Thanks to the Advanced Vehicle Testing Activity at the Idaho National Laboratory, the US Department of Energy has now clocked up one million miles under its plug-in hybrid electric vehicle testing.

The activity looks at plug-in hybrid electric vehicles in real world usage using both fleet and public drivers. The on-road operations have taken place across the US and Canada with more than 26,000 charging events having been accumulated and more than 215 vehicles representing 12 different models – mostly conversions – being used as part of the test fleet.

The testing looks at vehicle performance by quantifying energy consumption in terms of both petrol and electricity. The testing also looks at how environmental conditions, such as air temperature, influence the performance of the technologies.

Speaking about the testing results obtained so far, Jim Francfort from the Idaho National Laboratory talked about how driver behaviour, changing frequency and environmental conditions could all impact the vehicles’ efficiency and miles per gallon results. Drive patterns suggest shorter distances per day than previously documented; and plug-in hybrid operations usually occur with minimal pre-trip charge events.

The Idaho National Laboratory is one of the principal participants in the upcoming deployment of 4,700 battery electric Nissan LEAF vehicles across five greater metropolitan statistical areas. This will document 70 million miles of electric drive operations and more than 1.8million charging events.

The Advanced Vehicle Testing Activity meanwhile, shares its results with industry and government research and development groups in an effort to aid both technological developments and target setting.