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

[brad]

This thread could be updated to fuel instead of diesel?
Those economy figures are fantastic for a petrol engine, especially if you are still running the part ethanol fuel. Ethanol has a lower energy content and relies on high advance to take advantage of it's high octane rating.

Nah, I gave up on ethanol experiments last June. The extra torque over a larger range (it came on earlier & quicker & was probably good for 30Nm - so I was pushing 350-370) was nice but you could tell it was ovefueling and the ECU / O2 sensors didn't have enough range to deal with the figures coming down the tailpipe so once in a blue moon you'd get a CEL that the readings were out of range. This would have been on about E20-E30 at 102-105ron. They fuel usage would skyrocket as expected but then would stay high for a few tanks when you reverted back to pure 98ron.

Physical signs that it was rich / oversooting were when I pulled out the O2 sensor near the #2 cat and it was quite coated. I burned it all clean with the blow torch I use for putting the toffee crust on a Creme Brulee and then cleaned the inner section where the sensor is with solvent.

At the moment it's like "I'm losing weight" and not knowing if it's because you have cancer or leading a healthy lifestyle.

[brad]

So, brad, are you running at 500:1 with petrol, like the guys in the US forums?

Somewhere between 800:1 & 1000:1 IIRC. I kind of stuffed up the calculation but on the conservative side. I'll stick around 1000:1 for a tank or two more then try closer to 500:1 and see what happens.

Interesting stuff but I'd love to know why

[gldgti]

I bought a 5L bottle of GW TC-W3 synthetic 2SO yesterday at SCA for $29. I have organised a 500ml bottle to keep in the boot, and I'll just put half in every fill up for a while and report back my results.

The last 2 tanks have had no 2SO and I noticed the engine noise (diesel ignition knock) is louder again for sure - and starting is back to pre 2SO amounts of cranking (wont always catch on the first crank).

Everyone keep in mind that my audi is a VP pump diesel with mechanical fuel injectors (spring loaded), and by common rail standards not high pressure injection.

[CardinalSin]

I bought a 5L bottle of GW TC-W3 synthetic 2SO yesterday at SCA for $29. I have organised a 500ml bottle to keep in the boot, and I'll just put half in every fill up for a while and report back my results.

The last 2 tanks have had no 2SO and I noticed the engine noise (diesel ignition knock) is louder again for sure - and starting is back to pre 2SO amounts of cranking (wont always catch on the first crank).

Everyone keep in mind that my audi is a VP pump diesel with mechanical fuel injectors (spring loaded), and by common rail standards not high pressure injection.

Don't forget that JASO FC mineral is the best grade to use. Fully synthetic does not burn completely in a diesel and TC-W3 has been observed not mixing well with diesel. JASO FC bonds with diesel and burns completely.

Glad to see you got some real results. It's irritating, to say the least, to be told it's a placebo effect and therefore all in your head, an illusion.

[brad]

If I could work out how to insert an exel spreadsheet into a forum post I'd show you my fuel spreadsheet for the last 10 fills (even the last 7 years), 3 have been on 2SO and there's a definate improvement considering I'm driving faster (M5 is back to 100kmh and as 3 lanes).

[CardinalSin]

Brad,

Can you take a screen shot and copy and paste that?

[gldgti]

Heh, well perhaps I'll keep the synthetic for the boat and get some mineral stuff then.

[CardinalSin]

I did exactly the same thing and my 4L of Nulon super dooper fully synthetic TC-W3 is sitting in the garage ready to give the chainsaw a treat or to use if I ever get that tinny.

[kaanage]

I haven't seen any issues with the Shell Nautilus TCW-3 mixing with diesel - I have it mixed in a yellow plastic jerry can when I go to track days and I see no signs of separation. I don't think it's pricey enough to be fully synthetic

[CardinalSin]

I can't see anything to say it's fully synthetic or even part synthetic.
TC-W3 is often used in the US in diesel by preference, in the forums that i've read but in Europe it gets the thumbs down. It might also be that it's lower in detergents for environmental reasons and can't clean as effectively? Maybe it's harder to get in Europe?
I decided to play safe and go back to low ash FC.

[kaanage]

I still stand by what I posted earlier - the preference is Europe vs North America is purely due to purchasing availability. Our diesels don't rev like a high performance 2 stroke engine so TCW-3 vs JASO FC make no difference from our point of view

[CardinalSin]

I still stand by what I posted earlier - the preference is Europe vs North America is purely due to purchasing availability. Our diesels don't rev like a high performance 2 stroke engine so TCW-3 vs JASO FC make no difference from our point of view

Speak for yourself, my diesel has hit 5,000rpm several times.

I'm sure you're right and it doesn't matter.

[kaanage]

I'm talking about 9000 rpm onwards. 5000 rpm is nothing

[CardinalSin]

5,000rpm is close to the max rpm for most of the outboard motors that TC-W3 was designed for and many of those will specify fully synthetic, mainly to allow minimal dosage.
I've lost track of what this was about?

[kaanage]

TCW-3 vs JASO FC suitability for diesels as a lubricity and general fuel treatment additive.

You are entirely correct that the fully and semi synthetic 2 stroke oils are formulated to allow higher dilutions than fully mineral (and castor!) oils, which should slightly reduce the drag from the oil film and also burn slightly cleaner. So goes the theory anyway. When I raced 2 stroke GP bikes, most of us tried the various types of oil and we all came to the same basic conclusion that the synthetic content did allow the oil to be diluted about 30% more vs traditional oils but no more for safe operation.

I still don't see the reasoning behind fully synthetic 2 stroke oils being unsuited for diesels vs mineral oils beyond their greater cost. The burn characteristics are not different enough to be worth mentioning. The higher detergent content of JASO FD specification oils may have a slight burn effect but the cost is also the main reason it's not recommended.

Just for interest
Here is the JASO application file for oil manufacturers to submit for classification - it includes the various requirements that must be met http://www.jalos.or.jp/onfile/pdf/2T_EV0412.pdf
and here is the definition of the lubricity portion of the test JASOM340-92lubricity.pdf
Here is the certification manual for TCW-3 https://www.nmma.org/assets/cabinets...anual-4-08.pdf

You will see that JASO tests to 4000rpm while TCW-3 tests to 5500rpm

I'm happy with a 2 stroke oil that meets either specification