[Dogsbody]

Plenty is written about this on the net, it seems to be since diesel formulation has changed with the removal of sulphur and phosphorous.  A common addition ratio is 200 : 1, so 250 mls per tank on  a gd i30.  The theory being the oil improves the lubricity of the fuel and helps keep the pump happy.  Comments, experiences ?

[Phil №❶]

I'm not so sure the injectors would be happy with that. Diesel fuel is designed to detonate at a fixed temp / pressure, you would be changing the formula, albeit minutely.

[Dazzler]

  Could void your warranty if anything goes wrong... 

[cruiserfied]

I wouldn't be too worried about it.

[sundiz]

Commonly used in old diesels during winter. Winter diesel does not lubricate the pump as well as summer diesel. Also some used gasoline to make the diesel more "liquidy" during sub zero temps, so extra lubrication was needed. Personally I would not use 2-stroke oil in modern commonrail diesel.

I use diesel additives, but I would like to believe that the additives also clean injectors etc. 2-stroke oil is a bit cheaper, but I'll drive 20 000km with one 20€ additive bottle, so it is still not that expensive.

[beerman]

Even if you could.....Why would you? Modern cars are designed for modern fuels. Why play with that?

[Paolo5]

I have been running my diesel with 2 stroke at the rate of 200:1  for over 4 years (50,00km) now. The engine runs really smoothly and has heaps of go in it. It is certainly not demonstrating that any harm has been done.

[Phil №❶]

Diesel is already an oil, so not sure what benefit there is. In a petrol engine where petrol is a solvent, I'd add it.

[Paolo5]

Diesel is already an oil, so not sure what benefit there is. In a petrol engine where petrol is a solvent, I'd add it.

Call it a placebo if nothing more.
I also run 2 stroke at the rate of 1ml/1 litre of petrol in my Getz.

[Phil №❶]

You are altering the Diesel formula, ever so slightly. 2 stroke oil is designed for petrol engines and on that basis, will detonate in a Diesel engine before the Diesel fuel. If the piston has not reached it's optimal firing position in the cycle, you may be losing power, rather than adding or protecting the engine IMO.

[Trazza]

I like posts that make one think, but I am not an expert so please help me to understand the point of additional oil (diesel or petrol). 

As I understand things, all fuel types are derivatives of oil. Diesel is lowest, ie less refined than petrol. With diesel oil is still present in the fuel source, which, along with the internals of a diesel engine,  give it more torque and energy per unit than a petrol motor. Adding a small amount of oil to the mix shouldn't change things (mixture too rich if too much is added, too lean if too little oil present). But I would think you'd need to add more than 1ml/litre to upset the balance.

In petrol engines, the fuel has been stripped of oil, so wear and tear is dealt with by the sump oil and does not become part of the fuel-engine-drivetrain energy conversion equation unless there is damage to the block.  So, adding oil via the fuel inlet is not recommended?

Yes, no, way off base? 

  I appreciate patience with me while I try to keep up with you men,  and educated ladies on this forum.

[Phil №❶]

Sort of. The 2 stroke oil is not standard oil, but a type that can be burned as part of the petrol burning cycle, therefore, it burns at lower temperature and under compression must ignite earlier than Diesel oil. Modern petrol engines using ulp fuel have lower compression ratios than older type cars. The 351 Ford GT was 10:1 IIRC. I think today they are about 8 or thereabouts. Our Diesels use compression to ignite the fuel at something like 17:1 ratio, so adding a light oil wouldn't improve things a lot IMO.

It's common for petrol owners to add Redex and other additives to help lubricate the valve guides and theoretically improve engine performance. 2 stroke oil wouldn't hurt a petrol engine at all.

[sundiz]

Diesel is already an oil, so not sure what benefit there is. In a petrol engine where petrol is a solvent, I'd add it.

Some oils lubricate better than others. I believe that the two stroke oils is a better lubricant than diesel as it is lubricating engines without normal engine oil. It lubricates the high pressure pump better especially with low quality diesel. Also there are different types of diesels for different types of climates. High temp diesels are said to be better lubricants than low temp diesels. Can't see nothing wrong adding a little bit of two stroke oil in the diesel, especially if the diesel is poor quality or if it is for cold climates.

[Paolo5]

The 351 Ford GT was 10:1 IIRC. I think today they are about 8 or thereabouts.

Hi Phil,
Thanks for your thoughts here....just checked specs on the humble Getz...the 1.6 litre engine has a compression ratio of 10:1...Falcon GT territory! 

[Phil №❶]

Wow,  So you are using premium fuel then 

[Paolo5]

You bet!!! Well...95 Octane...