Delvac 1 Sucks?

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I'm having some issues with a vehicle using Mobil Delvac 1, 5-W-40 Fully Synthetic Oil, in a turbo diesel Toyota landcruiser 4x4 converted to run LPG in conjunction with the diesel at the same time.

Heres the content today of my email to exxonmobil. Lets see what the experts have to say!

Quote:

Dear Sirs,

Could you please have one of your expert oils engineers/chemists advise me in writing - which is the best / correct Mobil oil to use in my vehicle?.

I have used your online web resources to try and ascertain this but been unsuccessful at finding the answer I seek.

1. My Vehicle is a 1992 manufactured Toyota Landcruiser 4x4 Turbo Diesel Station Wagon, with the IHD-T Factory turbo engine.

2. The vehicle is Non Standard, in that it has been modified by Australian Firm Diesel Gas Australia http://www.dieselgasaustralia.com.au/ to burn LPG at the same time as the normal diesel fuel.

3. I have been running Mobil Delvac 1 fully synthetic oil for at least 20,000 km's now, and getting the used oil analyzed by two independent laboratories now (Westrac Equipment in Perth Western Australia & Oilgaurd in the USA).

4. Your web based selection tool at http://www.datateck.com.au/lube/mobil_au/ recommends
MOBIL SUPER DIESEL 15W-40 or MOBIL DELVAC SUPER 1400 15W-40 or MOBIL DELVAC MX 15W-40 or MOBIL SUPER XHP 15W-40
It doesn't mention Mobil Delvac 1 5W40 Fully Synthetic Oil, which we have been using because we were advised at a US Based web forum that it was the best oil available anywhere in the world for this vehicle (Forum is BITOG = Bob Is The Oil Guy http://www.bitog.com).

5. Your Web Based Mobil Product Guide http://www.mobil.com/Australia-English/LCW/Files/2006_Mobil_product_guide.pdf, doesn't mention the oils that your web based selection tool recommends for the vehicle (Nor Delvac 1 Fully Synthetic 5W40).

The last two used oil analysis records for this vehicle by Westrac Equipment (attached) have shown wonderful results for low wear metals etc - however they BOTH mention elevated oxidisation and nitrate levels, suggesting that the vehicle is NOT operating within it's correct operating temperature range! Both samples were taken in our winter during cool weather and the vehicle temperature gauge never registered any high temps - it barely crept above cold.

Can you please advise if we should continue to use Delvac 1 5 W 40 fully synthetic oil in this vehicle? Its a VERY expensive oil to buy here at$20.00/litre - and due to the high oxidation levels we are not able to get extended oil change intervals out of the oil that we had hoped for. We don't believe the engine to be operating outside it's normal temperature levels, so are at a loss to explain the high oxidisation and nitrate levels being experienced.

Whether these are in some way attributable to hight EGT's (Exhaust Gas Temperatures) as a result of the LPG conversion - we are at a loss to say.

We also don't know if there is a more appropriate Mobil oil to be using for such a converted engine running both diesel and LPG at the same time.

I look forward to any advice you can provide us in this respect as to just which oil we should be using in this vehicle, given that Mobil Delvac 1 at this stage doesn't appear to be the correct one, if the used oil analysis results are anything to go bye.

Thank you very much in advance for an advice you can give.

Yours Sincerely


These are the 2 UOA's to which I refer.

LandcruiserUsedOilAnalysisJulOct200.jpg


Both found elevated Oxidisation and nitrate levels and question the correct operating temperature range of the engine.

So what is the right oil for this vehicle? - everyone on this website seems to suggest Delvac 1 synthetic 5-W-40 is the bees knees for every engine, but in this engine at least - while the wear metals levels are very low - theres no way we can get extended oil change intervals, if the oil oxidises and has elevated nitrate levels at 5000 km change time.

Why doesn't Mobile recommend Delvac 1 on their online selection link for that model and make?

Why don't they have the details of the oil their link recommends in their online selection facility at their oil details link? (Or Delvac 1 for that matter?).

It might be interesting to hear back what Mobil themselves have to say on all this!

The more I have to do with oil, oil analysis and so on, the more I begin to wonder if the whole oil lubrication game isn't some giant [censored] shoot run by crooks!

Cheers
 
Engines running on LPG have a much greater tendency to cause nitration rise in the motor oil. You can read about this online if you search using the right search words, like perhaps "nitration LPG oil". You should be able to find at least one site describing the lubrication issues with LPG-running engines as compared to gasoline or diesel. A few months ago I was able to find one but don't have the link saved. Some motor oil companies have motor oils designed specifically for LPG-running engines.

