The Truth About Adding Two-Stroke Oil To Diesel In Modern Common Rail Engines

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It seems counter-intuitive to be utilising 2-stroke oil in diesel on common rail, low emission vehicles. The actual premise behind adding 2-stroke does carry weight in certain instances. Vehicles equipped with Bosch, Delphi, or even Siemens fuel systems generally don’t need it. Therefore, you’re unlikely to see a significant change in engine performance or noise with the use of 2-stroke Oil in the diesel.

When and how to use the 2 Stroke in Diesel:

However, if you have a 2005-2012 Denso Common Rail equipped system, your vehicle will most likely notice significant changes. You need 2-stroke premixed oil.

Do not use in cars equipped with DPF

How 2 Stroke in Diesel Works:

The reason why this mixture creates a beneficial difference is quite simple. With Denso Common Rail operating systems, nearly all failures we have seen at Bailey’s Diesel are seizure related or seizure based failures. The injector becomes sticky; it generally loses tolerance and shows symptoms such as cold knocking. The idea behind adding 2-stroke oil therefore makes a lot of sense, because we’re adding lubrication where the main failure mode is seizure related.

The other interesting thing is that when we fitted all of our injectors with DLC coated injectors, we noticed a significant difference in the engine noise and smoothness. The DLC coatings applied inside our injectors create a permanent, very hard and low friction surface .So I thought if the low friction was worth a try, we should test this 2-stroke myth, and we were surprised when it actually worked quite well.
Our Conclusion
So the reality is if you have genuine Denso injectors or the original injectors in the car, and it’s pre-2012, then adding a little bit of 2-stroke will create a longer service life for the injector, but also make it a little quieter and smoother in its daily operation.
The general premise behind it: mineral-based, 2-stroke, low-ash and 3mil of oil per litre.

  • Ben

    So my 2013 Isuzu DMAX has isuzu injection, is there any benefit to running 2-stroke?
    I have been using it at close to the quantity suggested in this article and previously have done in my RD28 patrol and noticed a considerable difference (no the RD28 is not CRD but ntl) Since running 2T in the dmax I have returned better fuel economy figures of almost a litre per 100 in the same conditions, less injector noise and better throttle response. The vehicle has done 120k. Should I stop running 2T?

  • Chris

    Interesting article guys, I have been toying with the idea of putting it in my 2007 NS Pajero for some time.

    Two questions:
    1. How would I find out what my 2007 NS Pajero is running?
    2. Why should you not add TSO to a vehicle post-2012?


    • Matt Baileys

      Hi Dave;
      Thanks for the message.

      You certainly can, no harm can come from it. only we don’t see these types of failures with the newer injection (especially on the Siemens system fitted to yours) that would suggest that you would need to.

      But again, its certainly something you can experiment with.

      Hope this helps

  • johann marthinsen høgslund

    Okai common rail may dont like it, But i think is good for Turbodiesel engines with older fuel pump like Bosch ve pumps. 2-stroke oil is an old mechanic trick whitch says that the injection nozzles gets Lubricated and does nothing harmfull then cleaning.


  • Jesse

    I have a 2013 model ranger and it has made big differences in noise response and smoothness of the engine . Iv also put it in early 2000 model tucks also making big differences in noise and knock .

    • Matt Baileys

      HI Jesse;

      Interesting input! Cheers for the feedback. We suggest that it may not be needed or of benefit from the Rangers / BT50 based purely on failure modes. But we’ve not done the testing in terms of engine performance. So that’s a interesting finding.

      Thanks again for the input.

  • Glenn

    I have a Hilux built in 2012. I am assuming that Toyota made the changes to the injectors some time during 2012. How could I determine which injectors are in my vehicle as to whether adding 2-stroke oil would be beneficial? Alternatively, does adding 2-stroke oil harm the vehicle if it has the newer injectors anyway?

  • Graham

    I know that the guys that reuse aviation kero (jet fuel) add 2 stroke oil to it.
    I have a few litres of good quality TCW3 2 outboard oil left over from when I changed the engine on my boat, would this be suitable to add to diesel?

    • Matt Baileys

      G’day Chris, if you just bought injectors off us, dont bother with the 2stroke. the injectors manufactured by us have engineered and permenant modifications that mean you no longer need to!

  • Peter

    A lot of 2-stroke oil being sold these days is listed as “semi-synthetic, low smoke”, which I presume is a blend of mineral and synthetic oils. You specify a mineral-based oil, but is this blended oil also suitable and if it’s not, could you please explain why? Thanks for your help. Very interesting article.

    • Matt Baileys

      Hi Peter,

      We have noticed that the Syn + Semi Syn oils do not like to ‘mix’ and fall to the bottom of the fuel tank, hence the requirement of mineral. Also, its noted that some of the ‘additives’ that they place in Modern full Syn 2 stroke (which helps there intended purpose) can infact harm the CR Fuel system. Ultimately, the ‘older’ style of 2 stroke (no additives, full mineral) are really the pick.

  • Wayne Rattenbury

    Hey. I spoke to Paul from yd25 regarding problems with my injectors in a 07 D40. He also advised to put 2 stroke oil into fuel tank. It’s making knocking noise and not willing to replace them for $2800 after an exchange. Will try your theory in a few days. Cheers guys

  • Nick

    Hi I have a 2007 land cruiser ute and have added TSO to the diesel and has made a massive difference to the rattle. I am just wondering if this should be done in every tank or every couple of tanks.

  • Scott

    My 2012 Sahara purrs like a kitten. One of my 79 series 2013 has a bit of knocking and the other 79 2012 is quiet as. when did toyota start using the improved injector

  • Matt

    Very curious about this article
    Running a 75 series Troopy 1998. 4.2l
    Do you suggest the same as the rest mineral 2stoke at a 3ml per litre
    Cheers Matt

  • Rollin mondon

    Thanks for info i had problem few yrs after buying the car from lander toyota 2007 hilux 3litre turbo the injector fail feedback put ceramic coated denso can i used the 2 stroke oil now in the fuel diesel common rail system.

    • Matt Baileys

      Yeah, you definitely should.
      Theres no “ceramic coating’ only DLC. and the parts that were supplied only have the nozzle needle coated, not the control piston, which is the commonly seized part… so this 2 stroke article was written for exactly your situation.

  • Dan Gough

    How do you go with Crd with DPF blockage with the two stroke mix? Does this bring the CAT temps down on standard driving or cause any problems with SCR? Dan

  • Raviklp

    Hi Team, could you please help if there would be any long run complications if 1’ll 2t oil per liter of diesel is mixed for FIAT Linea multijet 1.3 engine. Uses Bosch injectors as I’m aware. I used this ratio for 2 tankful and impressive response and felt smooth engine like petrol.

    Please advise if I can continue using this ratio

  • Bengali ted

    I have a mk4 gttdi ajm 115bhp with a straight through pipe (cat has been gutted and no muffler) and its at 200k ?

    Before the car had a straight pipe i used to use 2 stroke with shell fuel saver, but since a straight pipe my car absolutly hates normal diesel even with 2 stroke. Since then i tried vpower full tank with 300ml of asda 2 stroke oil and WOAH THE TORQUE IS AMAZING! But before i had the straight pipe i had tried the vpower and 2 stroke which lead to the engine running sooo smooth but not enough torque ?. The car is not remapped yet.

    i have looked everywhere to see if anyone else has tried this but i have not yet found any info.

    But am going to list the way it runs below –

    1. The car has NO black smoke though its a straight pipe
    2. Runs very smooth and the Cooo/owl sound is more clear for some odd reason

    There are alwo other benifits to the 2 stroke as well which im sure you can find out with a quike google search.

    Now i have no idea if mixing 2 strokev with vpower or any other premuim fuel (tbh only vpower puts a smile on my face) is good or bad as they dochave additives which may not go well with 2 stroke oil. But for me using vpower and 2 stroke on my car since a straight pipe was put on has made a cery noticable difference.

    Anyone know anything else? Or even given this a try?

    Would love to hear other 1.9 pd owners experiances ?

  • Chris

    Hi Matt, will the 2011 MN Triton diesel benefit from using the 2T oil? I have a 125lt tank so you would recommend to add about 3.5 litres of 2T per tank?

