Two stroke experiment

[defever]

Hello 1.9 TDi drivers,

I've been experimenting with different fuel quality for the last few months (thread link to my observations: Fuel and Italian Tune Up! (http://www.vwaudiforum.co.uk/forum/showthread.php/170960-Fuel-and-Italian-Tune-Up!)) and "two stroke oil" was mentioned.

WARNING: Yes, this is another "two stroke oil in diesel fuel" thread...


I've heard of this too, so I quickly searched about it just now. LOTS OF INFO about this on virtually every car forum (and they are not short threads!). The effect, whether it is placebo / shameless publicity / genuine evidence, overwhelmingly one sided in favour of adding 2 stroke oil.

But not any 2 stroke oil, apparently. Ones I heard was to use:
Mineral, low ash 2 stroke oil
Ratio of 200:1 - 250:1
(i.e. 250-300ml of 2stroke in a 60L full tank diesel)


Mineral is the key. Not full-synthetic. Semi-synthetic does work, but mineral is recommended, apparently.
Also, "low" ash is important, as you wouldn't want a type of oil leaving large amount of ash when burnt in the combustion chamber.

The consensus on benefits are:

Quieter engine noise
Better response


Which is quite a subjective marker.

Less mentioned but claimed benefits are:

lubricates everything in the fuel system
cleans fuel injectors, valves, turbo, DPF...


How have the people who claim these measured the "cleanness"? I don't know.

This is what I found so far.

I never tried it, and I'm a bit apprehensive about it, but I might try it.

So, being an impulsive individual, I decided to try it.

I bought a litre of two stroke oil from Halfords (low ash and mineral) and poured around 200ml to 80% full tank and drove 80miles.

Immediate observation: engine noise is sooooo much quieter and smoother at idle. Definitely a massive change!


But that was it, really.


No other change that I noticed whilst driving 80 miles.

I have about 800ml of two stroke left to use so I will experiment with it for the next couple of month and I'll report my observation here!

[defever]

A quick update...

I've done about 1/2tank since putting 2 stroke oil. The engine noise has returned to pretty much normal (pre-2 stroke).
Maybe it's still a bit quieter at idle, but not as quiet as I felt immediately after when the 2 stroke was put in.

Not much difference that I felt on MPG or acceleration or throttle response...

This got me thinking.
The fuel is BP Ultimate.
I'm wondering if the fuel "additive" within BP Ultimate already includes a substance similar to 2 stroke oil?!
Maybe I'm overdosing it?!
Or maybe I'm going over the top with it all?!

[adamss24]

Add the whole bottle ! The 1.9 tdi is not the smoothest or quietest engine VAG group made but it's one of the most ecconomical they made ! Watch the mpg go up a little, more so in the summer when warm weather returns and summer diesel is about ! Stop using BP ultimate and switch to regular Shell diesel, you will feel the difference !

[adamss24]

Also you're peeing in the wind expecting to feel any more power from the engine with just a bit of 2 stroke oil added to the tank ! Most likely the nozzles and pump are worn and the ECU is crude by modern standards but the engine has the best BFC to date, better than even the latest CR engines !

[defever]

Thanks adamss24,

I'm not convinced a whole 1 litre bottle of two stroke oil in one tank of fuel is wise. What I read is 1:200-250 ratio; adding a 1L to a tank is 1:60 ratio. It might be okay for an old diesel engine (before mid-90s), but I they can run on anything anyways.

I've been using BP Ultimate because it produces the highest combined MPG on my car. I agree with Shell fuel; In my experience, V Power is the best (by 1 MPG). But my nearest Shell station is 20miles and it doesn't make sense to do 40miles round journey for 1mpg gain.

I don't think the two stroke oil claims to directly impact on MPG; it's been known to reduce engine noise, "better response" and lubrication to the fuel system. So I agree that if I want to increase my mpg, then two stroke oil isn't the thing to do.

Continuing with the observation...

[Gazwould]

It does but only a few mpg .

Increases Cetane number also .


Effects of 2t oil added to diesel cars.

