Adding 2-Stroke oil to Diesel

[Old.Tony]

I did run it for some time, but don't forget that there's a distinct difference between petrol and diesel - diesel is oily to begin with, and chemically combines with the 2-stroke oil.

The 2-stroke oil I was using was a fairly high grade mineral oil (Castol Activ 2T) which was ultra-low ash (JASO-FC). The 2-stroke oil used in lawn mowers doesn't have to be low ash at all - and that must be partly where that sludge comes from.

Why does a 2-stroke fuel mixture foul up plugs in a 4-stroke engine when 2-stroke engines have plugs too? Probably due to a couple of things, I'd imagine, like the spark plug gap and the fact that the combustion process continues for longer in a 4-stroke while the piston reaches the bottom, then as the piston rises it's pushing the combusted gas (plus any ash etc) past the spark plug. It's entirely possible that small engines designed for mowing lawns aren't as efficient as car engines (look at valve placement in a Briggs and Stratton engine) so maybe not all the fuel combusts properly (who would have thought that, eh?).

 

[tweak'e]

petrol engines do not burn oil well. it tends to coat the combustion chamber which means its not mixed with air so will not burn well.
diesel on the other hand, burning oil in an oil burner is obviously not an issue. diesels will run on a large number of oils. they all burning faster/slower, more/less ignition lag etc. how well depends on if its matches what the engine is designed for.
2T has no problem burning. the question is, what are the 2T additives doing and is it worth doing?

 

[d22dave]

the question is, what are the 2T additives doing and is it worth doing?

71 pages on this thread, and that question still hasn't been answered with any sort of factual scientific answer.

Oh well, I tried it and I'm still undecided. But as said above diesels will run on near anything oily, old diesels I can't see a problem but the newer the vehicles and fuel systems could be different, but for me I will still do it once in a blue moon.

 

[tweak'e]

i don't think you will ever get a scientific answer.
no one will spend the $$$ and no oil company wants that info as it may make them liable.

i think its probably more important with modern diesels IF you cannot get the correct fuel for them or have contamination issues. with high egr engines, having something help clean out the soot is not a bad thing.

 

[bradm84]

I have just read back through a fair few pages of this thread but without reading all the way back not sure if this question has been covered already. But when you guys are using the 2 stroke oil, are you running the diesel down to empty and then filling it up and adding the 300ml every time.
I'm mainly asking cause I generally fill up when it gets to roughly about a quarter full. I would then have to figure out how much 2 stroke to put in to keep it at the right ratio as putting another 300ml in would be additional to the little bit still in there from the previous tank... After a few times of doing that the ratio would be a bit more concentrated... Or is not that crucial to be spot on with it...
How do you guys go about keeping the ratio right?

 

[308bever]

so have you quit using it OLD TONY?

 

[Old.Tony]

Not yet, I still put some in now and again. Won't use Valvoline because it doesn't know what I mean, but the Castrol is still good to go. I should point out that I still have the original DPF, I still have my original injectors, fuel pump, SCV, fuel lines, although I've now got 150L of tank. Engine is wonderfully smooth and we've just passed 180,000km on the odo.

I've put half a litre into 80L of diesel (well, I guess that makes it 79.5L of diesel) and I've heard up to a whole litre in 80L is just fine. I wouldn't panic about the ratios.

 

[fourocker]

I have just read back through a fair few pages of this thread but without reading all the way back not sure if this question has been covered already. But when you guys are using the 2 stroke oil, are you running the diesel down to empty and then filling it up and adding the 300ml every time.
I'm mainly asking cause I generally fill up when it gets to roughly about a quarter full. I would then have to figure out how much 2 stroke to put in to keep it at the right ratio as putting another 300ml in would be additional to the little bit still in there from the previous tank... After a few times of doing that the ratio would be a bit more concentrated... Or is not that crucial to be spot on with it...
How do you guys go about keeping the ratio right?

As old tony said, don't sweat it about the ratio too much, the little bit of diluted remnant in the final quarter tank won't matter.

