RNS Number:2386L
Clean Diesel Technologies, Inc
16 May 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 May 19, 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 (investors)          James M. Valentine, President
          (212) 691-8087                      David W. Whitwell, CFO
          jay@allencaron.com                  (203) 327-7050
          Len Hall (media)
          (949) 474-4300
          len@allencaron.com              
                                            
                       
                     
CLEAN DIESEL TECHNOLOGIES AND MITSUI TEAM TO VERIFY NEW DIESEL PARTICULATE
             FILTER AND FUEL BORNE CATALYST SYSTEM

CDT to Manage Engine and Field Trials, Mitsui to Support Verification Tests

STAMFORD, CT (May 19, 2003) ... Clean Diesel Technologies, Inc. (CDT) (EBB:CDTI
& AIM:CDT/CDTS)  announced today that it has signed a second Memorandum of
Understanding (MOU) with Mitsui and Co. and Mitsui's PUREarth Inc. subsidiary to
commence field testing and retrofit verification of a PUREarth  catalyzed wire
mesh filter (CWMF) designed for use with CDT's Platinum Plus(R) fuel borne
catalyst (FBC). Initially the CWMF will be manufactured by Mitsui in Japan with
application engineering and marketing handled in the US by CDT.  CDT will also
be responsible for managing the California Air Resources Board (CARB) and EPA
verification programs with funding from Mitsui/ PUREarth. Together the companies
will be looking for potential marketing and distribution partners in the US to
address both the retrofit and new vehicle markets for diesel particulate
reductions.


          Under an earlier MOU the companies had completed engine testing at
Southwest Research Institute (SwRI), which demonstrated the ability of Mitsui's
CWMF and CDT's FBC to achieve 65 percent particulate matter (PM) reduction along
with reductions in HC and CO of over 80 percent while meeting the CARB limit of
20 percent NO2 in the exhaust.  Testing was conducted on a 1990 medium
heavy-duty engine typical of school bus and local delivery fleets.


          James M. Valentine, President of CDT, said, "The performance of the
FBC/CWMF system provides solid Level 2 reductions in particulates under CARB's
Diesel Risk Reduction Program.  We are currently arranging installation of
devices on refuse and beverage-delivery trucks that are already using Platinum
Plus treated fuel for fuel economy and emissions reduction.  This type of
service represents some of the toughest applications for filters due to the
stop-and-go duty cycle and low exhaust temperatures which tend to plug
traditional filters.  These field data will be used along with engine test
results to support verification with CARB and EPA."


According to Valentine, the Platinum Plus FBC reduces engine-out emissions by
15-30 percent by promoting more complete in-cylinder combustion; and the
specially catalyzed wire mesh filter captures the remaining particulate which is
then oxidized by the presence of catalyst on the filter surface and catalyst
from the FBC which is tightly bound in the soot.  This dual action approach to
soot oxidation allows for very low temperature operation without the plugging
problems of other filter designs.  Many of the traditional high efficiency DPFs
can only operate on new, cleaner engines, with high exhaust temperature.

                                 MORE-MORE-MORE

CLEAN DIESEL TECHNOLOGIES TEAMS WITH MITSUI TO VERIFY NEW DIESEL PARTICULATE
FILTER AND FBC SYSTEM

Page 2-2-2


Traditional heavily catalyzed devices not only cost twice as much, but they also
tend to dramatically increase NO2 in the exhaust gas.  NO2 is a strong lung
irritant and is regulated by the Mining Safety Health Administration in
underground mines and by CARB for diesel retrofit technologies.



         CARB has proposed regulations to control diesel PM from more than
1.2 million existing engines and the FBC/CWMF fills the void left by low
efficiency DOCs (20-25 percent) and high cost traditional DPFs.  CARB recently
issued a technical assessment document which cites the CDT approach as one of
the technologies likely to be broadly applicable to refuse trucks.  The FBC/CWMF
system should also be attractive to school bus and private delivery fleets under
EPA's voluntary diesel retrofit program, who will recognize that 65 percent
reduction from a high emissions ten year old vehicle is a lot more reduction
than 85 percent from a new and relatively clean engine.


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 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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