Delvac 1 Sucks?

[Shannow]

I've had this discussion with the LPG co-fuel people for ages.

A diesel runs on the lean side of stoichiometric (stoichiometric being where there is exactly mole equivalent air available to burn the fuel in the chamber), meaning that there's extra air available to burn some fuel.

As this margin reduces, temperatures go up. (Petrol engines are typically on the other side, as they lean out the temps go up)

That extra has an "extra" margin to allow for air filter restriction cutting back on the available air, and bringing combustion temps upwards.

The "chippers" use that margin to throw in extra fuel and get more power.

The LPG installers throw in a small charge of LPG that cannot auto-ignite because it is way too lean, then spark it with a normal diesel charge. Unlike most of the US based companies, gas is on all the time, not just a hill climbing boost.

They all claim "catalytic" action, and lower EGTs, but thermodynamically, more fuel means more temp. More temp means more Nox. More NOx leads to more nitration ???

There are a heap of LPG specific oils down here. There are a heap of Diesel specific oils. None list diesel/gas conversions.

It's unfair of these co-fuel installers to not do the testing and work out what's correct for their engines. It's unfair of them to say "should be no change", when they are talking garbage about the fundamentals of their conversions.

Can't expect Mobil to answer the question, as that market is tiny at present.

 

[Pablo]

Thanks Shannow - your answer speaks volumes as they say.

 

[Steve S]

I had the idea about the combustion temps. That is why egr is used to pollute the combustion and lower the combustion temps thus lowering Nox .Thanks Shannow. Stock is usually best.

 

[Flywest]

I guess we shall see.

Lets not forget - when saying stock is best etc that substantial gains have been achieved that might not apply stateside.

We have determined that our fuel economy is up quite a lot and our cost per kilometer has dropped 2c headed towards 3c as fuel gets dearer.

Don't sound like much but here at least the conversion on the cruiser cost $4100, less fed govt rebate $2000 & state govt rebate $1000. Out of pocket cost? $1100.

Number of KM's to recoup conversion cost?...between 55,000 - 33,000 depending on cost of fuel - i.e. less than a years motoring to be in front savings wise.

I have the Dyno graph for the F250 conversion I picked up and extra 23 horsepower at the rear wheels, and still meet Exhaust Gas emissions standards.

These are real gains not to be laughed at that save substantial $. Our govt pay us to convert because they don't want us reliant on imported oil. They will get thegrants funds back over the years of the vehicle thru excise (tax) on the LPG - so really they loan you the cash to convert if you like, against their future tax take.

So - who in their right mind doesn't want extended range and more horsepower and cheaper motoring?.

The issue I'm trying to get to grips with here is the other claims made on the manufacturers website - oil cleanliness engine longevity etc etc.

It may yet prove to be as the website claims, that the elevated oil soot, oxidization, nitration and sulphation readings we are seeing are partly related to testing methods (Infrared) used by the labs on synthetic oil peaking with the esthers as Mobil claim, and it MAY in part be the LPG buring off old soot and oil sludge buildup inside the engine from the piston crowns and heads valves etc.

If thats the case - we should see these figures reduce substantially in subsequent UOA's.

Not only that but these things we can test for - eg - the EGT's issue - I can switch on or off the LPG at will...and read the variance in EGT on the guage so we don't need to conjecture about whether egts must go up or down - we can watch the gauge for ourselves when we turn the LPG on or Off at will.

Next we can also if we choose switch the LPG off altogether at any time, and leave it off - for a full 5000 km oil change interval if we so desire and then compare UOA's between the gas/no gas intervals.

Something maybe not understood with the system fitted is that it is not a simple nozzle in th eair intake as ssome assume with LPG there all the time.

Its computer controlled and sensors dtermine when gas is or isn't supplied and how much.

E.g. Take your foot off the accelerator, there is n LPG being delivered, idle the engine - no LPG, just 2 examples - also - bury the boot and the vacuum from the MAP sensor line tells the computer how MUCH LPG to deliver and it is computer programmed to your individual engines requirements from the dyno results.

It is a little more sophisticated system than some seem to realize.

I am in complete agreement that the manufacturer should be doing this testing and publishing results and specifying appropriate oils for their conversions.

I am doing this testing because I need to know the answers and they cannot provide them for me at this point in time.

I will publish the results without fear or favor - regardless what I find.

I don't think we should condemn the technology out of hand seeing the gains we have already achieved.

