EPA Approves GreenMan's Request for Dual Fuel Vehicular Test Exemptions

First Company to Be Granted Exemptions for Aftermarket Retrofit Dual Fuel Upgrades; Critical Step Towards Launching 2011 Domestic Dual Fuel Vehicular Initiative

CARLISLE, IA--(Marketwire - December 20, 2010) - GreenMan Technologies, Inc. (OTCBB: GMTI) announced that its American Power Group Inc. ("APG") subsidiary has received a Vehicular Memorandum of Exemption and eleven initial Test Exemptions from the United States Environmental Protection Agency ("EPA") for the testing and verification of APG's unique non-invasive dual fuel upgrade system for aftermarket diesel truck and tractor engines.

APG's dual fuel system converts diesel engines and generators to function more efficiently and at a lower operating cost (net fuel cost savings of 25% - 35%) by seamlessly displacing 40%-70% of the normal diesel fuel consumption with CNG, LNG, or bio-methane. APG's system is non-invasive to the OEM engine and operates within all OEM performance controls with the flexibility to return to 100% diesel operation at any time. APG's dual fuel conversion and emissions reduction systems can help users achieve their sustainability goals through lower carbon monoxide, nitrogen oxide, and particulate matter emissions. In addition, the introduction of natural gas through APG's dual fuel system does not impact diesel engine performance and will also assist in extending the engine's oil life as natural gas is a cleaner burning fuel compared to diesel.

The initial test exemptions will allow APG to gather critical engine performance and emission data on a pre-dual fuel and post-dual fuel basis to support EPA approval requirements and commence commercialization of their non-invasive dual fuel upgrade system in the United States. The initial vehicles to be tested include nine Class 8 tractors covering various Caterpillar, Detroit Diesel, and Mack engine models ranging in age from 1994 to 2005 as well as a 2008 Ford F450 Pickup and a 2004 Sprinter Van with a Mercedes Benz engine. Both compressed natural gas (CNG) and liquid natural gas (LNG) fueling systems will be tested. In addition, the Company has been approached by over 70 companies operating diesel fleets ranging from 10 vehicles to over 10,000 vehicles in the refuse, route delivery, large and small fleet logistics, mining, and government diesel vehicular markets. APG expects to apply for additional test exemptions for a wide range of third-party engine models classified as intermediate age or over full useful life due to age or mileage.

Lyle Jensen, GreenMan's President and Chief Executive Officer, stated, "In a year when APG has successfully conducted aftermarket trials and is beginning commercialization of our vehicular dual fuel solution in many international markets, the granting of these initial test exemptions in the United States is a major strategic milestone for APG. We now have a path to demonstrate and document the positive economic and environmental impact that our dual fuel system can have on aftermarket diesel vehicles operating on the highways of North America. Based on independent marketing research conducted by Power Systems Research, it is estimated that over four million vehicles or 80% of the five million medium to heavy duty diesel vehicles on the road today, are model year 2006 or older. These vehicles are ideal candidates for APG's upgrade technology."

Mr. Jensen added, "The significant appeal of APG's non-invasive dual fuel technology to this multi-billion dollar addressable market makes sense for numerous reasons. APG's dual fuel conversion and emission reduction system can significantly reduce CO, NOX and Particulate Matter emissions on the older and more polluting diesel engines while delivering a 25%-35% net fuel savings. This is only expected to improve as diesel prices continue to climb. Due to the clean burning benefits of natural gas, oil life and maintenance cycles can be extended. Lastly, given a driver can return to 100% diesel fuel at any time, there is no 'range fear' of running out of CNG without the ability to refuel."

Mr. Jensen concluded, "I want to personally thank our Algona and Detroit-based engineering team as well as our Detroit Automotive Supply Partners for designing a third generation digital system that is robust, safe, and a low-cost market leader. We believe we have identified the correct strategic partners to allow us to handle a wide range of vehicular growth scenarios in the United States as the existing path to commercialization, and any further streamlining measures are implemented."

About GreenMan Technologies
GreenMan Technologies, through its subsidiaries, provides technological processes and unique marketing programs for alternative energy, renewable fuels and innovative recycled products. The Company's alternative energy subsidiaries, American Power Group, Inc. (APG) and APG International, Inc. (APGI) provide a cost-effective patented dual fuel technology for diesel engines. APG's dual fuel alternative energy system is a unique external fuel delivery enhancement system that converts existing diesel engines into more efficient and environmentally friendly engines that have the flexibility to run on: 1) diesel fuel and compressed natural gas ("CNG"); 2) diesel fuel and bio-methane, or 3) 100% diesel fuel depending on the circumstances. The proprietary technology seamlessly displaces up to 65% of the normal diesel fuel consumption with CNG or bio-methane and the energized fuel balance between the two fuels is maintained with a patented control system ensuring the engines operate to Original Equipment Manufacturers' ("OEM") specified temperatures and pressures with no loss of horsepower. Installation requires no engine modification unlike the more expensive high-pressure alternative fuel systems in the market. Our Green Tech Products, Inc. subsidiary develops and markets branded products and services that provide schools and other political subdivisions viable solutions for safety, compliance, and accessibility including recycled surfacing. See additional information at: www.greenman.biz, www.americanpowergroupinc.com, and www.playgroundcompliance.com.

"Safe Harbor" Statement: Under the Private Securities Litigation Reform Act
With the exception of the historical information contained in this news release, the matters described herein contain "forward-looking" statements that involve risks and uncertainties that may individually or collectively impact the matters herein described, including but not limited to the fact that we have sold the tire recycling operations which have historically generated substantially all our revenue and that we will be prohibited from competing in that business on a regional basis until 2013; the risk that we may not be able to increase the revenue or improve the operating results of our Green Tech Products or American Power Group divisions; the risk that we may not be able to return to sustained profitability; the risk that we may not be able to secure additional funding necessary to grow our business, on acceptable terms or at all; the risk that if we have to sell securities in order to obtain financing, the rights of our current stockholders may be adversely affected; the risk that we may not be able to increase the demand for our products and services; the risk that we may not be able to adequately protect our intellectual property; and risks of possible adverse effects of economic, governmental, seasonal and/or other factors outside the control of the Company, which are detailed from time to time in the Company's SEC reports, including the Annual Report on Form 10-K for the fiscal year ended September 30, 2009. The Company disclaims any intent or obligation to update these "forward-looking" statements.

Contact Information:

Chuck Coppa
Lyle Jensen
GreenMan Technologies, Inc.

Investor Relations Contacts:
John Nesbett or Jennifer Belodeau
Institutional Marketing Services (IMS)