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

[Amalgam]

Thanks for that informative post.

That's an decrease in fuel consumption of almost 12% overall and almost 18% for the return trip! (that's by dividing the new consumption vs the old - I could inflate those numbers by working the figures the other way) While I am an advocate of using 2 stroke oil as a diesel additive, there must be some other factor at play that helped out on the return trip to produce such a stunning improvement. Was there a tail wind most of the way coming back?

I assume your car has a 70l fuel tank - could you also tell us what sort of car and engine is it and how much mileage has it done? And what was the distance of the trip down to Margaret River?

Even the 6% decrease on the trip down is impressive enough for me to want to run it for a couple more tanks, if only to see if there is an improvement in the "normal" driving fuel consumption. Plus the subjective noted gains in the behaviour of the engine are worthwhile too.

But if you decide not to use it in the next fill, it would be interesting to know if you feel any immediate difference once your car is running straight diesel again.

All the variables, environmental and vehicle related were similar ie there was no howling headwind or tailwind, the load was the same except for the fuel as we did not top up and the gauge was just under half when we returned home, the route was exactly the same.

The distance between my house and the hotel was 260km and the total distance travel inclusive of side trips in the region was approx 700km.

The car is a MY12 Passat 125TDI with 36000kms. Tyre pressure was set to 38psi when I topped up.

From my post in Christmas 2012 I was achieving high 5L/100kms when the car was 5000kms old. I am therefore guessing that the 2SO acted as a "cleaner" removing deposits from the injectors and other parts to return the engine to "as new". If this is the case, it is interesting to note that I did not achieve similar results with either LiquiMoly or Penrite DPF/Injector additives.

I would be grateful if those with a more indepth understanding chime in.

[CardinalSin]

That's quite a result!

From the balance of the reports so far about a 5% saving in economy is the average. Was that calculated at the pump or from the readout?
Not that it makes any difference because it's the comparison that counts. I see your car is rated at 5.7L/100km and you averaged 5.9L/100km over the trip. It's interesting that your fuel consumption has increased from 5,000km to 30,000km and your suggestion that the 2SO has cleaned the engine sounds the only viable explanation to account for the over 10% improvement in economy.
You could narrow it down to the injectors being the most likely benefactors.

You mentioned the engine was quieter. Was it quieter at 5,000km and then got progressively louder, that's a hard one to be aware of.
I'm just wondering if it was quieter and now it's back the way it was, perhaps even quieter?

With that fuel consumption you could use the same way to calculate how much 2SO to use as I do. Set the trip at each fill up and just add 1/3 of the km in ml. 600km = 200ml It should be 180ml at 600km for yours but it's near enough.

Can you tell when your DPF is doing its thing? I can honestly say that I never been aware of that which is strange because I listen out for anything out of the ordinary, probably a habit from driving so many old bombs in my youth.

Thanks for the feedback, especially with such positive results. As for using it once in a while as an additive to clean the system or whether to add it at every fill is a decision you have to make. Once you stop, if it returns to it's previous diesel clatter, you might use it again just to shut it up and enjoy the smoother, livelier engine. Then there's the fuel consumption but for me, the biggest incentive is the thought that it's extending the life of not only the engine but the fuel system and even the exhaust components.

[Ryeman]

If it was a nice quiet trip both ways could it be that a trip south in warm temps and a northerly was followed by a dry front with a southerly wind coming home.

[kaanage]

Looking at the Mean Sea-Level Pressure Analysis for the 14th of Feb on the Bureau of Meteorology site suggests that for that region there was southwesterly wind for the whole morning from the high pressure system off the coast (after the cold front that came across around midnight) switching to a southerly as the high pressure system moved further across.

Looking at Cunderdin and Busselton Airport's observations for the confirm this

So most likely headwind/crosswind on the way down, tailwind/crosswind on the way back.

Locals would be best to confirm or deny this

Cleaning off the carbon deposits on the injectors and from the head and piston crown would seem to be the most likely cause for the majority of the economy improvement with some improvement also due to the engine running in more.