It could yet prove to be the case that the co is right and the anomalous results are from the LPG burning off the previous deposited soot & oxidised nitrated and sulphated oil sludge deposited in the engine during diesel only running.

At this point my intention is to get this latest results back so we can see any trend (if any) a little more clearly, then run the next 5-6000kms and do the same again - THEN if we aren't seeing a rediuction - to try the LPG switched off for a oil change interval and sample again and following that if i am not happy to put one of those engine oil cleaner additive I saw on here thru, and see if that removes the deposits and allows lower soot oxidisation readings.

I will also check the EGTs with the LPG on and off and report back.

Lastly - we will work on the engines cooling system (maybe an oversized radiator core)& new water pump, and perhaps add an auxiliary oil cooler, followed by an intercooler for the turbo.

We also intend to add both bypass and centrifuge oil filters, in an effort to keep the oil cleaner.

Maybe any or all these things should be done, when converting to LPG - who knows - but one step at a time I intend to find out!

I will be UOA testing all the way thru this process.
It will be an interesting walk in the park IMHO.

The funny thing is this.

You can have the landcruisers here - converted to run a diesel V8 chev 6.5 litre engine that naturally aspirated puts out 170hp.
They are heavy, and have a ridiculously small 6 litre sump and as a result are notorious for overheating.
It costs about $16 grand + to have the conversion done professionally, all road registered

The turbo 4.2 litre 6 cyl toyota engine makes about 150 HP stock standard and with the LPG about an extra 10% or 15Hp... meaning 165HP....or about the same as the Chev conversion.

Add on an air to air intercooler, and you gain about another 20 hp..getting up to 185Hp or thereabouts..

The 7.3 PSD turbo only makes 210 HP in standard trim...

These old 4.2 turbo land cruisers with a little bit spent on LPG and an Intercooler (Net out lay after govt rebates about $4 grand are way ahead of the Chev 6.5 liter conversion in power weight and oil capacity etc etc, at a quarter of the cost.

I think this particular path is worth pursuing but only one step at a time - gotta sort out the oil bidness first, then some filtration and a few more toys...and who knows where this will end.

Hopefully not in a disaster.

Worst comes to worst, and we blow up the cruiser 4.2 we can always put the Chev 6.5 into it and add a turbo, intercooler, and the LPG and probably be well over 300 HP....eating F 250's and Dodge duramax' for lunch!

Cheers

 

[JAG]

Originally Posted By: Flywest
It may yet prove to be as the website claims, that the elevated oil soot, oxidization, nitration and sulphation readings we are seeing are partly related to testing methods (Infrared) used by the labs on synthetic oil peaking with the esters as Mobil claim, and it MAY in part be the LPG buring off old soot and oil sludge buildup inside the engine from the piston crowns and heads valves etc.

I recall that FTIR oxidation values I've seen on this site of virgin Delvac 1 were near zero. Considering the importance of what you are doing, I think it worth it to send a virgin sample of your Delvac 1 to the same lab you've already used. Of course, you still have the nitration issue (nitration of virgin D1 should be ~zero).

I thought you said early on in this thread that coolant temps have been barely high enough to register on the gauge. If so, doesn't that indicate something isn't right with the engine?

 

[jmac]

based on the readings of your gauges, I think your egt temps are 100 - 200 deg. lower than a truck pulling a similar load on straight diesel in that engine. Thus confirming at least one of the manufacturer claims of lower combustion temps.

 

[jmac]

#2, unless you have a pre-2000 engine the 7.3 hasn't put out that low 210 hp since then in stock. Mine came at 250 hp peak and a very simple chip puts it at near 300 hp with no extra changes.
Adding the lpg full time should be upping the hp a little as well, don't know how much.

 

[Flywest]

More than 210 huh?

Well mines a 2004 manufactured 7.3 - remembering you guys in the United States went to the 6 litre in 2003 - while we downunder still got the 7.3 in our Brazil built F250's right up to 2006.

Thats the dyno figures for with an without LPG switched on and the figures don't lie. 210 HP without LPG and 233 with so i picked up 23RWHP bye the looks.

Theres no chip on her, she is stock standard in terms of not having any power chip, because I don't want to destroy the transmission....which at only 60,000 miles when I first bought her, was already giving very bad UOA analysis results on the ATF.

Since then the F250 has had:-

A new pan filter:-

A alloy deep pan sump,

A Filter on the transmission line.

An auxiliary Oil Cooler out front for the transmission.