    • Matt Baileys

      yep. This model is fine and should respond.
      Ratio’s are a little wrong however. you need to add 3cc/ litre of diesel, so in your case its around 375cc for the whole tank of 125L
      hope this helps!

  • Glenn

    Hello, Name is Glenn, I have just bought my first diesel. It is a 2011 Hiace commuter with 101 Ks which I intend to convert to a campervan. It is running a D4D, 5 speed manual. So I am on a completely new learning curve with diesels any help you can give me will be appreciated. I do not know what fuel system it is running.

  • Colin

    Hi Matt,

    I’ve got a 2002 Nissan X-Trail with a 2.2 Di engine (YD22DDTi) that uses a Denso HP2 pump, I’ve had to get the SCV’s (red and green) replaced three times now and have read that it might be due to the lack of sulphur not lubricating and so they’re sticking. Do you think this would make a difference in my case ? It has a 60 litre tank so I guess that would be 200ml of 2-stroke mineral oil per tank. Also if adding this is it ok to use cheaper supermarket fuel or should stick to Shell/BP/Esso. This is in the UK.


    • Matt Baileys

      Most likely not. Yours is the model least effected by lubricity (aka the better injectors). Smoke is probably due to wear. Towing and high loads mean more fuel at higher rail pressure = faster / more wear for the km. Hope this makes sense / helps

  • Nick

    I have a 2008 d40 turbo diesel it’s running really rough while idling, blowing a lot of white smoke when cold and a bit under acceleration while it’s warm, turbo whines when cold and struggles to get on boost but is fine when its on boost and the exhaust has a distinct smell to it.

    I’m pretty sure the turbo needs to be changed but could this be the injectors as well?

    • Matt Baileys

      Hi mate, the white smoke and so on does actually sound like Turbo seals are on their way out. Normally speaking but, that has no impact on engine ‘smoothness’ – so maybe is turbo and injectors?
      Id suggest having a competent mechanic asses the turbo in situ, if confirmed change that. Whilst their, check the injector feedback values and make a decision from that.

    • Matt Baileys

      maybe. Given the old style of fuel system, adding 2 stroke is unlikely to add any longevity to the system – unlike Common Rail. That being said, i’ve heard of people claiming smoother engine running and what now.
      Basially you don’t ‘need it’ like Denso CRI, but it won’t hurt either.
      Give it a go and let us know the results.

  • Bruce Stevens

    G’day Matt, recently bought a 2010 Hiace SLWB van 3.0 1KD auto its done 314K but purrs like a kitten. Two questions its a 70Litre tank so do I add about 200mls of 2T per tank or a bit more?? 2nd question ….Which brand of Diesel would you recommend or are they all much the same??

    Cheers Bruce

    • Matt Baileys

      G’day Bruce
      Go BP – thats my pick. their guaranteed ‘minimum standard’ is much higher than the others.

      yeah mate, around the 200ml is it for the tank. Add it before you fill, so when it fills its mixing up for you.

      Let us know how you go!

  • Bruce Stevens

    Thx Matt, I work as a courier here in Adelaide and do mostly city driving with occasional short highway runs(between 150 and 200km per day). Although did a country job Friday Gawler to Mannum and gave her a good long run at highway speeds. I refill when the fuel light comes on and usually have to only put about 55litres in. Having driven a 2litre Econovan for last 4 years the 1KD powered Hiace is an animal….


  • Raul Melchor Garbanzos

    H Matt I live in the Philippines I have a Ford Everest 2009 2.5 liter duratorq CRDI will putting 2t oil beneficial to its operaration.What brand of injectors does Ford have?Recently I put 2t oil on my Mitsubishi L300 FB van 4d56 non turbo mechanical zexel fuel pump no noticeable effect.

  • Edwin

    Hi Matt I have a 2015 GLX Monterosport and Ive been adding 2T oil since last month (Feb ).. though I dont follow the exact ratio as recommended, 250ml of 2T oil fir 24L of Diesel but I have seen some significant changes specifically to the engine noise. Will this affect my engine in a ling term since mine is a 2015 4D56 engine? Thnks for the reply.

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