5w-40 Beginning TBNs

[m37charlie]

Find a Mobil distributor and ask. Where do you live? I have purchased relatively retail quantities the 2 times I bought it.
But the SHC isn’t good for a US mfg engine; new stuff “Ultimate Defense” is ok((CI4+ etc)

 

[53' Stude]

Find a Mobil distributor and ask. Where do you live? I have purchased relatively retail quantities the 2 times I bought it.
But the SHC isn’t good for a US mfg engine; new stuff “Ultimate Defense” is ok((CI4+ etc)

It would work fine in a R Model Mack

 

[Fishstyx]

According to Lake Speed Jr. TBN is an outdated data point and isn’t needed anymore. Because of the ultra low sulfur diesel fuel does not create a high acid reaction to the base as it used to do in high sulfur diesel fuel. I would be concerned about oxidation.

 

[burbguy82]

Hey fellow oil enthusiasts,
I'm trying to compare beginning TBN numbers on 5w-40 synthetic diesel oils. I'm having trouble finding the specs. This is what I have versus what I don't...

T6 9.84
Mobil DELVAC 12.?
Valvoline Blue line
NAPA HD
Chevron DELO XSP

I ask to make sure I get the best protection since I do a lot of short trips and a fair amount of idling. I do pay attention to the trucks oil life monitor. The truck is a '17 Ram 1500 w/3.0L Ecodiesel.

Thanks for all input and recommendations in advance.

I run 5w40 Napa, I did a VOA years ago, and it was 11.

 

[Fishstyx]

Here’s another reason why TBN is moot. https://www.chevronlubricants.com/c...YSIS UNDERSTANDING TAN AND TBN 01-28-2019.pdf

 

[burbguy82]

Here’s another reason why TBN is moot. https://www.chevronlubricants.com/content/dam/external/industrial/en_us/sales-material/sales-sheet/ENGINE OIL ANALYSIS UNDERSTANDING TAN AND TBN 01-28-2019.pdf

maybe for a diesel, but especially not moot for a newer DI engine

 

[kschachn]

maybe for a diesel, but especially not moot for a newer DI engine

Why is that?

 

[burbguy82]

Why is that?

Is TBN not a measure of reserve alkalinity? The higher the TBN the longer the oil will neutralize acids? Or is that BS too?

 

[kschachn]

Is TBN not a measure of reserve alkalinity? The higher the TBN the longer the oil will neutralize acids? Or is that BS too?

Yes it's a buffer. But I was asking in relation to a DI engine, I don't know what the connection is.

 

[burbguy82]

Yes it's a buffer. But I was asking in relation to a DI engine, I don't know what the connection is.

Would you agree that the injector pressure must be higher than cylinder pressure in order to inject directly into the cylinder?

 

[kschachn]

Would you agree that the injector pressure must be higher than cylinder pressure in order to inject directly into the cylinder?

What? I don't get it.

What is the connection to the TBN? It's an honest question, I don't understand.

 

[burbguy82]

@kschachn

If injector pressure must be higher than cylinder pressure in order to inject, (which it has to be) then fuel, and combustion gases MUST be allowed past the rings. What is under the rings? The oil sump. So, TBN measures an oils ability to neutralize acidity..........the higher the TBN, the better the "buffer" as you adequately put.

 

[kschachn]

Combustion chamber pressures in an GDI engine are higher after ignition?

 

[burbguy82]

Combustion chamber pressures in an GDI engine are higher after ignition?

no clue, that is not what I am saying.

If the injector inject into the cylinder, in order for that to happen, the injector must inject at a higher pressure than the cylinder is, and the only way that can happen is if this compression can get past the rings.

 

[kschachn]

no clue, that is not what I am saying.

If the injector inject into the cylinder, in order for that to happen, the injector must inject at a higher pressure than the cylinder is, and the only way that can happen is if this compression can get past the rings.

I still don't understand. Maybe it's just me.

