Idaho National Laboratory Completes 1 Million Miles of Plug-in Hybrid Testing
 

The test fleet is made up of 215 vehicles, using 12 different models including the ubiquitous Prius...

http://avt.inl.gov/images/phev/hymotionprius.JPG

... And the funky looking Renault Kangoo PHEV...

http://avt.inl.gov/images/phev/Kangoo.jpg

I haven't delved into the detailed reports, but for those interested in plug-in conversions, DOE's Advanced Vehicle Testing Activity (AVTA), INL, and testing partner Electric Transportation Engineering Corporation have released a bunch of reports.

The goal of the test was to compare energy consumption of the PHEVs to non plug-in vehicles.

Not surprisingly, they determined that the main factors affecting energy use were driving style, state of charge, and ambient temperature.

Interesting nugget:

Advanced Vehicle Testing Activity - Plug-in Hybrid Electric Vehicles

So, even at their worst, they were better than the rest.

Hopefully consumers will now demand vehicles have a much higher level of efficiency and manufacturers will be forced to produce them.

INL Vehicle Testing Results
 

You can learn more about Idaho National Laboratory's research projects including more information about the hybrid vehicle testing results at the lab's facebook site.
Idaho National Laboratory | Facebook

Thanks for the link, htomfields.