I also have water misting sprays behind the grill that I can hit a switch on the dash to 12V deck-wash pump and spray water over the radiators while hauling if the trans temps or EGT's climb too high.

Thats fed by these two stainless steel tanks.

You can see the air compressor and deck-wash pump mounted up on top of the aluminum LPG tank enclosure, on the RH side alongside the stainless water tank.

This is a second stainless water tank mounted underneath - and opposite side has 66 US Gallon Long Range fuel tanks (2).

Non of the "improvements" are added to increase HP so much as - nearly everything done is to try and ensure longevity of the engine and Auto trans while hauling.

Probably time I sampled the ATF again and see how it holds up this time compared to last time.

But the HP figures are probably pretty accurate.

The extra 66 Gallons fuel & 55 gallons of water & 38 gallons of LPG probably adds a fair weight to the truck beyond standard when you add in the weight of the tanks as well as the fluid they carry.

Cheers.

 

[Johnny]

Wow, that's approximately 1,133.67 lbs of extra liquid plus the weight of the tanks.

That's quite the set up you have there.

 

[Flywest]

Indeed,

It's a lot different here to the USA in many respects, you have approaching 300 million residents (and business / support services) in a landmass about the same size as Oz where by contrast we have only 20 million population - where 18 million of those live on the east coast.

Out here in the west I can drive 1000 miles & might pass 4 gas stations - not one of whom employ a mechanic, or repair/sell tyres even.

So you have to be very self reliant, it is not as tho - wherever you break down, there is going to be a Ford Dealership & tow truck nearbye.

Likewise our F250's like mine cost around Aus $100K IF you can find one since Ford decided to stop importing them.

To some of you a $20 OUA sample is sort of a quick looksee just in case somethings untoward.

When I set out with charter boat in tow and a booking for some overseas guest to fish the wild remote areas of Wild West Oz - it's like a launch of the space shuttle in preparation terms - everything has to be right - otherwise many thousands of $ are at stake as well as our lives, in some of the remote spots.

That fresh water storage comes in handy for cooling the big girl down on a hot day but I REALLY carry it for drinking (hence the stainless steel construction) or in a worst case scenario - for putting out tyre fires on the boat trailer, (cooling the rubber down so it stops self re - igniting from heat).

I carry about 5 Fire extinguishers between boat and vehicle - but sometimes that wouldn't be enough without the water and hose and high pressure pump to cool the molten rubber down.

Theres no fire brigade where I go...
Likewise often theres no fuel.

Heres a fuel bill when I pull in and fuel the F250 & boat trailer.

F250
250 litres diesel @$1.70/litre = $425.00
146 litres LPG @ 95c/ltr = $138.70
Boat
320 Litres ULP @ $1.65/litre = $528
7 x 60 litre drums ULP @ $1.65 = $693

Total fuel bill, $1359.70

Between boat and trailer I carry over a tonne in extra fluids weight when full.

That would let me tow the boat about 900 miles up the coast and fish for 3 days after which I would refuel again at a similar cost.

Like I said - I might complain sometimes about an oil product or oil sampling but for me at least - there are serious implications if a product doesn't stand up to scrutiny.

I try to use only the best.

Cheers

 

[Flywest]

Ohh I tallied that cost incorrectly it was actually $1784.70

Today I got an email response from the auotgas injection system manufacturer installer.

Quote:

Good afternoon Shann,

I am back in the office and catching up on emails etc. In answer to your query about engine lubricant recommendations, our best advise is to adhere to the engine manufacturer's recommendations for lubricants and service intervals. Those clients that we have with heavy road transport equipment that follow SOS or similar have never reported elevated levels of any kind so I am at a loss to explain your results.

The only suggestion I could make would be to run a series of gas on and gas off trials (using a mineral oil) to verify your results although with all the running variations this could lead to more misleading results and the extended interval you desire would not be a good idea with mineral oil.

Cheers
Mark Collins

Lovato Autogas WA
Diesel Gas Australia


Thats what I intend to do eventually, but not until I run one more OCI with the Delvac 1 (making 4 in total) so that we know if the levels clean up as the manufacturers website suggests, or if indeed the oxidization nitration and sulphation levels as well as soot remain high.

Once that trend is clearly obtained - THEN I will run a couple OCI's with the LPG gas swithced off and compare.

After that - it will be back to some dino oil and give the Delvac 1 a miss if it cant perform as it is meant too for extended OCI's.

Thats the plan at this stage!