If you can't find any good info, let me know. I'll do some digging.
 
As JAG said, LPG and diesel are two different applications and usually there is a separate oil spec for LPG use. Now you want an oil to do both. Delvac 1 is an excellent oil for the wright application. It will be interesting to see what Mobil has to say. Just for general information, what oil is recommended by the company that did the conversion.
 
Ok if you average 3 kilometers per hour the oil has protected for 22,539 kilometers on this sample. 10 ppm Iron, 1 ppm Copper, 1 ppm Lead. Seems reasonable to me? But I am no expert.

You could try another oil and see if the oxidation/nitration levels are lower, I believe it would be hard to improve on the wear metals. Again I am not an expert but in averaging your wear with other posts in used oil analysis it looks great. Maybe I missed something?
 
The hours field is actually kilometers elapsed i.e. 7000 odd kilometers on that particular sample. On an oil designed for extended oil change intervals, such high oxidisation and nitration levels at just over 4000 miles seems a little extreme.

The amount of LPG burned compared to diesel is about 10%....so the bulk of combustible material is still ordinary diesel in t6hese systems. a small amount of LPG shouldn't raise Oxidisation & Nitrate levels that high in such a short distance IMHO.

The company doing the conversions make no recommendation regarding which oil to use after the conversion, other than keep doing whatever you were before the conversion.

They do make a claim that because the added LPG causes burn rate to go from 87% efficiency to 99% efficiency - that your oil as a result should be at least 12% less soot (carbon) i.e. that the oil should be cleaner and last longer - you can read the claim on their website - I posted the link.

It will be interesting to see what Mobil reply - I am betting they will play politics, and not comitt themselves either way!

Cheers
 
Originally Posted By: buster
You gotta love the title of this thread.
crackmeup2.gif



You gotta hope dude don't live near Doug!
28.gif
grin2.gif


Seriously - I think the letter may be a bit premature. Let's get a better grip on the situation before we blame the oil, if there is any blame to be placed at all.
 
I think you can still go a bit further towards 50 on your oxid and nitration. Look at it this way, if the engine wear levels are good and the oil is not getting thicker....run it up closer to the max limit of 50 on your oxid and nit levels. I think your getting a great service level out of this oil. Keep the same protocol up and develop a trend. If the oil is protecting the engine...you have nothing to worry about.And this oil IS protecting the engine.
 
Originally Posted By: Johnny
As JAG said, LPG and diesel are two different applications and usually there is a separate oil spec for LPG use. Now you want an oil to do both. Delvac 1 is an excellent oil for the wright application. It will be interesting to see what Mobil has to say. Just for general information, what oil is recommended by the company that did the conversion.
No special lpg oil for automotive use Johnny. I worked at a forklift Dealership for 17 years Factory trained on Nissan, Clarklift,Daewoo, Lindy Baker . They use mitsubishi ,Continental,Perkins ,G.M. ,Nissan and V.W engines All mfgs recommend engine oil "HDEO" These are the same as the respective engines used in their autos except continential and perkins "minus the auto required stuff.
 
I stand corrected.
cheers3.gif


Product Description
Shell Mysella® Oils are heavy-duty premium quality ash-free oils designed specifically for lubrication of high
performance gas engines which require an “ashless” oil. Formulated with select base oils and a Shell
developed ashless additive system, they provide excellent cleanliness and minimum wear. Shell Mysella® Oils
minimize combustion chamber and exhaust port deposits while minimizing oil viscosity increase.

Applications
• two-cycle and four-cycle stationary natural gas and LP gas fueled engines used in:

Note: LPG engines in mobile service typically require API SJ or similar quality level motor oils
 
Note: LPG engines in mobile service typically require API SJ or similar quality level motor oils [/quote] Stationary engines usually operate at a fixed rpm which leads to ring sticking from the additive package in motor oil made for "cars" .Kinda like 2 cycle oil differences between watercooled "boat motors " and aircooled "chainsaw motorcycle etc motors".
 
Quote:
..converted to run LPG in conjunction with the diesel at the same time.

Are we talking an aftermarket propane spray add-on? Nozzle(s) on the intake manifold somewhere, supplied with a high-pressure pump, possibly pulse modulated?
 
Response from Mobil Lube Line.

