Engine Heat and the Additive Pack

[Shel_B]

It's been written here that some engine oil additives (in the formulated ad-pack) are activated by heat. Which additives need heat to work properly, to their designed capacity, and how much heat is needed? Would short tripping activate these additives? Thanks!

 

[Jetronic]

ZDDP needs heat, but too much can make it shoot it's wad premature aswell. But pretty much all chemical processes work faster with more heat.

edit: see what could happen if oil gets too hot:

 

[Bill_W]

In general EP/anti wear additives are heat activated.

 

[weasley]

As said above, ZDDP needs heat and pressure to start working. It is generally accepted that 60°C or so is the wake-up point.

As also stated, all chemical reactions increase rate with temperature. Sometimes this works for you (eg surface bonding, acid neutralisation etc) and sometimes against you (oxidation, degradation).

 

[Graham Piccinini]

It's been written here that some engine oil additives (in the formulated ad-pack) are activated by heat. Which additives need heat to work properly, to their designed capacity, and how much heat is needed? Would short tripping activate these additives? Thanks!

Interesting that you mention this, as a similar topic has been "grinding my gears" a little here and there lately.
- Highway driving is widely considered the easiest usage for the oil, with the least amount of wear for the engine. Yet...
- ...Oil temps are the highest on the highway. One would think that high oil temps destroy the oil in constant use... Shear and stuff...
- Is it fair to say that constant heat, and lack of cooldown/heat-up cycles (such as what short-tripped vehicles experience) is what keeps the engine wear to a minimum and lets the oil stay in "healthy" state for longer periods? Is it the lack of moisture and oxidation that keeps the ad packs from depleting too quickly?

 

[robertcope]

My oil temps are never the highest on the highway. Always the coolest, in fact.

 

[kschachn]

My oil temps are never the highest on the highway. Always the coolest, in fact.

It should be the steady-state design temperature, right? Assuming no mechanical defects.

 

[SammyChevelleTypeS3]

Some oil companies claim that "our oil works 10x or 20x better to protect your engine from heat." How can one company make that claim when others do not? All in the mixing process and different additives? What is in this additive pack that can accomplish such a thing?

 

[kschachn]

Some oil companies claim that "our oil works 10x or 20x better to protect your engine from heat." How can one company make that claim when others do not? All in the mixing process and different additives? What is in this additive pack that can accomplish such a thing?

10x or 20x or 100x is quite irrelevant unless an absolute comparison to a standard is given. One of the first things you learn in statistics.

Such unitless comparisons are not untrue but at the same time they are functionally useless.

 

[High Performance Lubricants]

Don’t confuse sump temperatures with the oil’s ability to work at the lubrication point. I have been on the Dyno with engines that were iced before making a pull and evaluating oils where I know where the heat activation point is. The oil responded as it should as there is plenty of heat at the lubrication point for the additives to be activated. This is all with a sump temperature of under 100F.

 

[Graham Piccinini]

My oil temps are never the highest on the highway. Always the coolest, in fact.

Stole this from another thread, but this poster confirms higher temps on the highway:
https://bobistheoilguy.com/forums/t...ewd-no-gas-price-pics-etc.356182/post-6365810

 

[SammyChevelleTypeS3]

Don’t confuse sump temperatures with the oil’s ability to work at the lubrication point. I have been on the Dyno with engines that were iced before making a pull and evaluating oils where I know where the heat activation point is. The oil responded as it should as there is plenty of heat at the lubrication point for the additives to be activated. This is all with a sump temperature of under 100F.

Got it. thank u

 

[robertcope]

It should be the steady-state design temperature, right? Assuming no mechanical defects.

That's not how it works on any car I've ever owned. Drive them on the highway, not making much power just moving down the road or spinning much RPM, they run cool. Get them on track, or just drive them hard or high RPM, temps go up. Not really rocket science. Or maybe it is.

 

[robertcope]

Stole this from another thread, but this poster confirms higher temps on the highway:
https://bobistheoilguy.com/forums/t...ewd-no-gas-price-pics-etc.356182/post-6365810

Well, I can't argue with that. Wait, I can. For my cars, the highway is where they run the coolest. I can easily heat things up getting them on track or just running them hard on the street. This doesn't seem like a crazy concept. Pushing a car down the highway at low RPM/low power output makes less heat than accelerating with high RPMs.

 

[kschachn]

That's not how it works on any car I've ever owned. Drive them on the highway, not making much power just moving down the road or spinning much RPM, they run cool. Get them on track, or just drive them hard or high RPM, temps go up. Not really rocket science. Or maybe it is.

You’re staying that moving down the highway at a relatively constant speed the oil temperature isn’t at the design point?

 

[medunko]

Cannot understand - highway and coolest temp?
I’m driving constantly 4 or 5 hours at highway - 4500 rpm and 100 mph and the oil temp should be cool?

 

[ZeeOSix]

Stole this from another thread, but this poster confirms higher temps on the highway:
https://bobistheoilguy.com/forums/t...ewd-no-gas-price-pics-etc.356182/post-6365810

No oil cooler, probably a contributing factor. Any car with an oil cooler will have lower oil temp just cruising down the road at pretty low RPM in high gear with active oil cooling going on.

 

[ZeeOSix]

Cannot understand - highway and coolest temp?
I’m driving constantly 4 or 5 hours at highway - 4500 rpm and 100 mph and the oil temp should be cool?

Obviously if you're "cruising" at 4500 RPM at 100 MPH the oil is going to heat up more than cruising at 60 MPH at 1800 RPM.

 

[PimTac]

Cannot understand - highway and coolest temp?
I’m driving constantly 4 or 5 hours at highway - 4500 rpm and 100 mph and the oil temp should be cool?

You are the exception. Choose to drive like that and you get what’s coming.

 

[medunko]

So obviously depends by car. Small engine bigger Revs at highway.
Driving like (fast) -100mph at highway that is not forbidden in some countries in Europe.