Cetane number and sulfur content were changed to examine the effects of fuel quality on particulate emissions and SOF content. A range of lubricants were also tested to examine the effects of volatility and ash content. Particulate emissions and SOF content were influenced by fuel quality but more work is needed to identify the detailed effects. The effects of lubricant viscosity were observed to be a change of particulate emissions and fuel economy. Gas chromatography was used to analyze SOF samples to determine the proportion derived from fuel or lubricant. The ash content derived from lubricant additives was examined by atomic absorption spectrometry and inductively coupled plasma spectrometry. PAH emissions were reduced by use of a diesel catalyst, and the reduction rate was measured by high performance liquid chromatography.