Quote:

Very weird oil analysis results. If I read these correctly, both these
results are showing the same numbers yet they are showing two different
oils!

What does this mean?

Also, did the converters recommend any specifications that the oil used
should meet? We have never received a call from a customer about a
diesel/LPG dual fuel system but, in the past, our Delvac MX has been an
excellent choice for LPG's as well as it's standard role as a diesel oil.
Delvac 1 leaves MX for dead so we can't see why it would be a problem in
your vehicle.

Regards

MOBIL LUBELINE


My reply

Quote:

es you read the results correctly...

However if you look closely - the Pennzoil long life tested first in the July Winter simple went for twice the number of kilometers (13000+) as your fully synthetic Mobil Delvac 1,(7000) before it was showing any similar signs of oxidization or nitrate levels, And the wear metal figures for Fe are lower in the Pennzoil than Mobile Delvac 1 fully synthetic. 10PPM versus 7 PPM at half the distance traveled.

I will forward this same email and results to the LPG conversion company for their comments regarding oil selection.

Many Thanks indeed


Their response

Quote:

My mistake as the test reports are poorly set out. Does ST stand for soot?
The numbers are quite huge for oxidation and nitration for both oils. Do
you know what method they use do determine this?

Regards

MOBIL LUBELINE


My Response

Quote:

Yes indeed I've spoken again today with the analysis lab at Westrac equipment, and they use the infra red method for Sulphation, Nitration, Oxidation, Soot and water readings.

He did seem to think that it is very unusual to see readings where Delvac 1 results were well below those attained with Dino Pennzoil at twice the distance travelled, because they test a LOt of Delvac 1 samples and always usually get very good results, reinforcing what we already know - that Delvac 1 is one of the very best oils on the market today.

Soot readings are high on this oil sample - in the past prior to conversion this engine on Pennzoil would run 5000km's and you could barely see the oil on the dipstick because it was clear yellow like new - almost no visible soot at all, whereas now it is quite black and high soot levels, as evidenced with the sample results.

The web site for Diesel Gas Australia makes claims that oil will be MUCH cleaner of soot due to a more complete combustion burn cycle with LPG at 99% efficiency compared to diesel alone at 87% efficiency. Our experience so far certainly isn't bearing this claim out.

We are considering adding sub micron and centrifuge filtering for the landcruiser in an attempt to keep the oil cleaner longer so we can get extended oil change intervals - howver if odixisation and nitration are an ongoing problem - we are unlikely to be able to achieve extended oil change intervals.

What occurs to me, - is that we are able to switch off the LPG injection at will with a switch on the dashboard.

We could for example when this next oil analysis result comes in (6000km's) - compare it to the October result & at the same time turn off the LPG injection for a 5000 or 6000 km period - and do the oil sampling again with Delvac 1, and get a comparison as to what effect the LPG injection is having on the Nitration and Oxidisation levels!

It would be a simple comparative test to perform.

It MAY provide enlightenment as to how much effect injection of LPG is having - also as we are having a pyrometer gauge installed - we could test EGTS with and without LPG to see what difference it makes.

Obviously we could also then compare soot levels as well...

I have a feeling it might be a VERY good idea to run this vehicle for ONE full Oil Change cycle of 5 or 6000 kms wthout the LPG and see what that tells us!

We would then have 4 samples results
1 with Pennzoil dino @ 13,000 km's
2 with Delvac 1 @ 6000km's Using LPG Injection
1 with Delvac 1 @ 6000km's Without LPG injection.

Maybe there is something to be learned from this as regards effects of LPG injection on engine EGT's, Soot levels, Oil Oxidation & Nitration levels etc

Many thanks indeed for your interest and assistance,


Their response

Quote:

One thing I picked up on is that they use Infra Red to do oxidations. Our laboratory does not as where you measure the peaks for oxidation also coincides with ester peaks that characterise synthetics, so you will get unusually high numbers. They should perform TAN's or Total Acid Numbers and even with TANs, our lab looks at the trend of results because TAN numbers
can also quite large. As far as soot is concerned what units is it expressed in?


I have no idea what units soot is expressed in and as it is a long weekend here can't ask for the next 3 days.

I did send the emails discussions and UOA results to the LPG injection manufacturing company Diesel Gas Australia, but so far no response at all as to whether different oil is required after a conversion. Presumably they are also sinking a few cold ones and putting another prawn on the BBQ seeing it is a national holiday weekend and who can blame them.

