found this on another forum I'm not going to do it I just thought id show everyone to all interested: 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 negativ 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 (sulphor contained) diesel. The engine-research centre of a well known German car manufacurer 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 homoeophatic dosis 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 burnes 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 clogg, and the "burn free" process of the DPF will be much less. One more information: in Germany we have to present our cars every 2 years to the TUV -Technical Supervision Organisation - who will check, amongs 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 milage by 3-5%. and more :- You may all know that Mercedes Benz have conducted in 2007 a long distance reliability test with a number of Mercedes E-Class 320 cdi from Paris to Beijing. Due to the fact that the diesel quality in East European Countries, Russia and China does not meet the DIN requirements, and Mercedes did not want to take the risk of their engines to flopp due to lousy fuel, the total tour has been accompanied by diesel tanks to re-fuel the E-Class cdi's. Selected members of the Mercedes clientele could apply to participate in selected parts of this test-tour, and advocats and notaries had to certify the correctness of this long term reliability test. Although Mercedes does not like it published or made public, it is a fact that the diesel-fuel used for this test did contain 2-stroke oil to grease the high pressure pump components and to keep the engines clean during this marathon. Why our car manufacturers do not officially allow the homoeophatic addition of 2-stroke oil to the diesel fuel has many reasons, mostly of legal nature. Besides this, which car manufacturer has any interest in excessive reliability of their engines? Their repair shops will have great problems. Meanwhile the "2-stroke-oil to diesel" issue has attracted the interest of a number of Universities in Germany, as this 2-stroke oil has shown to have amazing poperties if added in a small dosis to diesel fuel (1:200), especially the positive impact on air pollution, reduced fuel consumption and improved long term reliability of the diesel engine. The pro and con discussions will go on for a while. But as soon as an accademic report has been published by one of our Universities, this will change very fast. By the way: all car manufacturers reject the addition of any fuel "additive" in their cars, and warn that guarantee MAY be affected. Nobody says, that guarantee WILL be rejected. 2-stroke oil in its properties is not an additive, as you add oil to oil if you "dope" you fuel with a dosis of 2-stroke oil. The dosis of 2-stroke oil in your diesel-fuel is very difficult to analyse, as every (chemical) analysis has the main function to identify substances which are harmful. But 2-stroke oil has proven not to be harmful at all, on the contrary! Personally, I use 2-stroke oil now for many years in all of my diesel cars (my present business car is a Mercedes 320 cdi DPF Automatic). And I never had any problems whatsoever.