2 stroke oil (2SO) as an additive to diesel fuel

[kaanage]

As quite a few us have come to appreciate, 2 stroke oil (2SO) when mixed with diesel fuel at around 200:1 can produce beneficial results. Common findings include quieter running due to lower injector and pump noises, reduced smoke (including before and after results in emissions tests during annual vehicle inspections), cleaner injector nozzles and smoother running.

So here's the new thread for continued discussion on this subject as recommended by one of the moderators.
Link to original closed thread - Adding 2 stroke oil to fuel - Interesting reading!!

Just to kick off with some content, I have been asked why Nth Americans seem to use TCW-3 spec 2 stroke oil in their diesels while european discussions always revolve around JASO FB and FC specification oils.

The only reason that I can find is that the availability of the oils is different in the 2 continents.

Recreational 2 strokes are pretty much banned in North America due to emissions requirements except for outboard boat engines. Since these vent their exhaust into the water, the authorities require the 2 stroke oil to have no metallic content and the current specification that was drawn up for this TCW-3 (which they term "ashless"). This means that TCW-3 grade is by far the most readily available 2 stroke oil in North America so naturally, this is what their diesel owners (those who subscribe to this practice) will buy, use and discuss.
I have also seen discussion of it's use in more dilute form in petrol (gasoline to them) engines for reduction in fuel pump and injector noise.

In Europe, recreational land based 2 stroke engines are the norm and these tend to rev harder and may be subjected to greater loadings than marine 2 stroke engines so the JASO FB, C and D specification oils are required which have small amounts of metals that help in these areas. Since land based 2 stroke engines are more widely used, it follows that the JASO specification oils are more commonly available and it is these oils that are bought, used and discussed (by those diesel owners who subscribe to this practice).

For our diesels, the difference is almost certainly negligible as the speeds and loadings where the 2 stroke oil is providing additional lubrication is not that high vs the requirements of a 2 stroke racing engine. Given this, any of the 4 oil specifications will have the same effect with the proviso that JASO FB specification oil should not be used for engines with DPFs since the higher metallic content of this grade oil may load up the DPF sooner.

JASO FD specification oil is almost never discussed purely due to cost. Its performance is superior in regimes that are not experienced anywhere in the fuel system of a diesel (modern or not)

[CardinalSin]

So would you agree that it's better to use a TC-W3, [semi synthetic, not full synthetic] rather than a Jaso FC with a DPF equipped car?
It's accepted that the 2SO lowers emissions and soot levels from the diesel combustion but I would have thought the ash content of the FC grade, although minimal, would be totally eliminated by using the TC-W3?

Why are there so many threads on the same subject?

[Transporter]

Here is the link to the old thread. Adding 2 stroke oil to fuel - Interesting reading!!

[Ryeman]

Watch you don't get 'cross threaded'! )

[kaanage]

So would you agree that it's better to use a TC-W3, [semi synthetic, not full synthetic] rather than a Jaso FC with a DPF equipped car?
It's accepted that the 2SO lowers emissions and soot levels from the diesel combustion but I would have thought the ash content of the FC grade, although minimal, would be totally eliminated by using the TC-W3?

Why are there so many threads on the same subject?

While I agree with you on the benefits of 2SO as an additive, I wouldn't say that "It's accepted" since at least one moderator here and on other sites do not believe in the concept.

But to answer your question, I would say that, in theory, you're right in that it's better to use a TC-W3 rather than a JASO FC with a DPF equipped car but in practice, the additional ash levels in JASO FC spec 2SO at 200:1 are so low as to have a negligible effect on DPF loading. The reduced soot due to the more complete combustion will mean that the DPF will have less ash in either case - this is how the Cerium and Platinum based additives help maintain DPFs (if it was just the lower light regen temp, then the same soot would still be produced ash would would still accumulate).

By so many threads, do you mean on different forums?

[CardinalSin]

While I agree with you on the benefits of 2SO as an additive, I wouldn't say that "It's accepted" since at least one moderator here and on other sites do not believe in the concept.

But to answer your question, I would say that, in theory, you're right in that it's better to use a TC-W3 rather than a JASO FC with a DPF equipped car but in practice, the additional ash levels in JASO FC spec 2SO at 200:1 are so low as to have a negligible effect on DPF loading. The reduced soot due to the more complete combustion will mean that the DPF will have less ash in either case - this is how the Cerium and Platinum based additives help maintain DPFs (if it was just the lower light regen temp, then the same soot would still be produced ash would would still accumulate).

By so many threads, do you mean on different forums?