For the questions about how the system works, heres the link again to their website - knock yourself out and read all about it.

http://www.dieselgasaustralia.com.au/

For what it's worth, I have it installed on my 2004 7.3 PSD F 250 and it works a treat - no high oil oxidization or nitration numbers in UOA's for that vehicle.

If (when) I hear back from Dieselgas Australia, I will endeavor to include their recommendation if any.

Cheers.
 
This is something worth considering critically IMHO.

This is Diesel gas Australia's website quoted on oil cleanliness / engine wear.

Quote:

Engine Life


For those of you with experience with LPG vehicles, you would know the engine oil stays much cleaner between oil changes. LPG engines, when stripped, are almost spotless internally. On the other hand diesel engines are quite dirty internally and after an oil change the new oil quickly becomes black again.

In a diesel engine this black stain is soot. Soot is the result of incomplete combustion (the same as any wood fire stove). This soot (which is actually carbon) gathers in the combustion chambers, lining the top of the pistons, the injectors, the glow plugs and the valves. Some stays there and builds up into thick carbon deposits that must be scraped away when the engine is stripped. Some is blown into the exhaust manifold, coating the inside of the exhaust pipe or blown out the back as black smoke. The rest is washed off the cylinder walls by the engine oil, thus contaminating it and turning it black. This is why engine oil filtration is critical in diesels.

With enough carbon contamination, oil soon loses its ability to lubricate (viscosity) and clean properly, leaving abrasive deposits on critical components and allowing further carbon build-up. This causes engine wear - hence the need to change the engine oil on a regular basis. Anyone who changes their own oil will tell you that with diesels the oil becomes very black, very quickly. This indicates that the oil is doing its job but it is also already breaking down and losing its effectiveness long before the next oil change is due.

Image above is of Heavily contaminated diesel sump oil after 5000 km

Since LPG is a clean burning gas it does not leave soot behind. This is why the engine and oil stay cleaner for longer. With the Diesel/Gas system cleanliness is achieved slightly differently. The gas introduced acts as a catalyst encouraging a more complete diesel combustion. This means less soot (a lot less soot) which, in turn, means the oil stays cleaner. Now, if the oil is staying cleaner, that means it is not carrying as much contamination, and is therefore doing its job better and for longer. The upshot is reduced engine wear between oil changes and over the life of the engine (which is extended as a result).

Engine operating temperatures are not increased by running this system. Exhaust gas temperatures are reduced, since there is no longer fuel being burnt in the exhaust system.


From this you could be excused for believing that soot levels should decrease, oil should last longer and that oxidiation shouldn''t happen because EGTS are reduced.

Again from their website

Quote:

Does the engine run hotter?

No. Since more power is being produced the engine does not have to work as hard so it will not run hotter. Exhaust gas temperatures are also cooler since there is no longer excess fuel being burnt in the exhaust system.

And

Is there any extra servicing required?

We recommend changing the oil after 1000km and again at 5000km. The engine is now being cleaned internally, so the engine oil will be much dirtier to begin with as the carbon build-up is removed. After these two oil changes, the normal service interval can continue. These oil changes can be done by your usual workshop.

Service intervals are not affected by this system, other than the first two oil changes. Special oil is not required.
Bold = my emphasis.

Could the fact that - we are using LPG - be responsible for the elevated soot levels and Nitration oxidisation BECAUSE it is removing built up carbon deposits from the engine, in the first & second oil changes after conversion?

Is this why we are seeing the results we are?

Will subsequent sampling show reduced oxidisation and nitration and significantly reduced soot levels as they claim?

By turning off the LPG as I suggested above - am I not indeed then negating the ability to either prove or disprove the claims made on the website?

I have a gut feeling to just keep going with Delvac 1 and LPG injection - and see if what is claimed on the website turns out to be true.

We were never advised to drop oil at 1000km's after conversion, by the company or it's representative as a matter of interest.

Maybe they KNOW about this initial elevated soot levels and oil oxidation nitration problems immediately after conversion - maybe the oxidization & nitration being measured are residues from old oil built up in the engine that are being removed / cleaned up - by the introduction of LPG to the mix as claimed?

Just who does one believe?

Cheers
 
QUOTE: "Just who does one believe?"


Believe your UOA's and keep them up watching the numbers. Stay with what you are doing. Your wear is normal and the oil is protecting and doing it's job. After a while, you will know what you need to do. Your KM OCI will be developed around your UOA.