You'd think the Manufacturer of the System would be a little more interested, perhaps once I am finished, and get the data - if it doesnt agree with his website claims I will advise the advertising standards commissioner of the claims made and the results that testing reveal - there are big fines for blatantly false advertising in our nation - he will in effect be forced to alter his claims on his website (remove them) or print the truth.

We will see.
More testing yet before we ge to that point tho!

Cheers

 

[Flywest]

I believe I may have stumbled onto something that a LOT more of us should know about - with regard to Diesel Engine Design and the right oil to use in that engine.

Heres a link where you can download and read the article, published I believe By Castrol.

http://www.box.net/shared/static/mcyb32zcwo.doc

If you have a Japanese designed / manufactured Diesel engine as opposed to an American or European designed diesel - then you NEED to know about this issue IMHO.

It's probably important enough to warrant its own thread!

Further to the above....

Heres another link to read, with regard to the particular issue with Toyota Landcruiser diesel engines and oil problems and how they can relate to early demise of the big end bearings for which a certain model run was is notorious and how this is probably caused by using the WRONG oil in these high temp Japanese designed built diesel engines.

For those on here willy nilly suggesting that their favorite oil used in an American Designed built diesel must be good for others with Japanese designed built diesels vehicles because it works OK in the Dodge / Ford / Chev etc vehicle is BAD advice people.

http://www.markerink.org/WJM/HTML/80bigend_oil-analysis-scam.htm

Please take the time to read this thread above entitled:-

Quote:
What oil companies don't want you to know about oil
(inspired by the failure of big end bearings on Toyota Land Cruisers HDJ-80 with 1HD-T engine ('90-95))


Lastly, to see why all the fuss about the big end bearings and what potentially CAN & regularly DOES happen using the WRONG diesel engine oil in a Japanese built diesel engine - you need to look at this link if ONLY to view the pictures of failed big end bearings due to the poor properties of oil we are being supplied KNOWINGLY by Big Oil companies for these high temp Japanese Diesel Engines.

http://www.lcool.org/technical/80_series/td_bearings.html

It is my contention that there are ONLY a few oils suited to use in these types of vehicles, with VOA calcium levels between 3500-4000 as listed below.

Caltex Delo CXJ 15w40 (the J is for japanese) mineral oil,
Castrol J-Max 15w40 mineral oil,
Amsoil Marine oil 15w40 synthetic oil,
Amsoil series 3000 5w30 synthetic oil,
I know BP in Europe makes some nice high calcium synthetic diesel oils
also but I don't know names or product codes.
My favorite of the above is the 5w30 amsoil but it is seriously
expensive and unless you are running extended drains supported by
routine oil analysis it is too expensive to drain every 5000km.
Pennzoil 15-W-40 Diesel Longlife.

Read and understand this:

Quote:

---The oil sold in Japan typically has calcium based detergents in it at levels of 3000-4500+ppm (parts per million) this is a very detergent oil compared to a lot of oils formulated for american engines (700-2500+ppm magnesium based detergents, magnesium based detergent is thermally unstable at normal working temps of a japanese diesel engine that is why it is not used in japanese OEM oils) as a side benefit extreme levels of calcium have a very strong bearing pacifying affect reducing the bearings susceptibility to chemical attack by its own oil which contributes to the onset of subsurface fatigue failures.
Synthetic oil per-se is not a fix (or prevention method) you want an oil with low or no magnesium and preferably in excess of 3000+ppm calcium based detergents.


Using typical American formulated oils with high magnesium and lower Calcium levels can lead to this:-

Heres what happens if you ignore the type of UOA results we've been getting from the so called "Miracle" Mobil Delvac 1 Fully Synthetic, which has waaaay too low Calcium levels for Japanese designed built diesel engines and too much magnesium which isn't stable at the temperatures these engines operate at.

Perhaps as I said - with so many Japanese vehicles being imporrted now into the USA (I think you are getting more of their diesels now?), maybe this is a timely heads up worthy of it;s own thread for those who are considering sticking with their usual favourite USA brand of diesel oil in a new Japanese designed built diesel engine.

Don't do it is the simple answer.

Not unless you want to be paying for premature engine failure just outsideof warranty - due to using the WRONG USA manufactured oils designed for USA designed / manufactured diesels being knowingly sold to us for Japanese designed built engines that require much different oils lower in magnesium and higher in Calcium.

I recall a good thread here a while back asking the question "where is the magnesium going?" about disappearing magnesium in reformulated diesel engine oils VOA's....

