A Plug-In Hybrid For $3,000? Thank These College Folk For That

The bright minds of young college students and their mentors are at work again in the world of green technology. This time around the scene is Middle Tennessee State University (MTSU) and the item being developed is a plug-in hybrid retrofit kit said to work with almost any car.

Professor Charles Perry and a rotating group of MTSU students associated with the university’s Department of Engineering Technology have, for the last few years, been developing a wheel hub, plug-in hybrid retrofit kit. This green car technology, currently in proof of concept stage, is now being shopped around to private investors for funding to demonstrate a manufacturing version of it.

MTSU Wheel Hub

image via MTSU

Perry’s wheel hub technology, according to MTSU, was recently outfitted on a 1994 Honda station wagon and helped this research vehicle to see a gas mileage increase anywhere from 50 to 100 percent. FuelEconomy.gov indicates, assuming this is the 1994 Honda Accord station wagon, that this car’s original EPA rated combined MPG to be 23.

In a video which you can watch below, Perry describes how the technology works. In essence what is added to the two inner rear wheel brake structures are DC brushless motors. Tied to a lithium ion phosphate battery pack mounted in the rear of the vehicle, they supplement the traction provided by the car’s regular gas engine, both reducing the amount of gas needed and also upping the MPG.

The technology is designed for what would be around town usage. What’s also pretty innovative here, according to Perry, is that the system is built with mostly off the shelf components. How they add the electric traction is what the secret sauce is.

“The whole point was to demonstrate the feasibility of adding the electrical motor to the rear wheel of the car without changing the brakes, bearings, suspension — anything mechanical,” Perry said in a statement.

As for cost if it where to actually make it to market, it would likely price for around $3,000, which is considerably less then what you’d pay for buying a shiny new plug-in hybrid like the upcoming Ford Energi. Possible applications of this, besides in consumer vehicles, could also include companies with vehicle fleets.

And, as a side note, this isn’t the only green tech innovation in the automotive space this university has been tinkering with. In January, for example, a converted Toyota Prius plug-in hybrid powered by solar, hydrogen and ethanol was set to make a cross country drive.

I am the editor-in-chief and founder for EarthTechling. This site is my desire to bring the world of green technology to consumers in a timely and informative matter. Prior to this my previous ventures have included a strong freelance writing career and time spent at Silicon Valley start ups.


  • Reply August 1, 2012

    Donald Mayfield

    No info about the plug in part.  Where is the plug in socket?

    • Reply August 1, 2012


      Based on what I’m seeing, it would likely be a direct connection to the battery in the back of the prototype vehicle at the moment. My guess is a production kit would offer a more refined solution, like an actual plug-in port somewhere.

  • Reply August 1, 2012

    Jesse Walker

    What bothers me is the integration with the normal braking systems.  It would seem that this setup would interfere with operation of standard disk brakes.  And to use some sort of drum brakes is not acceptable, either.     

    • Reply November 5, 2012

      Theo Wink

      rearbrakes consumes only 30-40% of total braking power ,so It might at well being used for regenerating?!

  • Reply August 2, 2012


    Much greener to retrofit old cars than to send them all to the dump and buy new. I wonder if it can work with AWD cars. AWD is a necessity where I live, and it comes at the expense of gas mileage (as does the terrain in general). People own hybrids, but they are their “summer” cars, not their only car, which defeats the point of being green by owning two cars instead of one.

    Of course, the reality is the only green most people worry about is money. Are the fuel savings over the remaining lifetime of an older car worth more than $3000 for the kit, plus the labor cost to install it? Still, proof of concept even if not yet market-ready is a good step in the right direction.

  • Reply August 3, 2012

    Liz Karschner

    This is great! I can’t wait for this to become readily available…I’m so installing on my car, especially since I’m almost done paying it off and it would be perfect to help my car last another 100k miles

  • Reply August 4, 2012


    nice that’s a great idea i love the fact that they integrated it into the rear brake system, 2 or 3 years ago volvo had a prototype electric vehicle with hub motors just like that. with 4 motors you can add a lot more power, and maybe you can use the motor to stop you. today’s brake system is old fashion and outdated anyway. would be cool if they used a charging base instead of a plug you know a base like a cordless home phone where you put your cordless phone on a charging base in the same way you would for a hybrid or electric vehicle.

  • Reply August 26, 2012

    Elizabeth Wilds

    Hate to say it, but with commuting and responsibilities I was spending around $300 a month on gas…so 10 months on a 2007 vehicle that gets 19 mpg avg…I’d say worth looking into it! Just hope it does not get killed and buried like so many other innovations.

  • Reply August 28, 2012


    How does the battery charge? Does the motor turn into a generator above 40 mph, or do you plug it in at night? It’s a very clever idea, btw – and it could turn the vehicle into an AWD vehicle for icy conditions in the winter. Plus I like the idea of using the non-turning rear wheels as a drive train.

  • Reply August 30, 2012


    The patents will be purchased and sealed away forever by companies that see this innovation as a threat.

  • Reply September 11, 2012


    I think this design is great and would seriously consider installing the equipment on my new 2012 Lexus ES350 car. However, how will this retrofit kit operate during bad weather such as during a rain or snow storm? What if the street has 6 inches of water flowing on it or if the car is driven with streets packed with snow?

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