Production Toyota Prius Plug-in to boast more than 13 miles of electric-only range

In the transition from prototype to production form, the Toyota Prius Plug-in Hybrid will reportedly be subject to some minor modifications. It’s believed the production version of the plug-in hybrid, which will make its worldwide debut at the 2011 Frankfurt Motor Show in mid-September, will differ from the prototype in some minor – yet potentially critical – ways.

Sources say the production Prius Plug-in’s battery pack – a 5.2 kilowatt-hour lithium-ion unit – will be slightly smaller than the pack that powers the current prototypes. This, according to Green Car Reports, will increase the Prius’ ability to haul cargo. Additionally, GCR says “sources close to Toyota” have hinted the prototype Prius Plug-in’s 13-mile electric-only range will be improved upon before the gas-electric Toyota hits U.S. dealerships. How much an increase in range will we see? Well, that remains unknown, but a couple of miles would bump 13 up to 15, and that’d be right swell, don’t you think?