Fuel Quality Effects on Oxidation Exhaust Catalysts in Light-Duty Diesel Motor Vehicles

The influence of fuel quality on oxidation exhaust catalyst (OEC) efficiency in decreasing emissions of carbon monoxide, total hydrocarbons and total particulate matter (PM) from diesel cars has been investigated. Both in-house test results and further interpretation of published chassis dynamometer data have been utilised.

Intrinsic OEC activity, which depends on exhaust gas temperatures, is shown to be largely unaffected by fuel quality, other than sulphur content.

OECs affect PM emissions by changing the ratio of the soluble organic fraction to fixed carbon within engine-out PM. This ratio is strongly influenced by engine design and operation mode and to a lesser extent by fuel cetane number.