Thanks for the additional information, Amalgam

[Amalgam]

Was that calculated at the pump or from the readout?
Not that it makes any difference because it's the comparison that counts.

All data was from the MFD for all my trips.

the engine was quieter. Was it quieter at 5,000km and then got progressively louder, that's a hard one to be aware of.
I'm just wondering if it was quieter and now it's back the way it was, perhaps even quieter?

IIRC the engine is now as quiet or quieter when compared to new. I was 'blending' my own B5 with 7L of Gull B20 and topping up with Ultimate/Vortex. Studies show that B5 and 1:200 2SO have similar lubricity.

Can you tell when your DPF is doing its thing? I can honestly say that I never been aware of that which is strange because I listen out for anything out of the ordinary, probably a habit from driving so many old bombs in my youth.

I am only aware that I have interrupted an active DPF regen when the radiator fan continues to run on at high speed after being switched off or there is an increase in the MFD oil temp when driving.

for using it once in a while as an additive to clean the system or whether to add it at every fill is a decision you have to make. Once you stop, if it returns to it's previous diesel clatter, you might use it again just to shut it up and enjoy the smoother, livelier engine. Then there's the fuel consumption but for me, the biggest incentive is the thought that it's extending the life of not only the engine but the fuel system and even the exhaust components.

Yes I am considering all of the above. I am just gob smacked by the numbers.

[Amalgam]

Cleaning off the carbon deposits on the injectors and from the head and piston crown would seem to be the most likely cause for the majority of the economy improvement with some improvement also due to the engine running in more.

My thoughts exactly.

[CardinalSin]

Looking at the Mean Sea-Level Pressure Analysis for the 14th of Feb on the Bureau of Meteorology site suggests that for that region there was southwesterly wind for the whole morning from the high pressure system off the coast (after the cold front that came across around midnight) switching to a southerly as the high pressure system moved further across.

Looking at Cunderdin and Busselton Airport's observations for the confirm this

So most likely headwind/crosswind on the way down, tailwind/crosswind on the way back.

Locals would be best to confirm or deny this

Cleaning off the carbon deposits on the injectors and from the head and piston crown would seem to be the most likely cause for the majority of the economy improvement with some improvement also due to the engine running in more.

Thanks for the additional information, Amalgam

I live in the Margaret River region and we've had SE winds lately, bringing the smoke across from the fires down at Northcliffe.
So the headwind coming and tailwind leaving fits perfectly. no wind from the north for at least a week.
It swings across from the SW later, as the sea breeze comes in.

[CardinalSin]

Amalgam,

I tried to post as you did but it turned to mud so it's just the replies below and I hope it makes sense?

That is what I expected but good that you confirm. It's certainly what I have found.

So having tried bio diesel blending and knowing the lubricity is similar, how do they compare in practice?

I did get that once when I stopped. The fan was going flat out, the temp read normal so I walked to the front and had a look under the engine expecting to see coolant but there was nothing, then the fan stopped. Good to know.

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.

I parked next to a Passat Wagon this afternoon and had a good look. It's a classy car. With that extra grunt from the higher rated engine and 100kg lighter than my Yeti it must be a good driver's car.

[kaanage]

IIRC the engine is now as quiet or quieter when compared to new. I was 'blending' my own B5 with 7L of Gull B20 and topping up with Ultimate/Vortex. Studies show that B5 and 1:200 2SO have similar lubricity.

So are you saying that your Passat runs quieter and more smoothly with 1:200 2 stroke oil than with the "B5"?
That would mean it was definitely more than the lubrication effect of the 2 stroke oil that was causing the improvements.

Was the engine better with the "B5" than with straight diesel?

Sorry for all the questions but you've tried more things than I have and the direct experiences are the most valuable ones.

[Amalgam]

So are you saying that your Passat runs quieter and more smoothly with 1:200 2 stroke oil than with the "B5"?
That would mean it was definitely more than the lubrication effect of the 2 stroke oil that was causing the improvements.

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

Was the engine better with the "B5" than with straight diesel?

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