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2 Stroke Oil Mixed With Dieselfuel...good....bad Or ...dangerous????

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I am considering to add 2 stroke oil in diesel fuel , mixing ratio 1/200. This in order to have a better lubrication of the injection system. According to the responses that I have already read it can't hurt and would the engine run smoother then regular; others say that it is, indeed, harmful. What do you think about this? Should I do it or not?

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Don't know about your country but in the UK they add 5-7% (depending on supplier) bio-diesel (veg oil) to diesel

This replaces the lubricants (sulphor) that used to be in Diesel but is removed in modern diesel to reduce smoke/ pollution

Recently designed diesel- engined cars are tested to work with the modern low-sulphor diesel and are fine without additional lubricants (as above, the veg-oil acts as a lubricant)

Earlier common-rail diesel engines (roughly 1998-2007) may have problems with low - sulphor diesel, the (pre) added veg-oil may be enough to lubricate the pump/ injectors but these components were not designed for this fuel

A little low- ash 2-stroke oil may help to prevent wear on these components, and there have been reports of engines running smoother & quieter

You must be careful, though, 2-stroke oil was designed for 2- stroke petrol engines, not 4-stroke diesel engines, some 2- stoke oil may react with diesel or the veg-oil (bio-diesel) added to modern diesel there are

There are 3 basic types of 2 stroke oil -

Castor based

Semi - synthetic


These cannot be mixed, if you are running a 2-stroke petol engine on Castor based 2- stroke oil and wish to switch to synthetic, you must strip the engine down, clean off all the old (castor based 2-stroke) oil/ wash it out with petrol, rebuild the engine using the new (2-stroke synthetic) oil, and run it with the synthetic oil - you cannot use Castor- based 2- stroke again without going through the same procedure - mixing 2 types of oil may cause a reaction, producing a "gloop" which can block oilways which may cause an engine siezure (on a 2-stroke petrol engine)

So if you are adding 2-stroke to your 4- stroke diesel engine, best to stick to 1 type of oil (Castor based / semi synthetic or synthetic) - or one make of oil to be on the safe side

Castor based is an old type of 2-stroke it tends to smoke more and cannot withstand high tempratures as well as the other 2, synthetic tends to be more expensive than semi- synthetic

Some oils are expensive and adding 2- stroke oil will add to the cost of running your diesel - for most people, the bio-diesel added to modern diesel should be sufficient to lubricate your pump, injectors etc - adding a little 2-stroke oil (and sticking to the same type/ make) is unlikely to do the engine any harm (as long as the oil does not react badly with the diesel) the oil has a zero cetane rating (no calorific value) but is being added in such small realative quantities that this will not significantly reduce the overall cetain rating

Try a little low-ash 2-stroke and see what happens - if the engine runs smoother, quieter and faster, without increasing the smoke output - its all good , let us know how you get on, anyway

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I'd posted a thread about diesel engines and adding 2-stroke oil, on the Dutch forum Ford Mondeo Club (FMC). A member has, as a test,filled his tank and added up to 300 ml of oil. The test is started yesterday, until the next refueling. He is quite excited about the first day: he says that the engine is quieter and running smoother AND that consumption has been reduced by 0.5 litres/100 km/62.1 milles. Considerably if you ask me. But the test is only successful after the second refueling is done.

Keep you updated.

If it is succesfull, I will follow.

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In general he is satisfied.

There has anyone reported that he's doing the test for allmost 10.000 kms, now

his findings: from first addition indeed quieter stationary running , nailing cold engine almost completely disappeared,

fuel consumpsion: 0.5 L/100 kms less

I am convinced of the benefits of this addition.

I will follow :)

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Last Saturday I bought 2 stroke oil and added 300 ml to the diesel (full tank).Meanwhile already drove aporx. 150 km, mostly freeway.

Positive results so far, but it is only the beginning.

The results so far: smoother running, not nailing(is it the right word?) at cold start....

consumption: less then before ( cc 120km/h 6th gear: current 4.0 - 4.4 L/100 km (unbelievable, but true) - before aprox 5.0 L/100 km. But, as i've said: this is only the beginning......

As I increased speed upto 180km/h, consumption rised smoothly upto 5L/100km .........

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