Impact of FAME on the performance of three Euro 4 light-duty diesel vehicles – Part 2: Unregulated emissions

Report no. 7/14: In 2009, EU legislation mandated that 10% renewable energy must be used in road transportation by 2020, primarily through the use of bio-blending components. Fordiesel fuel blending, Fatty Acid Methyl Esters (FAMEs) manufactured from different natural oils are the most likely to be used in significant volumes over this timeperiod. FAME products have been used in Europe for many years, both as blends and as neat fuels in some niche markets. Concawe has completed a vehicle study in which one hydrocarbon-only diesel fuel and three blends of this fuel with FAME (from a single batch of Rapeseed Methyl Ester (RME)) were tested in three Euro 4 light-duty passenger cars. All vehicles used exhaust gas recirculation and were equipped with some type of diesel oxidation catalyst.

One vehicle did not have a Diesel Particulate Filter (DPF) while the other two vehicles were equipped with DPFs that were regenerated using two different approaches. The FAME contents of the test fuels varied from 0% to 50% v/v in order to accentuate the effect of RME on the energy content of the blended fuels and on the emissions from the vehicles. The study was statistically designed and completed using a robust and repeatable testing schedule during which fuel consumption and emissions data were collected over different regulatory andtransient driving cycles.

These cycles included the New European Driving Cycle (NEDC), the ARTEMIS cycle, and two constant speed conditions. The effect of RME on fuel consumption was reviewed in Part 1 of this study. In addition to the gaseous tailpipe emissions, particulate matter (PM) and particlenumber (PN) emissions were measured using the Particle Measurement Programme (PMP) regulatory procedure. Total PM, total PN, and solid PN emissions were measured as a function of RME content. In addition, the PM samples were chemically analysed for their soluble organic fraction, the fuel and lube contributions to this organic fraction, ionic species (nitrates and sulphates), and elemental carbon (by difference). Several carbonyl compounds were also collected from the tailpipe exhaust and characterized.