Evaluation of factors influencing emissions from tractors and construction equipment during realistic work operations using diesel fuel and bio-fuels as substitute

Swedish Environmental Class One (MK1) diesel fuel and three diesel substitutes were compared during steady state conditions, during transients and during work operations commonly performed by tractors and construction equipment. This was carried out in order to determine how fuel, typical engine load/speed and transient effects influence emissions and engine efficiency during common work operations. The results showed that the differences between the fuels were small, except for particulates. Differences in typical engine load/speed and transients effects could; however, cause emissions to vary between 0.5 and 3 times those expected from the current (steady state) ISO 8178C1 cycle, whilst the fuel consumption was only moderately affected. Transient effects appeared to be able to double the emissions.