Due to the pollution control measures of the EC diesel-oil is nearly sulphur free and contains up to 5% of bio-diesel. Sulphur has the property to grease the high pressure injection pump and the injectors. Without sulphur, the reduced greasing property of the new diesel has already shown negative impacts on the long-term stability of the injectors and the high pressure pump. The pump manufacturers have tried to react by lining the moving parts of the pumps with Teflon or other suitable material. However, the long term stability is still not achieved as with the old (sulphur contained) diesel.
The engine-research centre of a well-known German car manufacturer has conducted some long term tests of diesel additives to find out whether any one of them will have an impact on the long term reliability of the diesel engine components. This introduction to explain were my information comes from.
The results of this research: any diesel additive of any manufacturer presently on the market is not worth the money!
BUT: 2-stroke oil, which we use in our motor saws, lawn mower or in 2-stroke motor engines has shown to have an extreme positive impact on diesel engines, if such 2-stroke oil is added to the diesel in a homeopathic doses of 1:200. In practical terms: 0,300 litre of 2-stroke oil into the 70l diesel tank. The 2-stroke oil will be absorbed by the diesel (emulsion) and grease every moving part of the high pressure pump and the injectors.
Besides this, the 2-stroke oil will keep the diesel engine clean, as it burns cleaner as the diesel itself.
In other words, the 2-stroke oil has a much lower ash-content as diesel, when burned. This proven fact delays the DPF (diesel particulate (soot) filter) to clog, and the "burn free" process of the DPF will be much less.
More information: in Germany we have to present our cars every 2 years to the TUV -Technical Supervision Organisation - who will check, amongst others, the pollution of petrol and diesel engines.
The measured cloud-factor of a diesel engine without use of 2-stroke oil has been 0,95.
The same factor with the use of 2-stroke oil has been 0,47 - reduction of nearly half of the soot particles.
Besides this, the use of 2-stroke oil in the diesel will increase the mileage by 3-5%.

[defever]

Thanks very much Gazwould, very interesting.

If 2 stroke is so beneficial to diesel engines, why is this still a "secret" to the general public and why haven't the industry try to make money out of it already?
They could easily market 2-stroke oil as "diesel additive" and sell a 500ml bottle for £10, just like any other additives, and actually make a difference to the engine?

I filled up my tank this evening; my MPG for the previous tank was 51.53mpg. This is one of the lowest I've done in the last 9months. However, I had more town driving and less motorway driving than usual (so I try to justify the low mpg).

What I noticed is that the mpg calculation on DIS was 4.5mpg off. With BP Ultimate, it's usually 5.5mpg off. So there's 1mpg improvement.

I added anther 250ml of two stroke to a tankful of BP Ultimate again. I'm expecting more of the usual driving (more motorway, less town) so let's see how the engine behaves in terms of mpg, noise and other variables that two strokes are claiming to influence.

[defever]

A fuel refill update.

I've done a tankful of 90% motorway speed and 10% stop start town driving.
MPG was 56.76, DIS showed 61.6 (4.9MPG offset).

This is what I expect from BP Ultimate, regardless of adding two stroke oil or not.
The MPG is consistent with previous records.
Still no difference on throttle response or engine noise.
I'm not seeing anything different with adding 250ml of two stroke oil on my AFN, apart from the quietness I noticed when I first added two stroke.

I wonder if adding two stroke on premium diesel is redundant.
So I filled with an ordinary supermarket diesel and another 250ml of two stroke oil.
I'll see how it has an effect on the engine with a supermarket diesel.

[TDI JIM]

I have also used 2 stroke oil in my 110 tdi AHF engined Seat leon... I stopped using it 5 years ago, as I didn't really see any benefit after 10,000 miles

The best jump in MPG I had seen in 100k that I have driven the car - Even with the injectors/full custom remap to 155bhp was altering the SOI. Using VCDS and advancing the Start Of Injection by +3 degrees has increased the economy by an additional 10-15%. It runs superbly, pulls like an absolute train and with almost no smoke. With this little tweak, I have to try very, very hard not to get 600 miles from a full tank. It is my commuting car and does 100 miles a day and the result has saved me a fortune as I did this 2 years ago...

