RNS Number:2178Q
Clean Diesel Technologies, Inc
29 September 2003


                                                                Clean Diesel Technologies, Inc.

300 Atlantic Street, Suite 702, Stamford, CT 06901-2522 Tel: (203) 327-7050 Fax: (203) 323-0461


NEWS RELEASE for September 29, 2003 at 2:30 am EDT and 7:30 am GMT (London time)

Contact:           Allen & Caron Inc                  or        Clean Diesel Technologies, Inc.
                   Jay F. McKeage (US investors)                James M. Valentine, President
                  (212) 691-8087; jay@allencaron.com  David W. Whitwell, CFO
                   Len Hall (US media)                         (203) 327-7050
                  (949) 474-4300; len@allencaron.com
                   Bankside Consultants
                   Simon Bloomfield (UK media/investors)
                   44 (0)20 7444 4140;  simon.bloomfield@bankside.com


CLEAN DIESEL TECHNOLOGIES SIGNS COMMITMENT LETTER WITH MITSUI SUBSIDIARY TO
PARTICIPATE IN $3.8 MILLION FINANCING

Expands Strategic Partnership for Diesel Emissions Control


STAMFORD, CT (September 29 , 2003) ... Clean Diesel Technologies, Inc. (CDT)
(EBB:CDTI & AIM:CDT/CDTS) announced today that Mitsui & Co. Ltd's subsidiary PUREarth Inc.
has  participated in the recently announced $3.8 million private placement of
CDT's common stock along with several UK based shareholders.

According to James Valentine, President & COO of CDT, "We are delighted with the
equity investment by PUREarth in CDT.  It reflects the growing strength of the
mutual relationship between CDT and Mitsui which started with the ARIS Urea SCR
NOx Reduction technology and has expanded to our combined efforts to
commercialize CDT's fuel-borne catalyst (FBC) technology using PUREarth's
catalyzed wire mesh filter (CWMF).  As a result, once we have achieved the
verifications required, we will be in a strong position to generate significant
revenues in the US diesel engine retrofit market."

            CDT and PUREarth have been working since December 2002 on several
programs to verify the emissions reduction performance of PUREarth's CWMF and
CDT's Platinum Plus(R) FBC.  Two separate engine test programs conducted at
Southwest Research Institute (SwRI) have shown particulate reductions of 65 to
70 percent with hydrocarbons (HC) and carbon monoxide(CO) reductions of over 75
percent.  The greater than 50 percent reduction in particulate matter would
qualify as a level two verification under the California Air Resources Board
(CARB) Diesel Risk Reduction program targeting retrofit controls to over 1.2
million engines.  In addition, emissions of nitrogen dioxide (NO2) have been
minimized by specifically designing the CWMF to operate with FBC-treated fuel.
Traditional heavily catalyzed filter systems can cause dramatic increase in NO2
which is a strong lung irritant.  Besides the emissions tests, the companies
have completed a 225-hour accelerated durability test of the system at SwRI
representing about 500 hours of local delivery service.  Performance of the
system was maintained even over the aggressive durability test cycle.

Several FBC/CWMF systems have been placed in commercial service on refuse trucks
in California and beverage delivery trucks in Texas using automatically dosed
FBC-treated fuel.  These applications represent the toughest conditions for a
filter due to low exhaust temperatures and higher soot emissions from older,
dirtier engines built in 1990-1993.  The FBC reduces engine-out



MORE-MORE-MORE



CLEAN DIESEL SIGNS COMMITMENT LETTER WITH MITSUI SUBSIDIARY

Page 2-2-2



soot by 15-25 percent and assists in further oxidizing soot that collects in the
specially catalyzed CWMF.  This prevents plugging of the filter with soot even
at low exhaust temperatures.  Following the required 1,000 hours of field service, 
units will be retested at SwRI to support verification under EPA and CARB 
programs.  Testing is planned for fourth quarter 2003.  Proceeds from the recent 
fundraising will be used to support verification programs and for sales, 
technical services and other commercial activities.

Under a previously announced Memorandum of Understanding, initially
PUREarth will manufacture the CWMF devices in Japan and CDT will provide
application engineering and marketing in the US, as well as selling and
distributing the FBC.  CDT is also managing the CARB and EPA verification
programs.  CDT and PUREarth are continuing discussions with several potential
marketing and distribution partners in the US to address both the retrofit and
new vehicle market for diesel particulate reduction.

To begin with the FBC/CWMF system will be targeted at school bus fleets,
delivery vehicles and refuse trucks.  It will provide a lower cost solution to
end users without the excessive NO2 generation that characterizes traditional
heavily catalyzed systems.

About Mitsui & Co., Ltd.

Mitsui & Co., Ltd. is one of world's largest and most diversified international
trading companies, with business extending from chemicals to steel and metals to
transportation machinery.  Its Inorganic Chemical Group, together with a unit of
Mitsui & Co.(USA), Inc., Mitsui's wholly-owned U.S. subsidiary headquartered in
New York City, is working with several industrial partners active in
engineering, fuels and heavy-duty vehicles to address diesel engine emissions in
Japan.  Mitsui has formed a wholly owned subsidiary, PUREarth to address diesel
particulate emissions and has a 50 percent ownership in Denox Inc. focused on
diesel NOx control.  Mitsui also holds the exclusive license on CDT's ARIS NOx
control technology for Japan.

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(R) fuel
catalysts and the ARIS(R) 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 contact Clean Diesel Technologies directly, or visit their
web site at www.cdti.com.


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.

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            The company news service from the London Stock Exchange
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