A team of engineering students and their professor at Middle Tennessee University in the US have come up with a hybrid retro-fit electric kit for any standard car, which they claim can cut fuel consumption in half on city journeys. Unlike other similar concepts, this invention makes no alteration to the vehicle’s existing suspension, brakes or other transmission parts.

The team, led by Dr Charles Perry, have been working on the retro-fit hybrid electric kit idea since 2008, and currently have a prototype version working on a 1994 Honda station wagon. The system works by adding two electric motors to the rear wheels of the car, over and around the existing wheel hub and brakes, and then hooking up a Lithium Ion battery pack and controller in the trunk. The idea sounds simple, but as Dr Perry explains in this video, the clever and patent pending part is how they transfer the motion from the electric motors to the existing transmission system.

The electric hubs don’t replace, but instead augment the existing power coming from the car’s engine, which means the vehicle uses less fuel to achieve the same acceleration and forward motion. The system switches off at highway speeds and goes into freewheel mode, which means that the system is better suited to short range city driving than highway use.

Dr Perry hopes to get the size of the battery pack and controller down to the size of an airline carry-on case, and is looking to keep the cost down to around $3000 for the kit, once the product is in full manufacturing. Even with the kind of price bloat that inevitably occurs with this sort of project, that’s a pretty competitive price, especially if gas prices continue to rise.

Dr Perry and his team are now seeking funding and support to take the project to the next level. “We have gained proof of concept in terms of feasibility,” he said. “We need quite a bit of money to have proof of product. What we’ve achieved is a demonstrated technology, not a proven technology. Investors want to see proven field-tested performance and reliability. We have to pass through this transition, from feasibility to true, viable product.” [Via]