Clean Diesel Announces Receipt of EPA Verification of New Platinum Plus® Purifier Diesel Retrofit System

Results Indicate Dramatic Reduction in Diesel Particulates

STAMFORD, CT (October 13, 2003) . . . Clean Diesel Technologies, Inc. (CDT) (EBB:CDTI & AIM:CDT/CDTS) announced today that it has received notification from the US Environmental Protection Agency of verification of emissions reduction performance of its Platinum Plus® Purifier System for retrofit to 1988-1993 diesel engines. Rigorous engine dynamometer testing of the Platinum Plus Purifier System after 1,000 hours of commercial service shows that the system more than doubles the particulate matter (PM) reduction offered by traditional diesel oxidation catalysts (DOCs) currently in use, without increasing nitrogen dioxide (NO2) emissions.

Reductions of 40-50 percent in PM emissions were measured at Southwest Research Institute (SwRI) on a 1991 certified Cummins medium heavy-duty diesel engine typical of those used in school buses, municipal buses, delivery trucks and refuse haulers. These reductions were verified by the EPA under its rigorous Environmental Technology Verification (ETV) test protocol. This high level of PM reduction was achieved from use of the Platinum Plus fuel-borne catalyst (FBC) and a low-cost, specially catalyzed DOC used with commercial No. 2D fuel and also with ultra-low sulfur diesel (ULSD) fuel. Verification of the Platinum Plus Purifier System is now posted on the EPA web site at www.epa.gov/otaq/retrofit/retroverifiedlist.htm.

Verification follows recent field trials with beverage delivery trucks used in commercial service in Texas as well as with refuse trucks in California. In these programs the combination of Platinum Plus FBC and DOC purifier system was demonstrated effective even in aggressive stop-and-go delivery service. Reductions of 41percent were verified for application with normal No. 2D fuel and up to 50% with ULSD.

Commenting on the verification, James Valentine, CDT President and Chief Operating Officer, said, “Most other traditional DOCs give only 20-25 percent PM reduction and can cause large increases in NO2 emissions, which, as a strong ground-level lung irritant, are restricted by the California Air Resources Board (CARB) and the Mining Safety Health Administration (MSHA). In comparison with traditional, heavily-catalyzed devices, the Platinum Plus Purifier System uses only a fraction of the precious metals, by putting the catalyst in the fuel as well as on the lightly- catalyzed DOC device. This dual-action approach reduces more PM at lower costs without any increase in NO2 emissions. In fact, NO2 emissions are lowered with the system by up to 40 percent.”

“This patented combination technology maximizes engine performance and minimizes the cost of compliance,” Valentine continued. “CDT has invested over a million dollars in more than 100 tests at SwRI to separate the impact on emissions of fuels, the FBC and catalytic devices, in order to optimize the system’s performance and minimize unwanted NO2 emissions.”

“With the Platinum Plus Purifier System, fleets can start tomorrow with fuel currently in use and get 40 percent PM reduction, knowing that reductions will improve to as much as 50 percent when they switch to ULSD as it becomes economically available. In addition, over a dozen fleet trials have confirmed an average of 8 percent fuel economy improvement from regular use of the FBC, which more than pays for the FBC and helps offset the cost of the lightly-catalyzed DOC.”

The system should be especially attractive to local delivery fleets and school buses with older, dirtier engines. Typical retrofit capital costs for the Platinum Plus Purifier System could allow as many as five school buses to be retrofitted, versus one vehicle retrofitted for the same cost with a traditional, heavily-catalyzed particulate filter.

CDT intends to supply verified systems directly to end-users and through a planned network of licensed distributors. The Platinum Plus FBC can be delivered pre-blended in fuel by licensed fuel suppliers, or added to fuel on-site by end-users using automatic dosing systems. Several on-board dosing systems are also under development.

About Clean Diesel Technologies, Inc.

Clean Diesel Technologies, Inc. is a specialty chemical company with patented products that reduce emissions from diesel engines while simultaneously improving fuel economy and power. Products include Platinum Plus® fuel catalysts, the Platinum Plus Purifier System, and the ARIS® 2000 urea injection systems for selective catalytic reduction of NOx. Platinum Plus and ARIS are registered trademarks of Clean Diesel Technologies, Inc. For more information, visit CDT at www.cdti.com or contact the Company directly.

Certain statements in this news release constitute “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements involve known or unknown risks, including those detailed in the Company’s filings with the Securities and Exchange Commission, uncertainties and other factors which may cause the actual results, performance or achievements of the Company, or industry results, to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof.