Adding 2-stroke oil to diesel fuel

[oldbutnotslow]

See here

I am always dubious about doing this sort of thing.

 

Anyone with a diesel engine techie background who may like to comment?

 

Grant Taylor

[Stationary M25 Traveller]

Wonder if he works for a 2-stroke oil distributor ?

[CharlesElliott]

Question that always has to be asked - if it is so easy, why don't the diesel companies add it at source?

[6speedmanual]

At 0.5% it is very unlikely to do any harm, imo.

Whether the all benefits are as good as he claims would be hard to ascertain without rigourous control testing. Placebo effect of him knowing his diesel contains a dollop of 2T cann't be counted out either.

Certainly in dodgy markets where diesel and kerosene can get mixed up (eg underdeveloped countries) putting up to 2% 2T oil in disel is a good precaution. Kero lubricity is very low compared with 'proper' diesel. This can cause more long term wear on pumps and injectors. On common rail (very high pressure) diesel engines (effectively all diesel cas built in last approx 8 years, the effect of insufficient fuel lubricity can be catastrophic in a short time. Ref. issues of petrol in diesel from incorrect tank filling.

 

Chances are you could come out of a 150,000 mile experiment worse off by £200. (assuming 2T is £5/l)

Need just over 1% improvement in fuel economy to break even. Almost impossible to verify. I record all fuel useage on a brim to brim basis and see variations of around 5-10% from tank to tank, even with great effort to drive consistently on my long commute.

 

(sorry, just filling time whilst I wait at the Chinese take-away 😬 )

 

Peter

 

[Unclefester]

The writer is a lawyer working for car and oil concerns.

 

It sounds as though plenty of testing has already been done by Mercedes and others, and I'd say that it's a very good idea to use semi-synthetic, low ash 2 stroke oil in 1:200 doses.

[Steve, Carol and little Cl]

That sounds really dubious. You´ll probably end up poisoning your NOx trap and ruining your DPF.

 

I woudn´t do it for all the tea in China.

[andy couchman]

There has been a lot on this on the Disco 3 website. Consensus appears to be that adding 2 stroke oil adds lubricity and helps the engine to run cleaner and quieter, with perhaps a 2mpg improvement (for some but not all drivers).

 

The clean issue is more important than it sounds - things like sensors and EGR valves get clogged by too much grime and the evidence seems to suggest that adding oil makes a noticeable difference.

 

Of course you can add a named diesel additive but again the consensus appears to be that 2 stroke oil is just as good and maybe better and is cheaper too.

 

I've done it but have lapsed (which may be why my Disco is now being fixed after running into engine limp home mode ☹️). It's counter-intuitive to add it though and I'd really like a proper engineer to opine on the issue.

 

Anyone?

 

Andy

[Unclefester]

I skimmed a lot of the thread. A major car manufacturer tested all the known diesel additives on the market and found them all worthless, but said the 2 stroke oil is definitely useful.

[Stationary M25 Traveller]

Does it make your car smell like a moped ?

[7 wonders of the world]

don't suppose castrol R would go down to well ..........but arh that smell, takes me back to the karting days

[Stationary M25 Traveller]

Seems to be much discussed on German car sites - Liqui-Moly 1052.

[6speedmanual]

Lobbed 0.5l of 2T into my remaining 50l in my tank before driving to work this morning. 1%

Smoother, Quieter (diesel injector noise), faster, more go per light throttle setting, almost certainly more economical as a result... Fantastic!

Or was it because on my last 10 miles home last light I gave it a really good wringing out.....?

Next fuel-up will go to 0.5% 2T mix. ('cos that's all that's left in the old can in garage from when I used to buy gallons of 2T)

 

Only problem is, How do I actually run a proper control on the benefits?

 

Peter

[velocityblade]

Having read the thread, then looked at some more forum sites (Land Rover, Audi, VW) it appeared to me this practice is anecdotally not new though finding real evidence has been impossible. Most forums quote the "well known German manufacturer" test, with many cut and paste quotes to "prove" the point.

So I figured I should try it on my Accord 2.2 EX.

First tank full - jury is out. Not noticed any real change though if I believe the fill-up to fill-up mpg, it is DOWN 2mpg. Worst I've had since owning the car for the last 4 months. Not scientific so onto the second tank now.

This time the car seems to feel smoother and quieter, but that could be a placebo effect. All indications are that the on-board mpg indicator shows normal returns, so nothing spectacular. Nor noticed any reduced DPF burn cycle either.

I'll update when I have used all the oil after my 3rd tank has been used up.

[velocityblade]

Second tankful used. Mixed results this time. There does seem to be more grunt around 2krpm: wheelspin in 2nd was a bit of a surprise as I wasn't trying that hard. Engine still seems quiet and smooth but the Honda iD-TEC was pretty good already so this may still be imagination.

MPG turns out as before, about 4% DOWN on previous tankfuls without oil, though this time my partner did a lot of miles and never gets the same economy as me. The on-board computer suggested I should have returned much higher mpg figures (750 miles to the tank)but the fuel pump gauge said not.

On to the third tank now. Update after this third tank is used.

[Jonathan Kay]

Anyone up for doing the study blinded? I'll help with the design...

 

Jonathan

[6speedmanual]

Jonathan

I would be interested in your ideas for design of a blind study.

I already wondered about getting a third. party to add the 2T / not as the case may be.

