Detergents: Magnesium vs Calcium

[RDY4WAR]

I read recently that magnesium is twice as effective as calcium as a detergent and is better at TBN retention. How true is that statement? Also in terms of effectiveness, how does Boron play into the detergent picture?

 

[MolaKule]

Boron Additives Multi-Functional Additives

 

[StevieC]

I think it depends on the overall additive package and base oil on how well the cleaning effect is on the engine. Detergent choice is only a part of this but definitely important. The reason Calcium is being scaled back and we are seeing more of the other detergents is because of LSPI which can be affected by high amounts of Calcium in the oil's add-pack. Calcium served us quite well before then and it's why companies like Amsoil used a ton of it in their extended drain oils to keep the engine really clean for the long haul. Thanks MolaKule for the links. I had missed those.

 

[dave1251]

Originally Posted by RDY4WAR

I read recently that magnesium is twice as effective as calcium as a detergent and is better at TBN retention. How true is that statement? Also in terms of effectiveness, how does Boron play into the detergent picture?

I'm certain Mola addresses this. But to put this in my laymen terms. Boron has a mild detergent function and it is secondary consequence. It's primary fuction is a friction modifier. It is a example why we should look at all the available information of lube before we choose one reason like or recommend a product.

 

[RDY4WAR]

I've read those links. I guess I'm looking for layman's terms. I know Calcium is being scaled back over LSPI concerns. I wondering about the effectiveness. Amsoil SS being a good example. The old formula had Ca, Mg, and B totalling around 3900 ppm. The new formula with far less Ca and more Mg and B only totals around 2600 ppm. Should I understand this to mean that the new formula is only 67% as effective at cleaning as the old formula or that its equally (or more) effective with Mg and B being more effective cleaning additives? I'm not looking for a product recommendation or other uses of these additives. I'm asking strictly from a ln effectiveness of cleaning (and possibly TBN retention) standpoint. Just for knowledge sake.

 

[dave1251]

Originally Posted by RDY4WAR

I've read those links. I guess I'm looking for layman's terms. I know Calcium is being scaled back over LSPI concerns. I wondering about the effectiveness. Amsoil SS being a good example. The old formula had Ca, Mg, and B totalling around 3900 ppm. The new formula with far less Ca and more Mg and B only totals around 2600 ppm. Should I underdtand this that the new formula is only 67% as effective at cleaning as the old formula or that its equally (or more) effective with Mg and B being more effective?

Mg is very effective just as Ca the reason for its lack of broad use before is likely due to cost. The example I can find is before DEXOS 1 Gen 2 is its use was reserved to higher end synthetics such as 0W40 M-1 and M-1 EP

 

[RDY4WAR]

I understand that... You said "Mg is very effective just as Ca" so you're saying Mg is equal to Ca 1:1 ppm in cleaning ability? Ok... with Amsoil's new formula, they lowered Ca by 2000+ppm. However, they didn't increase Mg by 2000+ ppm, only about 950 ppm. Given these facts, am I to believe that only 950 ppm of Mg is equally as effective of detergency as 2000 ppm of Ca? Or does the new formula have a 33% weaker detergent package?

 

[DrDanger]

Super layman reply. It is based on info exclusively from here. Mag has a slightly higher base number. It was dirt cheap, maybe still is. Trouble is ,from what I understand, that if you have a dirty engine, or you do a longer oci, its agglomerates(cleaning agent connected to dirt) are of higher abrasiveness than calcium. Seam to remember troubles with diesels as well, but not sure.

 

[kschachn]

Originally Posted by DrDanger

Super layman reply. It is based on info exclusively from here. Mag has a slightly higher base number. It was dirt cheap, maybe still is. Trouble is ,from what I understand, that if you have a dirty engine, or you do a longer oci, its agglomerates(cleaning agent connected to dirt) are of higher abrasiveness than calcium. Seam to remember troubles with diesels as well, but not sure.

Which magnesium compounds are you referring to specifically?