Nothing is accepted by 100% of the community, there are always detractors. I mean it's accepted by the majority of those who are interested and widely read on the subject, those that have researched the experiences of others all over the world. Especially the experiences of those in countries that carry out emission tests each year where those emissions are dramatically lower.

The extended regen periods must be caused by the reduced soot and you may well be right that the ash is also reduced by the same factor? In fact when I think about it, the ash must be the residual of the regen and if the regen period is doubled then it's reasonable to expect the DPF to also have double the life before being choked by ash from the fuel.
With only a poxy 3 year warranty I can't think of a better way to extend the life of the engine etc.

By so many threads, I just meant it's been moved around a fair bit in this forum lately.
There are of course, loads of threads on the subject on many other forums which reflect the interest and widespread acceptance from those who want to extend their vehicles life, save money on fuel and reduce environmental emissions.

[Transporter]

The global emissions is a very hot topic these days and I'm sure that if there were any additives in the 2SO that are safe to use they would be already in the diesel blend and the diesel fuel additives.

[kaanage]

I mean it's accepted by the majority of those who are interested and widely read on the subject, those that have researched the experiences of others all over the world. Especially the experiences of those in countries that carry out emission tests each year where those emissions are dramatically lower.

The extended regen periods must be caused by the reduced soot and you may well be right that the ash is also reduced by the same factor? In fact when I think about it, the ash must be the residual of the regen and if the regen period is doubled then it's reasonable to expect the DPF to also have double the life before being choked by ash from the fuel.
With only a poxy 3 year warranty I can't think of a better way to extend the life of the engine etc.

Yes the people in Europe and the UK who report about the reduction in their smoke or haze tests at their annual inspections provide enough weight for me to continue with this practice - this is actually a measurable effect unlike the noise reductions that most others report. And after all, what's in it for them to make stuff up and spend additional money over their base fuel cost for zero benefit?

Yes, DPFs only catch soot particles (which make up the smoke) and it is the non-organic component in these particles that are left behind after the DPF has done a regen that loads it up (these residues being the ash).

If the combustion is improved, then the soot is reduced so the DPF catches less => longer regen intervals and lower loading of the DPF, even if the non-organic content of the soot is very slightly higher (as would be the case with a JASO FC oil).

[brad]

The global emissions is a very hot topic these days and I'm sure that if there were any additives in the 2SO that are safe to use they would be already in the diesel blend and the diesel fuel additives.

How do you know that 2SO isn't part of diesel fuel additives already?

Most fuel injector cleaners have a large percentage (up to 50%) of white spirit (mineral turps). If you told people to pour mineral turps in their fuel tank they would blanche but if you give them a bottle labelled "Fuel Injector Cleaner" they are more amenable to the idea.

Personally, I think it boils down to those willing to experiment & those that aren't.

I find it amusing that you say that you always follow the instructions but don't the vehicle manufacturers say that additives aren't necessary? Therefore your use of chemicals labelled "diesel fuel additive" goes against the manufacturers instructions.


BTW: On Friday I put 50ml of the 10 year old Stihl / Castrol 2SO was sitting on the shelf at home & then added 1 litre of 50:1 premix because it was looking a bit stale. I figure thats about 1000:1 ratio in my petrol. I've thought nothing of it until this discussion.
Here's an interesting observation: Usually in the commute from home to where the motoraway starts (5km) I think I'm going well if the avg economy slips below 10L/100km. The last 2 days it's been below 9L/100km. So, 2 stroke fuel / better run of lights / less traffic overall / ideal air temperature (24c)? Who knows. It will be interesting to see how it goes long term.

[CardinalSin]

Yes the people in Europe and the UK who report about the reduction in their smoke or haze tests at their annual inspections provide enough weight for me to continue with this practice - this is actually a measurable effect unlike the noise reductions that most others report. And after all, what's in it for them to make stuff up and spend additional money over their base fuel cost for zero benefit?

Yes, DPFs only catch soot particles (which make up the smoke) and it is the non-organic component in these particles that are left behind after the DPF has done a regen that loads it up (these residues being the ash).

If the combustion is improved, then the soot is reduced so the DPF catches less => longer regen intervals and lower loading of the DPF, even if the non-organic content of the soot is very slightly higher (as would be the case with a JASO FC oil).

The reduction in engine noise could be measured in decibels if you had one of those meters. Most people report it's quieter and it's logical and reasonable to assume if it was louder they would say 'it's louder' and once again they have no motive to say it's quieter if it's actually louder or the same. My last vehicle was a good example of that, it was much quieter and smoother, an unmistakable difference.

As was the fuel consumption, since I keep records the 5% improvement was obvious and immediate.