[defever]

Another update.

I put my last 250ml of two stroke oil in the tank and done 650+miles with about 1/4 tank to go.

Looking back, maybe the engine noise has gone down overall. But I'm sceptical as to if this is a placebo effect and whether it did actually reduce the overall engine noise.
Throttle response: again maybe a bit better but perhaps placebo.
MPG: no change.
Smoke: no change. I had no smoke problem before I started adding two stroke oil so I would never know.

So I'm going to stop adding two stroke for a while and see if there's any change.

[defever]

Another update; maybe a final one.

I had ordinary supermarket fuel for the last two tankful with two stroke oil (250ml per tankful).

Overall observation, the general engine noise MIGHT have been less compared to pre-two stroke experiment but the difference is so marginal (and subjective), I put it down to placebo effect.
No other difference that I felt clearly; no change in throttle response or MPG.

I did the mpg calculation for the last two tanks. The offset of DIS vs actual MPG calculation were:

6.2MPG: same as I would expect from a supermarket fuel without adding two stroke
5.9MPG: again, as I expect from a supermarket fuel without two stroke.


I'm still convinced that adding two stroke oil MAY have a function of "lubricating" the fuel system, but I will never know if it actually does unless I do pre- post- inspection of inside the fuel injectors. But, that initial reduction in engine noise was definitely recognisable, so maybe it doesn't need to be added every tankful, but perhaps a dose from time to time.

Cost-wise, 1L of two stroke oil is £6.00 from Halfords which equates to £1.50 per dose (250ml). Doesn't change my MPG at all.
I know that BP Ultimate is more than supermarket fuel, but factoring in the higher MPG result, the difference is only £2.15 more for BP Ultimate.
I think I can live with 65p more per tank by using BP Ultimate and not having to mess with pouring two stroke into the tank when I fill up.

So, I'm going to conclude that:

Adding two stroke (250ml per 60L tankful) on my engine only had a subjectively perceived difference on engine noise at the initial dose (which seemed to diminish after 1/2 tank).
A dose of two stroke oil from time to time might still be a good idea, instead of every tankful.
I'm going to stick with BP Ultimate or Shell V-Power (when I can find Shell station)
I'm quite geeky


It was definitely an (unscientific) experiment worth carrying out to see if two stroke oil had any positive effect on my car.

[Gazwould]

Always subjective .

JASO FB spec.

Asda 1L is £5 and on offer I've got Carlube 1L for £4 .

Better is £3.59 per 1L if 5L Comma is purchased .

COMMA 2 STROKE MINERAL ENGINE OIL 5L LITRES TST5L | eBay (http://m.ebay.co.uk/itm/COMMA-2-STROKE-MINERAL-ENGINE-OIL-5L-LITRES-TST5L-/182017087134?nav=SEARCH)

[defever]

Gazwould,

I'd be keen on learning tricks and tips on how to maintain my car as long as possible and improve efficiency. It seems to me, with my car, that the benefit of adding two stroke oil is marginal and not worth the effort.
I'm not generalising that it's the same with every AFN engine still out there, though. I understand every engine behaves and responds differently. So I wanted to try it and found that it has little effect.

Do you still add two stroke on yours? Is it AFN or one of the PD engines that you have? chip tuned?

[Gazwould]

PD AVF remapped to 180 bhp .

[TDI JIM]

I would trust your ears, they are right that the engine sounds smoother. I found the biggest sonic change was starting from cold mid winter, the diesel 'crackle' is noticeably softened.

If your wanting to squeeze some more MPG's from fuel additives, you might want to try some 2-EHN next.
Its a cetane booster added to derv and sold as Ultimate or V-Power etc. Buy it online pure in 1L containers & store out of sunlight as it will degrade. I add 25-50ml to my supermarket diesel. But, I don't do it too much....I end up enjoying the added zing a little more than i should!

[Gazwould]

I saw a study into cetane boosters , loads of makes, some did, some didn't , 2 Stroke did !