 

[Rumpig]

I have just read back through a fair few pages of this thread but without reading all the way back not sure if this question has been covered already. But when you guys are using the 2 stroke oil, are you running the diesel down to empty and then filling it up and adding the 300ml every time.
I'm mainly asking cause I generally fill up when it gets to roughly about a quarter full. I would then have to figure out how much 2 stroke to put in to keep it at the right ratio as putting another 300ml in would be additional to the little bit still in there from the previous tank... After a few times of doing that the ratio would be a bit more concentrated... Or is not that crucial to be spot on with it...
How do you guys go about keeping the ratio right?

200/1 is 300ml for 70 litres (or so ), that'd be 75ml for every quarter of a tank

 

[Triple-one]

i don't think you will ever get a scientific answer.
no one will spend the $$$ and no oil company wants that info as it may make them liable.
.

http://www.fuelexpert.co.za/2strokeoilindiesel.php


http://www.fuelexpert.co.za/2-stroke-oil-in-diesel-technical-study.php

 

[Black_Outlaw]

Tl; dr

While this study does show that no detrimental effects on lubricity or exhaust emissions are caused by the addition of 2-stroke oil to diesel, fuel injector fouling is a possible risk. The trace amounts of metals such as zinc found in most lubricating oils, including 2-stroke oil, can cause rapid injector fouling. While some high quality diesel fuels on the market, such as Sasol turbodiesel™ ULS, contain detergency additives that can clean up these sort of deposits, metal contaminants can still be harmful. The diesel particulate filter (DPF) fitted to most modern diesel vehicles is very effective in capturing soot (carbon) which can be readily burnt off (regenerated) when blocked. Other contaminants found in oils, such as zinc, result in ash formation in the DPF which eventually results in a permanent blockage and premature failure of this costly component.

It would therefore be irresponsible to advise or condone the use of 2-stroke oil in diesel and this practice is not recommended.

7. Conclusions
based on the results of this study, the following conclusions are drawn:

At a 200:1 volumetric blending ratio, 2-stroke oil has a negligible effect on diesel lubricity.
All diesel fuel sold in south africa has to meet the sans 342:2014 lubricity specification to ensure the proper protection of diesel fuel pumps and injector systems.
The low sulphur diesel products sold by sasol contain lubricity improver additives which are far more effective than 2-stroke oil.
At a 200:1 volumetric blending ratio, 2-stroke oil has a negligible effect on diesel cetane number.
No measurable effect on all other regulated diesel properties was measured at a 200:1 dose of 2-stroke oil in diesel.
2-stroke oil can contain around 16ppm zinc, or higher depending on the formulation and batch.
Trace amounts of zinc in diesel are known to rapidly accelerate injector nozzle deposits.
Engine test results show that a 200:1 blend of 2-stroke oil in diesel results in a 2% loss of engine power in a 16 hour test due to injector fouling, a risk that would apply to any common rail diesel engine, but could also worsen fouling in older engines.
Vehicles fitted with a diesel particulate filter (dpf) in the exhaust system could experience reduced dpf life due to the collection of ash and metal based contaminants in the filter over time with the continued use of 2-stroke oil.
The abovementioned results should hopefully clear up many of the public misconceptions around the use of 2-stroke oil in diesel and highlight why both oil companies & engine manufacturers do not recommend the addition of any after-market additives, ie. 2-stroke oil, to the fuel tank. It is also good advice to use fuels from reputable outlets backed up by the technical support of a competent fuel company to enable the best engine performance and durability.

 

[Jased22]

Yep fu#k that i would never put 2 stroke oil in my tank. Liqui moly clean and boost for the win.

 

[Old.Tony]

Excellent input. It's more definitive testing than I've seen from anywhere else. All I have is personal experience - I've used a fair bit of the old Castol Activ 2T in my car and it's still running well. I have run through a couple of bottles of Liqui Moly injector cleaner but with nearly 190K on the clock now, you'd expect that even if I wasn't using 2T.

The performance graph (@4400rpm) certainly tells a story though, quite clearly.

So in summary, there are some negligible benefits from using 2T, but the zinc makes it an issue in the CR diesel? That may invalidate its use. However, (all coins have two sides) the zinc may also help with any pitting in the surfaces, increasing the lifespan of the engine.

What a shame there was no EGT information, along with comparisons at slightly higher levels. 200:1 in an 80L tank means about 400ml. Some proponents use up to a litre in their tanks. I was using 300ml in my 80L tank (now 150L tank) which represents a 500:1 ratio. Am I not using enough?