 

[DrDanger]

Originally Posted by kschachn

Originally Posted by DrDanger

Super layman reply. It is based on info exclusively from here. Mag has a slightly higher base number. It was dirt cheap, maybe still is. Trouble is ,from what I understand, that if you have a dirty engine, or you do a longer oci, its agglomerates(cleaning agent connected to dirt) are of higher abrasiveness than calcium. Seam to remember troubles with diesels as well, but not sure.

Which magnesium compounds are you referring to specifically?

As a laymen, I could not say. Here are some relevant threads. SonofJoe's post are a particularly good read. https://www.bobistheoilguy.com/foru...-diesel-oil-do-more-cleaning#Post4756466 https://www.bobistheoilguy.com/foru...-levels-but-more-cleanliness#Post4752473 Plenty more threads in this forum on the topic. I'm currently using a calcium and magnesium containing oil, but dont believe there is a magnesium only oil.

 

[SonofJoe]

We've been over this ground before. The overbased metallic detergents in engine oils don't actually 'deterge' so play absolutely no role in cleaning your engine. It's true that these additives do actually contain 'detergent'. You will find stuff like Linear Alkyl Benzene Sulphonates in all sorts of industrial cleaners. However the purpose of these detergents in overbased metallic detergent additives is to maintain mineral Calcium Carbonate (simple chalk) or Magnesium Carbonate (magnesia) in a very fine colloidal suspension. Yes, impossible as it may sound, something like 300 TBN calcium sulphonate contains about 30% chalk; the same stuff you use to write on a blackboard! It's the chalk (or magnesia) that gives oil it's alkalinity and allows the oil to 'mop up' acids created by combustion or the oxidation of base oil. For me, magnesium vs calcium is something of a toss up. In my experience, at equal TBN, in gasoline engines, they are roughly equivalent. I have a personal preference for Mg but only because in overall terms, it tends to be cheaper (Mg has a lower molecular weight than Ca so less metal is required to 'carry' a given weight on sulphate ions). Regarding TBN retention, it's a daft theory pushed by daft people trying to con you into thinking that things are complicated when they basically aren't.

 

[gathermewool]

Originally Posted by SonofJoe

Regarding TBN retention, it's a daft theory pushed by daft people trying to con you into thinking that things are complicated when they basically aren't.

Nice...

 

[RDY4WAR]

DrDanger, thanks for the links. That's more of the information I'm looking for.

Originally Posted by SonofJoe

We've been over this ground before. The overbased metallic detergents in engine oils don't actually 'deterge' so play absolutely no role in cleaning your engine. It's true that these additives do actually contain 'detergent'. You will find stuff like Linear Alkyl Benzene Sulphonates in all sorts of industrial cleaners. However the purpose of these detergents in overbased metallic detergent additives is to maintain mineral Calcium Carbonate (simple chalk) or Magnesium Carbonate (magnesia) in a very fine colloidal suspension. Yes, impossible as it may sound, something like 300 TBN calcium sulphonate contains about 30% chalk; the same stuff you use to write on a blackboard! It's the chalk (or magnesia) that gives oil it's alkalinity and allows the oil to 'mop up' acids created by combustion or the oxidation of base oil. For me, magnesium vs calcium is something of a toss up. In my experience, at equal TBN, in gasoline engines, they are roughly equivalent. I have a personal preference for Mg but only because in overall terms, it tends to be cheaper (Mg has a lower molecular weight than Ca so less metal is required to 'carry' a given weight on sulphate ions). Regarding TBN retention, it's a daft theory pushed by daft people trying to con you into thinking that things are complicated when they basically aren't.

SonofJoe, I hold your posts in high regard on here. Thanks for the correction on detergency. From what you've said, Ca and Mg are about equal in their role, right? Mg just gets it done with less ash? If you were formulating an oil for older engines with high mileage and sludge/buildup, cost not being a concern, which path for "detergents" would you prefer?

 

[RDY4WAR]

This is the post I read that stated Mg is twice as effective as Ca. This was the first I'd heard this and nobody refuted it so I created this thread looking for confirmation or if the statement is a load of bull. https://bobistheoilguy.com/forums/ubbthreads.php/topics/4214347/re-detergents#Post4214347

 

[Garak]

Magnesium was helpful with diesel engine oils, too, in getting the SA down and the TBN up when formulating an E7, E9 lubricant.