The pressure of the injector must be higher than the cylinder pressure when injection occurs. I don't get the second part. Why does it have to "get past the rings"? And what do you mean by it happening by "this compression" getting past the rings?

The reason I asked about combustion pressure is because this blowby is what introduces water vapor and the products of combustion into the oil, which depletes the TBN depending on the sulfur content of the fuel. Unburned gasoline doesn't cause this but it does other things to the oil (especially the VM).

 

[burbguy82]

I still don't understand. Maybe it's just me.

The pressure of the injector must be higher than the cylinder pressure when injection occurs. I don't get the second part. Why does it have to "get past the rings"? And what do you mean by it happening by "this compression" getting past the rings?

The reason I asked about combustion pressure is because this blowby is what introduces water vapor and the products of combustion into the oil, which depletes the TBN depending on the sulfur content of the fuel. Unburned gasoline doesn't cause this but it does other things to the oil (especially the VM).

Assume 150 psi cylinder pressure...........the max cylinder pressure for this hypothetical...

the injector must be able to overcome the cylinder pressure, probably by a lot due to injection duty and time.......but for this hypo, we will say 5psi.....

now, being as the cylinder prsssure is 150 max, if it is injected with something higher psi, the cylinder must allow excess pressure to pass, somehow someway, or something will blow.

Simply put, if you pressurize a cylinder with more pressure than what it can make, it will leak. What leaks? A combination of gas, and air/combustion gases.

Remember it does not make any difference the pressure, if you inject something into a pressurized vessel, the required pressure must be more, to do so.

With the coking up of intake vavles of these DI engines such as some of the GM Ecotec engines, I argue that fuel is not leaking into the intake valves, lest they would be clean, and not into the exhaust, lest it backfire, so that leaves only one place, the crankcase.

That is my logic, what do you think?

 

[kschachn]

Assume 150 psi cylinder pressure...........the max cylinder pressure for this hypothetical...

the injector must be able to overcome the cylinder pressure, probably by a lot due to injection duty and time.......but for this hypo, we will say 5psi.....

now, being as the cylinder prsssure is 150 max, if it is injected with something higher psi, the cylinder must allow excess pressure to pass, somehow someway, or something will blow.

Simply put, if you pressurize a cylinder with more pressure than what it can make, it will leak. What leaks? A combination of gas, and air/combustion gases.

Remember it does not make any difference the pressure, if you inject something into a pressurized vessel, the required pressure must be more, to do so.

With the coking up of intake vavles of these DI engines such as some of the GM Ecotec engines, I argue that fuel is not leaking into the intake valves, lest they would be clean, and not into the exhaust, lest it backfire, so that leaves only one place, the crankcase.

That is my logic, what do you think?

Why does it have to pass anywhere? The fuel being injected at that point will have a minimal effect on the cylinder pressure especially when compared to the pressure increase from combustion.

You're stuck on this mysterious chamber pressure increase after injection which is not significant in relation to the rest of the cycle. And besides, that increase would only push unburnt fuel and air past the rings. It's blowby that is a result of combustion that affects the TBN of the oil. Those gasses are where acids come from. But even that is mitigated quite a bit these days by the use of low-sulfur fuel.

The rest of your post about coking and intake valves is not relevant to the notion that the TBN is reduced due to GDI. Fuel wash is something completely different if you're thinking that's how unburned gasoline gets into oil.

 

[Fishstyx]

maybe for a diesel, but especially not moot for a newer DI engine

Actually it is the TAN is more important as is the oxidation value.

 

[burbguy82]

Why does it have to pass anywhere?

If you do not understand or agree with this principle, then we will not come to an understanding. Good talk.

 

[cptbarkey]

Would you agree that the injector pressure must be higher than cylinder pressure in order to inject directly into the cylinder?

Watch an animation of how engines work, pay attention to the exhaust valves, pistons and fuel injection timing.