Maybe a few more people with Japanese designed build diesel engines need to take note of this detail that non of the oil companies seem to want us to know!.

Someones got to pay for all these engine failures...and the oil company's would apparently prefer it was the engine designer / manufacturer!

Cheers.

 

[JAG]

That Caltex article is from 1995 and as you know HDEOs have changed significantly since then. The oil recommended in that article for North American diesels is Delo LSA which is no longer produced. My computer is blocking access to the other link (Castrol maybe)...I'll read it tonight.

Delo CXJ is still produced which is what the Caltex article recommended for some Japanese diesels. Delvac 1 5W-40 meets JASO DH-1, which is the main 1 of the 5 specs that Delo CXJ Multigrade SAE 15W-40 meets which are:
• JASO DH-1
• API CF
• "Japanese CD Plus" industry guideline
• "Japanese CD" industry guideline
• Double length Mitsubishi 4D34T4 wear test

http://www.mobil.com/USA-English/Lubes/PDS/GLXXENCVLMOMobil_Delvac_1_5W-40.asp

 

[Flywest]

Go into the Virgin Oil Analysis for Delvac 1 and you will see that the calcium levels are around 2500 or less while the magnesium levels are up considerably.

The article quite clearly states that such oils aren't suitable for the high temp Japanese diesels.

Anyone says "the thread has run it's course" obviously didn't take the time to read the articles linked - NOR the litany of engine failures attributable to these particular engines and inappropriate oils.

The evidence is pretty overwhelming - our own results clearly show the oil to NOT be performing - and all these other examples - as well as info from one of the oil company's themselves explaining why.

Why the attempt to "shut down" a thread where something potentially valuable is being learned?

Whats your stake in it that you would want to shut down such discussion..

Article from 1995 or not - the vehicle I'm discussing is from 1992 and this new Delvac isn't performing up to its reputation in this particular engine, despite whether it supposedly "meets" any kind of Japanese engine standard - it's clearly formulated a lot different to what the Japanese themselves use.

The same engines in the same vehicles in Japan are NOT suffering the large numbers of big end bearing problems that we are seeing in Australia using oils sourced, designed, & blended principally from USA.

I don't see why the fear myself...

It's just information - some of it very GOOD information and straight from the oil company's mouth.

The websites with hundreds of affected owners speak volumes for the existence of the problem.

I guess those with something to lose or with some vested interest maybe can be excused for "running scared".

Frankly this is starting to show that indeed Delvac 1 Sucks when it comes to Japanese Diesels and it shows quite clearly WHY - because it isn't formulated the way these engines require.

Who knows how many owners of such vehicles out there could benefit from such knowledge.

Wheres the harm in displaying it here?
Isn't that what this forums all about - sharing information?

Edit, JAG these above comments aren't directed at you, Arkapigdiesel? (or a mod?) deleted his comments saying words to the effect that "this thread has run its course" - making my above comments appear out of context!
Sorry for any implied inference otherwise.

Re the Mobil Delvac link provided JAG, this comment interests me.

Quote:
Virtually all diesel powered equipment from American, European, and Japanese equipment builders


Bold is my emphasis, virtually all - could this be one of the Japanese engines that DOESN'T do well on Delvac 1 ?.

The results so far sure look that way!

Cheers.

 

[D-Roc]

I haven't been a part of this thread Flywest, but I do see your comments going in the direction of an attack on the above mentioned oil. Maybe not my place, but instead of making comments like you have about the oil, downplay it...just a little. There is an oil that is quite prominent here that I flat out do not trust that makes great claims to meet all the standards- but it didn't work for me- I try not to attack it. Unfortunately it is trial and error finding something that works.
JMO...

 

[buster]

Feel free to bash any oil. Just be prepared to back it up thats all. I don't know enough about it to say either way.

 

[Flywest]

Attack and Bash... Your worlds not mine!

OK the titles designed/intended to get you to look, and it clearly did, but I haven't bashed or attached Delvac 1.

I've merely pointed out, it isn't standing up to the claims made for it in two separate vehicles so far, one of which is a Japanese Diesel engine the other a USA Made engine.

I normally would attack or bash an oil that didn't work for me EXCEPT....that the [censored] oil is over $20 a liter and we are on our 5th x 20 liter drum (Yes $1000 worth) and it simply SUCKS!

Sure - I can walk away from Delvac 1 and say nothing - but who does that help?