[TDI JIM]

If you wish to investigate -
The two I have tried for the last year are Millers Ecomax and 99.5% pure 2-EHN from Trinity Chemicals. Both give results. The pure is better value as it's almost the same price as the Millers for twice as much.
The Millers is supposed to have lubricity enhancers so that goes in my other car, which is common rail, and the 2-EHN goes in the Leon.

[soobusdriver]

Just read this experiment here based in South Africa from March 2015 - 2-Stroke Oil In Diesel – A Technical Study (http://www.fuelexpert.co.za/2-stroke-oil-in-diesel-technical-study.php)
It mentions injector fouling by zinc due to using 2 stroke oil...

[Gazwould]

Obviously , that's why all the 2 Strokers breakdown with fouled injectors , NOT .

The only time I ever see missfires in my type of engine is a injector loom breaking down with heat and age , usually 200k+ or injector duration not achieved through a worn cam lobe because of poor servicing and or non PD oil being used.

Plus we use JASO FB and not FC .

[TDI JIM]

No long term ill effects here either.

[defever]

Just read this experiment here based in South Africa from March 2015 - 2-Stroke Oil In Diesel – A Technical Study (http://www.fuelexpert.co.za/2-stroke-oil-in-diesel-technical-study.php)
It mentions injector fouling by zinc due to using 2 stroke oil...

I briefly read this article when I was first interested in adding two stroke oil.

Unsurprisingly and likely a biased paper, it's poorly written "scientific" abstract; where's the statistical analysis to show a significant effect of adding two stroke oil? They say "significant fouling" but the report failed to show at what significant level (p-level) the fouling was detected.

So, I'd ignore that report, it's not a good reported experiment.

[defever]

Gazwould and TDI Jim,

Interesting points made re: JASO FB and 2-EHN. I don't remember the specification of Halfords' twos stroke. 5L Coma doesn't seem to specify JASO FB either, just says low ash mineral.
I might look into 2-EHN but it looks like a minefield and I don't have much time at the moment to get geeky about it.

But I'll revisit adding two stroke oil and maybe 2-EHN in near future once I have few tanks of just BP Ultimate vs supermarket diesel.

Thanks all for your comments! Very educative, indeed.

[Gazwould]

There's your FB spec .

Two Wheel 2 Stroke : 2 & 4 Stroke Oils : Products Guide : Comma Oil & Chemicals Ltd. (http://www.commaoil.com/passenger-vehicles/products/view/267)

[JMR1]

Just to add my 2t experience. My car is an 2003 Audi A6, C5, 1.9 AVF Diesel. I Was having intermittent limp home mode problem, especially when towing, and considering having turbo replacement, so decided to try the two stroke treatment. 300 Ml to full tank. Result? No more limp or lag problems, car pulls like a train, and is much smoother to drive. I use it now as standard when refilling, and so far no problems what so ever.:)

[Gazwould]

Great news, but surely that limp mode induced under load is a sticking vnt causing over boost limp mode and requires the famous Mr Muscle treatment or a strip down and clean of the turbo .

[defever]

A little update.

Since my last post, I've added approx 250ml + 30-50ml 2-EHN for the last two tanks with supermarket standard diesel and this was the last reading from this morning's fill up:

Supermarket standard diesel (£1.049/L) with the mixture: 60.4mpg (DIS discrepancy 4.8mpg)

It was 90% motorway (trip odometer: 810miles), hence the impressive mpg. Comparative readings I've been taking for the last year or so are:

Pre-limp mode supermarket standard diesel: approx. 54mpg (DIS discrepancy approx 6.7mpg)
Normal BP diesel (108.9p/L): 52mpg (DIS discrepancy 6.5mpg)
BP Ultimate (118.9p/L): 55mpg (DIS discrepancy 5.5mpg)
Shell V Power (118.9p/L): 56mpg (DIS discrepancy 4.1mpg)
(Fuel and Italian Tune Up! (http://www.vwaudiforum.co.uk/forum/showthread.php/170960-Fuel-and-Italian-Tune-Up!))

Adding a mixture of two stroke oil and 2-EHN seems to be the next best thing to Shell's V Power.