It will be interesting to note/see the Oxid and Nit drop if it does after a few OCI's. I believe your doing the right protocol and using the right oil.
 
Lpg is a gas when it enters the combustion. A F.i. or carbed engine the Diesel or gasoline is in ?? a mist ,real small droplets. So the combustion is better also lpg other than odorants to give lpg an odor or oil from the compresser that pumps the lpg ,it is somewhat pure.
 
I sure hope so.

Consider this. At $20/liter for Delvac 1, the landcruiser uses 12 liters or $240 per 5000km,s / (3000miles).

This is a LOT different than walking down to wally world for a 20 dollar 5 quart jug of oil for an oil change... the vehicle will need about 10 oil changes a year - $2400 for sump oil...to travel 30,000 miles.

This is why we were hoping for extended oil change intervals from the Delvac 1, to cut the cost of the oil back closer to the dino cost at about half that for the pennzoil we were using before the LPG conversion. Extending to 10,000KM's would mean we could halve our annual sump oil cost on this vehicle - a substantial saving back closer to the dino we were using and hopefully get the same or better protection.

At the moment we are getting the protection but at twice the cost.

We use the same Delvac 1 in the F250 7.3PSD, with the same LPG conversion. It uses 18 litres per oil change ($360 / oil change).

Thankfully I don't do many kilometers per year at all - last year was less than 10,000 km's or 2 oil chages...

Now - you guys I'm sure see a lot of F 250 7.3 powerstroke UOA's.

So since we are maybe blaming the LPG conversion for the high oxidation and nitrate levels, lets look at the UOA on dino Pennzoil for my F250 7.3 powerstroke 2004 model with 60,000 miles on it, it's a 3000 mile (5000km) sample.

The F 250 is also converted with the same LPG system.

80% of the 5000Kms (3000 miles) was heavy towing my boat pictured here at 60mph for 1200 miles each direction.
boattruck.jpg


We pulled the following from left egt's, transmission temps & turbo boost readings during various parts of the trip

P6300423.jpg

P6300424.jpg


This was our Pennzoil Dino UOA afterwards
F250OilAnalysis.jpg


Iron at 13 seems a whisker high IMHO considering she has oilguard bypass sub micron filtering and rare earth neodymium magnets on the main filter and the bypass filter cannister - I expected lower Fe levels to be honest.

Soot 29 seems a little high don't you think for a bypass filtered vehicle?

Oxidisation 46, Nitration 37, Sulphation 26

Seems like these numbers are well up there, just like the Landcruiser UOA numbers!

So - we are left with the same questions I guess....

IS the LPG conversion as the company website suggests - cleaning out old carbon deposits from on top of the pistons and inside the head, and blowing these down into the sump oil to be drained away at oil change time and after a couple oil changes, are we likely to see the F250 7.3 PSD ALSO coming clean in it's future UOA sampling?

Or

Do we have 2 different vehicles showing consistently the same thing after LPG conversion - higher soot counts, high oxidisation nitration and sulphation levels....despite all the claims from the companys website that the opposite should be the case!

The KM's travelled in the F 250 are less than the cruiser so the trends will be slower to reveal themselves in the F 250 due to lower KM's traveled.

Thats why I'm so interested in the cruiser results right now - I want to know where I am headed with the second vehicle as well.

If there are any problems in our future as a result of the LPG/Diesel conversions it would be good to know about them ahead of time - as stated - I can always shut them off at the switch on the dash if this proves to be the case.

Theres a LOT of oil cost between these two vehicles, 12 & 18 litres each (30 litres @$20.00/liter = $600 drained very 5000kms or 3000 miles).

If we are not going to be able to get extended OCI's out of Delvac 1 due to the LPG conversion - it would be nice to know that ASAP so we stop wasting so many $ on the synthetic oil if it won't hold up to extended OCI's as early UOA's suggest.

We are now talking about 10 oil changes x 2 vehicles maybe worth $6000/annum....and down under our F trucks cost almost $100K IF you can find one (Ford have stopped importing them).

So I'm talking about $130K plus in value of 2 vehicles and $6K a year in sump oil - for us at least, these are pretty important factors to get right, which is why the level of interest, amount of data number of posts etc.

Basicaly we have a lot riding on getting this right.

Cheers
 
Would the lpg cause too high combustion temps? I may be old fashioned but usually stock is best. I really don't know about lpg added to a diesel fueled engined other than reading the advertisements.
 
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