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

[Ryeman]

At least in the Southern Hemisphere you can get a tailwind both ways if a front goes through after you have arrived at a SW destination.
I observed the irritating opposite when I used to commute to the north on a day trip.....howling hot headwind then cold heavy headwind.......grrrrrr

[Amalgam]

Amalgam,

It is strange. 2SO punches way above it's weight considering the tiny amount being used. When the inevitable question gets asked on a regular basis, "if it's so good why don't they add it at the refinery?", you have to wonder why they don't. It's a match made in heaven.

Unfortunately it is always about profit. If they can save 0.5 cents/litre that will add millions to their bottom line.

A B5 diesel, which all diesel engines can cope with, would provide quieter smoother engines, act as a injector cleaner and is more eco sensitive would solve a lot of our issues. As you may be aware B5 is mandated in the EU.

[kaanage]

Gull stopped retailing B20 6-12 months ago, so my comments are all from memory. I believe that B5 and 1:200 2SO are comparable in their noise reduction. Here is a link to a lubricity study comparing B5 and 2SO

http://www.natbiogroup.com/docs/educ...%20results.pdf

I always felt that B5 was quieter and smoother than straight diesel, even Ultimate/Vortex.

Ah yes, the old Spicer test - I wish there was an update on this since it was done back in 2007.

B5 should be a much better lubrication enhancer than anything else although that test was done with straight diesel without the additives that all the brands need to add to bring the wear scar level down to Australian requirements. They really should have also tested with a pump fuel just to see how much additional effect the different additives had over the regular additives (although that would vary with brand and country, it would still be indicative).

Still, from your experience, it all points to 2 stroke oil having a pronounced cleaning effect in the combustion chamber, whatever the mechanism.

As you may be aware B5 is mandated in the EU.

I'm pretty sure this was more for political reasons (ie greenyness) than anything else.

[gldgti]

I'm not so sure about the cleaning effect conclusion. It could easily be an effect on the atomisation or flame front propagation - who knows?
Even the pictures of the fuel injectors posted a few pages back are at best circumstantial. You would need much more tightly controlled experimental conditions to draw firm conclusions.

From my own experience, bio is smoother and quieter than 2so.

[kaanage]

Weren't you running B100, though? That's a fuel replacement rather than using an additive (like running 2 stroke oil straight, which I've heard has been done but not by anyone I personally know).
Amalgam was only running a B5 blend mainly for the lubricity enhancement from what I can see.

Circumstantial evidence the injector pictures may be but it does point towards cleaner running. I have seen many more comparative pictures of injectors and cylinder heads on other sites which strongly supports the cleaning hypothesis, whatever the mechanism (but not being mine, I won't post any more links to them given the rules for this thread about speculation and nth degree experience where n > 1)

[gldgti]

I suppose your observation is partly the reason for my reservation. I know that using B100 makes for a significant difference in the running characteristics of a diesel engine - about a 2-5% worsening in fuel economy (measured), noticably less ignition noise (when warm), reduction in soot and an invisible increase in NOx (due to excess oxygen) - among other minor things.

I also know that using a blend of Bio and mineral diesel can result in observing some reduction in the ignition noise, smoothness etc.

The thing is that Biodiesel is chemically quite different from mineral diesel - sure they are both long chain hydrocarbons, but bio has a lot of OH group's and various aromatics that arent present in mineral diesel. Bio is a fuel made of methyl esters - its edible, for crying out loud (not that it tastes any good!).

And yet, the net effect is not a night and day difference in engine performance - its significant, but its not miraculous.

Then theres the aforementioned theory of a healthy improvement in fuel economy with just the addition of a few percent 2SO to regular diesel...

All this to say nothing really.... just wanting to explain my, lets say, healthy scepticism.

[Amalgam]

I also know that using a blend of Bio and mineral diesel can result in observing some reduction in the ignition noise, smoothness etc.

Agreed

And yet, the net effect is not a night and day difference in engine performance - its significant, but its not miraculous.

Agreed

Then theres the aforementioned theory of a healthy improvement in fuel economy with just the addition of a few percent 2SO to regular diesel...

I am only providing the conditions and the MFD reading from my last trip. I am unsure to the reason why there is such as dramatic improvement in fuel economy. My guess is that the 2SO is acting as some sort of 'cleaner' returning the engine to 'as new' condition and the resultant L/100km figures are similar to when the car was 5000km old. I am not suggesting that 2SO will improve fuel economy any further or that it will improve the combustion process or increase power.

Nobody is more surprised by the figures than me.

All this to say nothing really.... just wanting to explain my, lets say, healthy scepticism.

Agreed. An inquiring and open mind is most important.

As previously, I would be most grateful if a member of this forum could provide a definitive reason.

[Transporter]

I am unsure to the reason why there is such as dramatic improvement in fuel economy.

...or there was an active regeneration during the first trip and no regeneration during the second trip.

[brad]

I know I have a petrol engine but I do the same 45km trip (90km total) every work day. My economy at the end of the trip can vary by about 15% for what appears to be the same trip. Add rain, significant headwinds or traffic issues and it can vary 30%.

Rain is the one that blows me away - a damp road (no significant standing water) will cost me 1L/100km.

[kaanage]

...or there was an active regeneration during the first trip and no regeneration during the second trip.

It would have to be multiple regenerations to make such massive difference though, given the length of the journey. And Penrite DPF cleaner was used on the first trip so the return should have been better than the outbound leg.

I know I have a petrol engine but I do the same 45km trip (90km total) every work day. My economy at the end of the trip can vary by about 15% for what appears to be the same trip. Add rain, significant headwinds or traffic issues and it can vary 30%.

Rain is the one that blows me away - a damp road (no significant standing water) will cost me 1L/100km.

That's why being a long highway run (with little traffic I assume, given Amalgam's statements) is a much better comparison to urban runs - I assume that a fair proportion of your daily commute is urban, brad (please correct me if this is not so)