 2.8 cP is the ideal range for maximum fuel economy and engine durability. Nothing is ever compromised and there are added benefits to low viscosity lubricants.
Can you produce any literature to show increased wear over HTHS 2.8 please? I would like to learn something new (for a change).
Also, can you explain why Toyota allows up to 20W50 in Europe and Australia in their cars?
Thanks!
Below are a few references that show the ideal range that compromises engine wear, fuel economy, and efficiency. HTHS 2.6-2.8 is the ideal range. Higher HTHS than 2.8 does not allow for significantly less wear while the parasitic frictional losses are significantly higher. Lower HTHS oils with less additives will be developed with out compromising engine wear because of friction reducing coating are and will be used in manufacturing.
http://www.sveacon.se/lectures/tribology.pdf
http://performanceracingoils.com/PDF/Nanotechnology_in_gear_oils.pdf
The stigma of lower viscosity oils not being able to protect from wear is because of little to no VI's were used in 20 oil grade testing about 20 years ago. Once higher grade base oils became more common along with the implementation of VI's in PCMO this negated the need for higher HTHS to prevent wear. Also oil performance was best expressed as the frequency of excessive wear, rather than by quantitative wear measurement.
Further studies by Ford R&D in particular reasoned the minimum HTHS of 2.6 was enough before engine wear was accelerated.
This was discussed before with references as you requested.
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1061666&page=1
With all the information discussed here and all the technical papers, studies, and ect. I have determined that unless there is a factor that would cause you to use your engine that would not let the oil cool off such as hours upon hours of red line, or a mechanical/design issue that would cause the oil to constantly have a HTHS less than 2.6 than I would use a higher than 20 grade to compensate. If the manufacture recommends 20 grade for you application there was more than enough testing done to justify the recommendation. If a 20 grade was not recommended there is a reason for not making that recommendation. This is the reason why I do not particularly care for what is recommended for use in other parts of the world. I do not know how a car is driven in a another part of the world and I do not know the chemical make up of a PCMO sold and readily available elsewhere some VOA's from other members in other countries outside of North America has shown that a PCMO can have a different make up and a different than predicted testing outcome.
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2446740#Post2446740
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2677642#Post2677642
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2677653#Post2677653
Also different engineers with different backgrounds and objectives will make recommendation on their parameters. I do not know if BMW's philosophy is to make a recommendation that is to minimize engine wear at all cost even if it is to compromise engine efficiency even if this means recommending a higher grade of oil that does not offer significantly higher wear protection but allows for a higher safety margin. Some people just want redundancy with redundancy there is not wrong with that.
While those studies are interesting what happens to the guy running at high speeds on the Autobahn with a 20 grade oil only to find he did permanent damage to the engine because the oil couldn't handle it?
Originally Posted By: friendly_jacek
Originally Posted By: modularv8
Oils that are too thick or out of spec for an engine design/OEM recommendation can and do increase the wear rate, particularly the piston ring pack. From all the SAE papers on this subject, an HTHS of 2.6 cP to 2.8 cP is the ideal range for maximum fuel economy and engine durability. Nothing is ever compromised and there are added benefits to low viscosity lubricants.
Can you produce any literature to show increased wear over HTHS 2.8 please? I would like to learn something new (for a change).
Also, can you explain why Toyota allows up to 20W50 in Europe and Australia in their cars?
Thanks!
Below are a few references that show the ideal range that compromises engine wear, fuel economy, and efficiency. HTHS 2.6-2.8 is the ideal range. Higher HTHS than 2.8 does not allow for significantly less wear while the parasitic frictional losses are significantly higher. Lower HTHS oils with less additives will be developed with out compromising engine wear because of friction reducing coating are and will be used in manufacturing.
http://www.sveacon.se/lectures/tribology.pdf
http://performanceracingoils.com/PDF/Nanotechnology_in_gear_oils.pdf
The stigma of lower viscosity oils not being able to protect from wear is because of little to no VI's were used in 20 oil grade testing about 20 years ago. Once higher grade base oils became more common along with the implementation of VI's in PCMO this negated the need for higher HTHS to prevent wear. Also oil performance was best expressed as the frequency of excessive wear, rather than by quantitative wear measurement.
Further studies by Ford R&D in particular reasoned the minimum HTHS of 2.6 was enough before engine wear was accelerated.
This was discussed before with references as you requested.
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1061666&page=1
With all the information discussed here and all the technical papers, studies, and ect. I have determined that unless there is a factor that would cause you to use your engine that would not let the oil cool off such as hours upon hours of red line, or a mechanical/design issue that would cause the oil to constantly have a HTHS less than 2.6 than I would use a higher than 20 grade to compensate. If the manufacture recommends 20 grade for you application there was more than enough testing done to justify the recommendation. If a 20 grade was not recommended there is a reason for not making that recommendation. This is the reason why I do not particularly care for what is recommended for use in other parts of the world. I do not know how a car is driven in a another part of the world and I do not know the chemical make up of a PCMO sold and readily available elsewhere some VOA's from other members in other countries outside of North America has shown that a PCMO can have a different make up and a different than predicted testing outcome.
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2446740#Post2446740
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2677642#Post2677642
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2677653#Post2677653
Also different engineers with different backgrounds and objectives will make recommendation on their parameters. I do not know if BMW's philosophy is to make a recommendation that is to minimize engine wear at all cost even if it is to compromise engine efficiency even if this means recommending a higher grade of oil that does not offer significantly higher wear protection but allows for a higher safety margin. Some people just want redundancy with redundancy there is not wrong with that.
While those studies are interesting what happens to the guy running at high speeds on the Autobahn with a 20 grade oil only to find he did permanent damage to the engine because the oil couldn't handle it?