Do the individual additives in manufactures add-packs depend on a certain oil temperature to work best? Years ago I read this relating to gear oils but, wondered about modern engine oils. Thank you. Ed
Add-pack additives vs Temperature
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I think they are all designed with a nominal average engine operating temperature in mind.
Yes, at least with regard to friction modifiers.
I know with ZDDP to work the oil temps must get up to at least 80C for the plating effect to occur. Once it has been activated it's effect applies at all temps.
I know with ZDDP to work the oil temps must get up to at least 80C for the plating effect to occur. Once it has been activated it's effect applies at all temps.
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Originally Posted By: CATERHAM
Yes, at least with regard to friction modifiers.
I know with ZDDP to work the oil temps must get up to at least 80C for the plating effect to occur. Once it has been activated it's effect applies at all temps.
As long as the sacrificial boundary layer isn't sacrificed. Anything that sees boundary lubrication as a given will see increased wear until that process is re-enabled. At least that's how I understand it.
Yes, at least with regard to friction modifiers.
I know with ZDDP to work the oil temps must get up to at least 80C for the plating effect to occur. Once it has been activated it's effect applies at all temps.
As long as the sacrificial boundary layer isn't sacrificed. Anything that sees boundary lubrication as a given will see increased wear until that process is re-enabled. At least that's how I understand it.
That's my understanding as well, but you must periodically get the oil up to temperature for the plating effect to occur.
I had a long discussion once with Dave at RL and others on the negative effects of not getting the oil hot at least now and then, even if condensation is not an issue and you're running a light 20wt oil. It's a problem with one of my cars that has a heavily finned alloy sump.
Then there is the issue of other competing fm's such as moly and polar esters. I've been told how they all fit into the equation but it's rather fuzzy. But I do remember the bottom line, get the oil up to at least 80C every time you run the engine before you shut it down, if you can.
I had a long discussion once with Dave at RL and others on the negative effects of not getting the oil hot at least now and then, even if condensation is not an issue and you're running a light 20wt oil. It's a problem with one of my cars that has a heavily finned alloy sump.
Then there is the issue of other competing fm's such as moly and polar esters. I've been told how they all fit into the equation but it's rather fuzzy. But I do remember the bottom line, get the oil up to at least 80C every time you run the engine before you shut it down, if you can.
Originally Posted By: CATERHAM
I had a long discussion once with Dave at RL and others on the negative effects of not getting the oil hot at least now and then, even if condensation is not an issue and you're running a light 20wt oil. It's a problem with one of my cars that has a heavily finned alloy sump.
That's a good point that I think often gets missed. Of course, we think of temperature to get rid of condensation and provide optimal flow and lubrication. We all consider what viscosity to choose based upon what temperatures the oil faces, both ambient and operating, and the oil pressure. It's nice to be reminded once and a while that there are other reasons to get the oil up to operating temperature.
I had a long discussion once with Dave at RL and others on the negative effects of not getting the oil hot at least now and then, even if condensation is not an issue and you're running a light 20wt oil. It's a problem with one of my cars that has a heavily finned alloy sump.
That's a good point that I think often gets missed. Of course, we think of temperature to get rid of condensation and provide optimal flow and lubrication. We all consider what viscosity to choose based upon what temperatures the oil faces, both ambient and operating, and the oil pressure. It's nice to be reminded once and a while that there are other reasons to get the oil up to operating temperature.
Originally Posted By: CATERHAM
That's my understanding as well, but you must periodically get the oil up to temperature for the plating effect to occur.
These additives work better at temps but the localized temp. in the contact zone will get WAY above 80C, and will be activated by that heat. Pressure (from contact) also increases the hardness/thickness of the zinc tribo films.
That's my understanding as well, but you must periodically get the oil up to temperature for the plating effect to occur.
These additives work better at temps but the localized temp. in the contact zone will get WAY above 80C, and will be activated by that heat. Pressure (from contact) also increases the hardness/thickness of the zinc tribo films.
Good information. Thank you. Ed
Different types of dispersants and detergents are often included for different temperatures ranges.
Originally Posted By: Tempest
Originally Posted By: CATERHAM
That's my understanding as well, but you must periodically get the oil up to temperature for the plating effect to occur.
These additives work better at temps but the localized temp. in the contact zone will get WAY above 80C, and will be activated by that heat. Pressure (from contact) also increases the hardness/thickness of the zinc tribo films.
Thank you for the education. Short-trippers need not worry about extra wear in winter. Oil may be trashed but bearings will still be in good shape.
Originally Posted By: CATERHAM
That's my understanding as well, but you must periodically get the oil up to temperature for the plating effect to occur.
These additives work better at temps but the localized temp. in the contact zone will get WAY above 80C, and will be activated by that heat. Pressure (from contact) also increases the hardness/thickness of the zinc tribo films.
Thank you for the education. Short-trippers need not worry about extra wear in winter. Oil may be trashed but bearings will still be in good shape.
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The start up wear curve is mostly unavoidable. It will typically have the same length. I would imagine the amount of unavoidable wear would vary slightly depending on starting temp. The time to fully warmed will be about the same, but that number will be different. Meanwhile the temp where stuff reacts won't change.
The start up wear curve may be unavoidable but it certainly can be mitigated since it plays such a significant part in total engine wear.
Hybrid engines undoubtedly exacerbate the problem with their frequent start/stop cycling and low operating oil temps.
Hence the development by the Japanese OEM's of the new 0W-20 grade, ultra low viscosity, high VI oils with special additives such as high levels of organic moly.
Hybrid engines undoubtedly exacerbate the problem with their frequent start/stop cycling and low operating oil temps.
Hence the development by the Japanese OEM's of the new 0W-20 grade, ultra low viscosity, high VI oils with special additives such as high levels of organic moly.
i beleive dry starts are more harmful than anything. you said hybrid engines exacerbate the problem (because they switch on and off constantly) if all the parts are already soaked in warm oil, starting it up isnt going to harm it.
You may be right once the oil is up to temperature but it may cycle on and off many times before that happens vs a non hybrid application where it starts once per trip. Furthemore, when the engine's supplimental power is demanded, close to instant maximum torque often applies.
Not surprisingly, to offset these less than ideal conditions, these new OEM oils from Toyota and Honda have the lowest start- up viscosities available in a PCMO.
Not surprisingly, to offset these less than ideal conditions, these new OEM oils from Toyota and Honda have the lowest start- up viscosities available in a PCMO.
you make an excellent point with it not actually getting up to temp, and requiring max power, or close to it, once started, i think the thin oil in that case was a good idea. however since it is a toyota, it will still last many thousands of miles.
the new Dodge Challenger has an oil pan heater option
i was thinking that maybe toyota thought of that and put one in the prius
Toyota did think of something similar. When the Prius engine is turned off, it pumps the coolant into a thermos that keeps it warm for 2-3 days. Perfect for overnight. No external hookup is required. I wish I had this cool feature in my Civic Hybrid.
pumps coolant into a thermos...gotta link or anything on this? im curious now.
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