American Power Group Receives Follow-On Orders Valued at

LYNNFIELD, MA--(Marketwired - May 8, 2013) - American Power Group Corporation ( OTCQB : APGI ) announced today that its subsidiary, American Power Group, Inc. ("APG") has received $500,000 in follow-on purchase orders since April 1 ^st from three top domestic oil and gas exploration and drilling companies. The orders are for the upgrade and conversion of additional diesel generators on drilling rigs for operation using APG's Turbocharged Natural Gas™ Dual Fuel System. SourceOne Engine Equipment, LLC, our domestic Dealer/Certified Installer booked the orders. While the end customers were not disclosed for proprietary reasons, a recent industry survey ranked these three companies among the top 50 oil and gas exploration and drilling companies in the United States.

Lyle Jensen, CEO of American Power Group stated, "Currently more than 20 of the top oil and gas exploration companies in the United States are running APG's Turbocharged Natural Gas™ Dual Fuel System on their drilling rigs with over 75% of those running multiple dual fuel powered drilling rigs. During April, we invoiced a record $1 million in oil and gas related revenue based on previously announced and new orders." Mr. Jensen added, "At a time when global diesel prices continue to escalate, the ability for oil rig operators to use our dual fuel technology with either inexpensive well-head gas or plentiful domestic natural gas as a supplemental fuel provides a significant competitive advantage over operators running on 100% diesel fuel."

About American Power Group Corporation American Power Group's alternative energy subsidiary, American Power Group, Inc., provides a cost-effective patented Turbocharged Natural Gas™ conversion technology for vehicular, stationary and off-road mobile diesel engines. American Power Group's dual fuel technology is a unique non-invasive energy 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 liquefied natural gas; (2) diesel fuel and compressed natural gas; (3) diesel fuel and pipeline or well-head gas; and (4) diesel fuel and bio-methane, with the flexibility to return to 100% diesel fuel operation at any time. The proprietary technology seamlessly displaces up to 80% of the normal diesel fuel consumption with the average displacement ranging from 40% to 65%. The energized fuel balance is maintained with a proprietary read-only electronic controller system ensuring the engines operate at original equipment manufacturers' specified temperatures and pressures. Installation on a wide variety of engine models and end-market applications require no engine modifications unlike the more expensive invasive fuel-injected systems in the market. See additional information at: www.americanpowergroupinc.com .

Caution Regarding Forward-Looking Statements and Opinions With the exception of the historical information contained in this release, the matters described herein contain forward-looking statements and opinions, including, but not limited to, statements relating to new markets, development and introduction of new products, and financial and operating projections. These forward-looking statements and opinions are neither promises nor guarantees, but involve risk and uncertainties that may individually or mutually impact the matters herein, and cause actual results, events and performance to differ materially from such forward-looking statements and opinions. These risk factors include, but are not limited to, results of future operations, difficulties or delays in developing or introducing new products and keeping them on the market, the results of future research, lack of product demand and market acceptance for current and future products, adverse events, product changes, the effect of economic conditions, the impact of competitive products and pricing, governmental regulations with respect to emissions, including whether EPA approval will be obtained for future products and additional applications, the results of litigation, factors affecting the Company's future income and resulting ability to utilize its NOLs, and/or other factors, which are detailed from time to time in the Company's SEC reports, including the report on Form 10-K for the year ended September 30, 2012 and the Company's quarterly reports on Form 10-Q. Readers are cautioned not to place undue reliance on these forward-looking statements and opinions, which speak only as of the date hereof. The Company undertakes no obligation to release publicly the result of any revisions to these forward-looking statements and opinions that may be made to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events.