Plug-in Hybrid Electric Vehicles (PHEVs) are entering the market and bring with them new OBD issues. A key one is how to measure in-use monitor performance ratio and where to set a standard for this, as PHEVs will have varying amounts of engine-on operation depending on customer plug-in and driving behavior. Toyota?s Prius PHEV system is described and customer use data from a US demonstration fleet is examined. Some prior denominator proposals by Toyota and CARB are explained, as background for the current CARB/industry agreement for denominator and ratio.

Presenter
Morton M. Smith, Toyota