 

[user 10312]

Good reading! As I suspected the the reduced noise from the engine is not from the increased lubricity in the fuel but rather the effect on the Cetane rating. I have put 2 stroke in my fuel as an experiment and the engine was way more quite but it doesn't mean it's doing it any good. I'll be sticking to lubricity inprovers that come built in with the diesel.

 

[Stelianos]

from my experience additives in fuel work just as a placebo effect to owners who want to do something good for their car, but end up with the reverse effect, being present on all maintanance done so far to the truck my mechanic (and also husband of my wives sister) has used an engine flush at 100,000 kms i payed something like 50 euros and injector cleaner on last tankfull before the service to replace the contaminated filter as well, did it run any better? no but 167,000 kms it runs pretty damn good!.
good additives are used once and do work, cheap supermarket ones you have to use every tank etc are just there to take your money (same with oil in fuel this myth is around since the 80's at least!) good diesel has all the additives you need.

 

[tweak'e]

http://www.fuelexpert.co.za/2strokeoilindiesel.php


http://www.fuelexpert.co.za/2-stroke-oil-in-diesel-technical-study.php

theres a few things not quite right with that testing.
one is minimum cetane number is not 45 as shown on the graph, its 51. which makes the straight diesel just above the requirement which is what you would expect. you would not expect to have 45 cetane fuel testing at 51 cetane.
2-stroke oil gives minor increase which matches the change in engine noise people have reported.

the lube sounds about right, minor increase in Lubricity. if i remember right the old diesel was well above the minimum required.

the injector fouling test, which is their own test, sounds odd.
dynos can't really measure changes that small, maybe why they havn't shown the power readings. both power and change in fuel flow can be result of multiple things. to say its only injector fouling is a leap of faith.
especially when its opposite of what most real life examples have shown.
2-stroke oil may have zinc but its also has a lot of detergents designed to clean combustion chambers.
you also have to be using a huge amount of oil to foul injectors as seen on oil lossy systems on big rigs (ie burning engine oil).
same thing with DPF's. most have shown extended dpf life not rapid dpf clogging which is opposite to their theory.

the conclusions don't match the testing. the "conclusions" are mostly theory rather than actual results of the testing.

the way that this is written makes it look like they made the results fit their own conclusions. eg adding the bit about watering down diesel. use of "negligible" without defining what negligible is.

one thing they do get right is that if you have good quality diesel you shouldn't use 2-stroke oil. but most of us have run into poor diesel at one point or another.

the other factor is if th efuel is correct for your engine. i think the TD42 requires 45 cetane while the ZD30, YD25 requires 50 cetane. last time i check, some years ago now, aussie fuel was 45 cetane.

 

[Old.Tony]

Aussie fuel varies. Shell were offering a flat 49 and if you didn't like it, you needed an Everyday Rewards Card.

Over at Caltex they were offering 51 cetane along with BP. BP have begun introducing "Ultimate Diesel" which has a cetane of 55.

It's hard to comment about Mobil. They don't retail much any more, mostly wholesaling to 7-Eleven and others. The rumour is that the tanker drivers have been mixing up to 20% biodiesel in their loads so buying from Metro/United/7Eleven carries an unknown with it. I have no idea about Gull.

 

[Nick-palmer1]

I'm reviving an old thread here and probably going to open a whole new can of worms but I've found this which i thought a few people may be interested in.

http://www.baileysdiesel.com/on-hig...stroke-oil-diesel-modern-common-rail-engines/

 

[Soybean]

I also saw this on the net.
Will be giving it a go next tank, until now I've been using fuel doctor only.

Sent from my SM-G900I using Tapatalk

 

[Black_Outlaw]

I'm reviving an old thread here and probably going to open a whole new can of worms but I've found this which i thought a few people may be interested in.

http://www.baileysdiesel.com/on-hig...stroke-oil-diesel-modern-common-rail-engines/

And we all know that the Nissans run a Denso Pump...

Interesting the reference to "cold knock" - something which i have heard many a D40 (mine included) suffereing from.

So, I'll take the bait and add 300ml to my next fill up - and report back. Mind you, it starts getting expensive doing it EVERY TANK..