If we are truly serious about slashing the amount of oil America imports, we must address the most popular and inefficient vehicles that are already on the road, not just new vehicles. To date, a number of companies have tackled the idea of retrofitting the existing transportation fleet with plug-in hybrid technology.

Year-after-year, the Ford F-150 pickup truck tops the sales charts. The F150’s ubiquity (and utility!), combined with its fuel-thirsty nature makes Ford’s popular pickup the most logical choice for aftermarket plug-in hybrid development. Over the years, I’ve shot segments on three different efforts to electrify the F-150, with the latest being this piece from the 2011 SEMA show last month in Las Vegas.

Xtreme Power takes a completely different approach that uses lead-acid batteries, rather than lithium-ion batteries. Xtreme Power’s system uses a highly-innovative fully-submersible switched reluctance motor and is designed to be installed in two hours or under. The company claims a 60% improvement in city gas mileage, with an added 350 foot pounds of torque.

To demonstrate the rugged nature of their kit, Xtreme Power displayed a Jeep Wrangler with their plug-in hybrid kit installed, along with the F-150.