I bought 1L of 2-EHN for £10.99 and 5L Comma two stroke oil for £17.95. The 300ml mixture only comes to £1.45 per tank. That's cheaper than the premium fuel and the mixture seems to help with MPG much better than BP Ultimate on its own (adding 250ml of 2SO didn't really help much with BP Ultimate).

I'm going to add the mixture to couple more refills and see what the mpg comes out. Quite interesting!

[Gazwould]

Great stuff defever , keeping an open mind , a few variables to consider are temperatures , dervs love the heat , but not too much as intercooler etc heat soak, quicker warm up times for better mpg , usually around 18°C is mpg optimal .

The whole 2 stroke and 2 EHN thing is about , lubrication , detergents , dispersants and combustion . The quietning of the engine when using these products particularly when cold comes from reduced ignition delay , more delay from lesser cetane derv and more diesel 'knock' , more knock from cold start up as derv is even more stubborn to compression ignition .

Ever heard of taxi drivers using a splash of petrol in winter ?

EHN cetane booster will work as it reduces the ignition delay.
So does 2Stroke , but I don't know what chemical in it is responsible .

It's not rocket science as to improve diesel combustion through reducing ignition delay you must have something with it that is more combustable , it ignites and the diesel combustion follows , be it , petrol, kerosene , or ethylhexyl nitrate .

[TDI JIM]

Great to hear some positive feedback..Have just finished the Millers I had and I am looking for a replacement additive for the C.R. V6 TDI...
so, I might give this combo a try.
Can anyone think of any reasons this would be harmful to a Commonrail TDI?

[defever]

Another refill update:

This time around, bit more 2-EHN on the combo (2 stroke oil 250ml; 2-EHN 50ml):

Trip odometer 748mi
Supermarket standard diesel 58.74L
MPG 57.9
DIS discrepancy 5.7MPG

Trip odometer covered similar ratio of 90% motorway and 10% urban. But this time the DIS discrepancy was lower than the previous tank; probably due to an emergence of slight exhaust leak from the exhaust manifold (I need to replace the gasket).

As Gazwould suggested, there are lots of variables to consider, but I will be continuing with this combination (I prepared 300ml 2-stroke and 50ml 2-EHN for the next tank) and see how the MPG changes and how the engine sounds and performs subjectively.

I've had the combo additive for approx 2,000miles and I haven't noticed anything detrimental. Engine noise hasn't changed much since the very first time I added 2-stroke (at the moment it's resonating due to the slight exhaust leak), but the throttle response and acceleration is SUBJECTIVELY and SLIGHTLY better and MPG seems to be bit better.

I'll note again on the next tank refill.

[defever]

Another refill update:

Additive mix: 250ml 2 stroke oil & 50ml 2-EHN
Trip odometer: 773mi
Supermarket standard diesel: 60.04L
MPG: 58.5
DIS discrepancy: 4MPG

It's probably worth mentioning
a) driving condition was 90% motorway 10% urban
b) the exhaust leak is now sealed
c) last 80mile trip was driven very carefully (40-50mph) back to home supermarket petrol station (the DIS calculation was 5miles left until empty!)

That's pretty good result using the home additive mix and supermarket diesel. I think I'll keep on sticking to the ratio until my 2 stroke and 2-EHN supply run out.

[defever]

Hello forum users,

Another, and probably the final, update as I'm seeing some consistency with this experiment.

Last few tankfuls I've been adding 250-300ml 2-stroke oil and 50ml 2-EHN. I'm getting average of 56mpg per tankful and DIS discrepancy is 4-5mpg, most of the times around 4.5-4.7mpg.

It's worth noting that there are lots of factors affecting fuel efficiency; mainly being that it's been a lovely hot summer and my driving habit has become 90% motorway and 10% urban.

All in all, nearly 8 months (roughly 8,000miles) of experiment with a normal supermarket diesel and 2-stroke and 2-EHN, I'm going to conclude that the mix is helping my fuel efficiency (I'm getting the same fuel efficiency of "premium" diesel) , and the engine sounds much smoother than before (the "desiel knocking" is noticeably quieter than before the experiment or compared to other old A4/Passat TDis on the road.

Happy motoring everyone!