Trevor asked: - is 'high sulphur' a 'good thing', for > example (I thought otherwise - but would be happy to be corrected :-) )?
snipped The sulphur content in diesel fuels assisted in the lubrication of mechanical injection pumps. However, it also led to the formation of soot in exhaust gases which, particularly in cities, was blamed for respiratory problems (mainly in children IIRC) and so it was deemed to be bad. Sulphur has been reduced in diesel for many years now (you may recall seeing 'City Diesel' on sale at some service stations some years ago which was low sulphur diesel by another name). Since the Euro IV exhaust emission regs came in many/most vehicles are also now fitted with catalysed particulate filters which collect and store the reduced amount of soot particles produced and burns it off under certain controlled conditions of engine temperature, vehicle speed and particulate filter back pressure. Diesel has gone towards Ultra Low Sulphur Diesel and going to Zero Sulphur to further reduce the sulphurous effects. The materials technology in the new generation of common rail pumps has reduced the need for the lubricity of sulphur in the fuel. Roger