Mobile Delvac gonna refund my grand outta pocket for a product that clearly from it's design - the available information and the provided UOA's - isn't up to the tasks they claim it is?

When a company produces a product that doesn't meet the claims and extortion expense it demands, then they should man up and admit they got it wrong and pay for their mistakes.

Thats not likely to happen - instead I should slink away into the dark and say nothing for fear of upsetting someone?

In my trade over 20 years If I made you a new kitchen or furniture and it wasn't what I said it would be - if it wasn't appropriate to the task you described to me at the outset - if it was faulty in design or workmanship - you wouldn't pay me!

I took a LOT of pride in my work always - what a shame Mobil apparently don't operate the same way!

Delvac 1 Sucks in both my vehicles based on the results so far and the available information I've found on the net & produced here.

Thats not an attack or an attempt to bash - its a purse statement of fact!

The oil sucks for our use - for whatever reasons clearly Mobil and the LPG Manufacturer / Installer have no idea why - but plainly others out there in the community do based on the info I've provided.

If these vehicles were yours - if this was your $130K worth of capital equipment, you like me would be here looking for help to find answers to, "what oil will do the job we need".

Before you criticize me, for looking out for my own interests - first walk a mile in my shoes, - then at least - you'll have a free pair of shoes and a 1 mile head start!

I stand by my claims that Delvac 1 sucks in my 2 vehicles and I've provided mountains of evidence to that fact!

Thats not an attack nor is it bashing - its factual - and very claim has been backed up with facts!

Oil at 20 bucks a liter ought to perform. It also ought to have a money back guarantee that it will at that price. When it's proven NOT too - then the company needs to pony up to make the problem go away!

That or I get my grands worth of satisfaction proving that "Delvac Sucks" across varuous forums of the internet worldwide - not hard to cost a company like Mobile many thousands of times the losses I've incurred with their oil, just in bad publicity alone!

If you don't want to get people pizzed off to that point then don't gouge people on the oil price and make claims for it that it can't meet.

Lets see Mobils profits on Delvac 1 shall we?

1 barrel = 42 gallons = 158.9873 liters

They buy oil at say US $100/ Barrel thats about 63c a liter.
They blend it and synthesize it and add their addpack etc package it and charge me $20.00/liter.

Gee a 3100% Markup - on a product that doesn't work as claimed?

If that ain't worth of an attack or a bashing = then I'd sure like to know what the heck is?

Cheers

 

[Shannow]

Flywest,

The product must meet the standards that it states. But that doesn't necessarily mean it's the best in your engine/application.

the Japanese diesel issue is something I've been fighting for 4 years now.

http://www.bobistheoilguy.com/forums/ubb...true#Post537040
http://www.bobistheoilguy.com/forums/ubb...true#Post533074
http://www.bobistheoilguy.com/forums/ubb...true#Post532857
http://www.bobistheoilguy.com/forums/ubb...true#Post532727

 

[Flywest]

Looks like I'm not the first one to run into these problems then Shannow!

Maybe the fact both engines have been run in the past on dino oils and are now running on delvac 1 accounts for the high soot, oxidation, suplhation and nitration readings - I don't know.

I am thinking I will do modifications to both vehicles to re route the EGR out the back instead of thru the engine and that might lower soot levels.

We will run this next OCI in delvac since the wear numbers are still good and see what results we get back but I'm not overly hopeful as far as the Landcruiser is concerned.

Time will tell.

Cheers

 

[tdi-rick]

Originally Posted By: Flywest
Go into the Virgin Oil Analysis for Delvac 1 and you will see that the calcium levels are around 2500 or less while the magnesium levels are up considerably.

The article quite clearly states that such oils aren't suitable for the high temp Japanese diesels.



there is more to anti-wear than just high calcium levels. look at the Boron levels of D1 vs cheaper oils, markedly different.

In my experience D1 does very well in Nissan TD42T's. Our UOA's show reduced wear metal numbers across the range compared to 3000ppm+ calcium oils.
I believe that Caltex ran it's entire fleet on Delo 400 to prove to the Japanese manufacturers that they were barking up the wrong tree on their oil choices, but it fell on deaf ears.

It's my understanding that Toyota's problem was an engineering one. The other Japanese manufacturers weren't having any problems with their engines running in Oz at the same time, using the same spec oils.
BTW, I don't believe the ZD30 Patrol issues were every fully explained, at least not publicly. You still hear of the odd ZD30 engine blowing up