 

A couple of issues.

1. getting the consistency of operating conditions is very difficult. Even on a consistent daily grind and with a very specific tank brimming process, big variations in fuel cons. are noted from one tank to the next.

2. We don't know what cumulative effect there may be from the 2T being in for longer. EG, does the benefit only come to light after 2nd or 3rd tank. Or indeed, do the benefits extend into next tank range even if the 2T is not added. (Can these be be called lag or latency effects?)

 

You views on accommodating these in the test programme would be interesting.

 

P

 

 

[EFA]

Performance improvements come from the improved cleaning of the DPF and the EGR.

 

DPF's are the biggest pain in the 🙆🏻 ever. I would not own a car with one.

 

My current daily driver has the EGR blocked off and the DPF removed and replaced with a straight through pipe. Performance is consistent irrespective of usage (town vs motorway).

[George C]

Some not very technical and probably useless feedback...

 

I have a racing 2 stroke kart and so I tend to have spare 2 stroke fuel in my garage, mixed with expensive two stroke racing oil.

 

Throughout the year I always end up running short of normal fuel and use the 2 stoke stuff in my 4 stroke lawn mower, strimmer and dare I say it, a little in the Caterham (170bhp steel crossflow) to get me to the fuel station.

 

What has suprised me is that all these engines run really well with it. Maybe there is some sort of octane booster in the racing oil. You also get the added benefit that they smell of a racing kart which is a happy event for me.

[Jonathan Kay]

Doing the experiment:

 

Arms would be adding 2-stroke oil or adding the same amount of diesel fuel. Do you want to test different doses, and/ or different 2-stroke oils?

 

Not hard to blind. Possibly easiest by someone else bottling the additive. Could you tell which was which by colour or smell?

 

What outcome measures do you want to study?

* Objective

* Subjective

 

But here's a hard one: how long do you think the effect(s) take to appear? The longer that is the longer the experiment will take.

 

Jonathan

 

[irrotational]

I can think of a couple more issues involving blind driving......

[velocityblade]

I may be able to address a couple of those points 6speed.

Third tank just topped up by about 60% for a busy weekend. Based on diesel used, mpg was better than the first couple of tanks but not back to my usual 50. Engine does seem quieter and the early morning (6am) cold start rattle is no longer there (wasn't that significant before, just not there at all now). I have used the last of the 2T in topping the tank so after this I am running for 3 tanks with no additive.

The DPF burn frequency does not seem to have been altered significantly although on the Accord, it is hard to say when it has kicked in. I keep an eye on the on-board computer to see when the instant mpg drops significantly, then comes back. It may - may - have reduced the frequency by 10% but that is too small a margin to be a reliable stat.

Power around 1750 - 2200 rpm is definitely up. 2nd gear wheel spin is something I haven't tried for but has happened a few times now.

So, my conclusion so far is that after 1700 miles with a variety of driving styles, mpg is down, quietness is improved, power is up. Is it worth the £3 (approx) per tankful for the 2T and the reduced mpg (circa 4%)? Inconclusive.

I'll report back again when this tankful is gone and replaced with straight Tesco diesel.

 

Edited by - velocityblade on 25 Oct 2012 14:45:54

[6speedmanual]

Cheers Vblade.

I have no concerns about risk of any damage to cats, egr, etc.

The only Q is cost v benefit.

As my engine is now middle aged (170k and rising fast) I may just start doping it with 2T.

At 1% I was pretty sure of the improved feeling mentioned in my 2nd post above.

I reckon it may improve longevity of pumps and injectors.

ust trying to source 25l from my local oil specialist. Should be able to get to around £2.75/l.

 

I think your worse consumption may be due to "performance testing" for different characteristics. Across all my measurements, it is so easy to waste 20% by a few sprited drives.

The best tank to tank results require immense discipline, which is hard to sustain over 1000 miles beteeen fill ups! There is always a back road home, a BMW to overtake at a roundabout or a tight schedule up the M40 at some point in the tank range! 😬

 

Peter

[Grim Reaper]

I use 2 stroke oil in my diesel Nitro, I use the cheapest, non synthetic mineral oil you can get.

£2.90 plus vat from here

200:1 ratio.

[6speedmanual]

Good call, Grim. I've had engine oils from S&A. I very much buy oil by spec. not brand.

Now found a similar oil merchant in Northampton where I can collect.

Good for the regular oil changes on my 6 😳 car fleet. Average age 17.5, ave mileage 115,000. 😬

(the 7 significantly drags the average down!)

😬

 

Peter

[Nigel Riches]

A fellow I work with runs his diesel on aviation fuel (Jet A1) which is basically glorified kerosene, and some Shell inhibiting oil, for some extra lube of the pump and injectors, how ever at only 190000 km he has replaced the injectors, as there was palls of smoke from the exhaust, and slow, even for a non turbo ex Japan truck, accelleration, I don't know how bad the air filter was!!!!,

However my 300000 km turbo diesel always run on diesel from the forecourt pump is showing no smoke, good pick up, for a slug, and returns approx 10L/100 km (app 25MPG) OK not wonderful, but not sad for a 1993, 1869Kg 4wd truck.

So may be I'll snitch some of this inhibit oil, sorry upper cylinder lubricant (do you remember STP?) and see if my mileage per tank improves, it's someting to do with the cetane (not octane, as in petrol) level of the fuel.