 

[lukejo]

Originally Posted by RDY4WAR

This is the post I read that stated Mg is twice as effective as Ca. This was the first I'd heard this and nobody refuted it so I created this thread looking for confirmation or if the statement is a load of bull. https://bobistheoilguy.com/forums/ubbthreads.php/topics/4214347/re-detergents#Post4214347

Right—if Mg is as good or better than Ca, and according to SonofJoe above, Mg tends to be cheaper, why did companies like Amsoil stick with Ca until LSPI and Dex gen 2 came on the scene? Which makes me wonder if, as I alluded to in my recent post, if you don't need Gen 2 in your application, would one of the "old school" gen 1 oils loaded with Ca (like Shaeffer's) be a better choice than the gen 2 cert oils and newest formula from Amsoil?

 

[RDY4WAR]

Sadly we have no way of knowing how many ashless detergents/dispersants are added. If they still claim a TBN of 12.0 with more than a 30% drop in detergents, then one must assume ADs.

 

[SonofJoe]

Originally Posted by lukejo

Originally Posted by RDY4WAR

This is the post I read that stated Mg is twice as effective as Ca. This was the first I'd heard this and nobody refuted it so I created this thread looking for confirmation or if the statement is a load of bull. https://bobistheoilguy.com/forums/ubbthreads.php/topics/4214347/re-detergents#Post4214347

Right—if Mg is as good or better than Ca, and according to SonofJoe above, Mg tends to be cheaper, why did companies like Amsoil stick with Ca until LSPI and Dex gen 2 came on the scene? Which makes me wonder if, as I alluded to in my recent post, if you don't need Gen 2 in your application, would one of the "old school" gen 1 oils loaded with Ca (like Shaeffer's) be a better choice than the gen 2 cert oils and newest formula from Amsoil?

In terms of commercial availability, Calcium-based detergents are far more common than their Magnesium-based counterparts. Somewhere back in the past (long before my time) Mg got itself a bad reputation. I seem to recall being told by my so-called colleagues (I use the word in its loosest sense) that it caused bore glazing on the Ford Tornado engine test, that it reacted badly with water and that the Japanese were so concerned about it, that they banned it's use in engine oils! That said, there was a time, perhaps for internal reasons, when Mg was cheaper for me to use than Ca. This is partly rooted in the fact that it's relatively easy to make a 400 TBN Mg Sulphonate whereas Ca Sulphonates tend to 'top out' at 300 TBN. So I picked up the Mg ball and ran with it and experienced no problems whatsoever! Oh how I laughed when I saw the Japanese patenting Mg-based oils for countering LSPI!! To the person who asked, once upon a time there were plenty of Mg only oils being sold all around the world. I don't recall any being sold in the US but in my experience the US is very 'herd mentality' based and as regards oil formulating is concerned, they don't do 'brave'. I sort of remember that Mg was big in Iran (nothing to do with me but occasionally something falls off the back of a camel and you get to see what The Competition is doing).

 

[SonofJoe]

Originally Posted by RDY4WAR

Sadly we have no way of knowing how many ashless detergents/dispersants are added. If they still claim a TBN of 12.0 with more than a 30% drop in detergents, then one must assume ADs.

Ashless dispersants all have a relatively low TBN (typically 25). A typical oil might contain 5% ashless so that will impart a total of 1.25 TBN to the oil, so small in the greater scheme of things. Be aware that in moving from Ca to Mg, you will always get a higher TBN for the same ppm of Mg 'metal' and that you will need less Mg for equal TBN. Although it's not easy to measure or indeed visualise, in adding overbased metallic detergents, it's the number of carbonate ions (and to a lesser extent, hydroxyl ions) that you should focus on; not the amount of 'metal'.

 

[RDY4WAR]

Great information. That's the kind of info I was hoping to get when I started this thread. What boron additives are added for mild detergency? If calcium is from CaCO3 and magnesium from MgCO3, what about boron? If you were still formulating today, would you include a hefty dose of boron?