-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001209191-10-050949.txt : 20101019
<SEC-HEADER>0001209191-10-050949.hdr.sgml : 20101019
<ACCEPTANCE-DATETIME>20101019162239
ACCESSION NUMBER:		0001209191-10-050949
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101015
FILED AS OF DATE:		20101019
DATE AS OF CHANGE:		20101019

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Engles Charles Robert
		CENTRAL INDEX KEY:			0001503473

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33710
		FILM NUMBER:		101130605

	MAIL ADDRESS:	
		STREET 1:		C/O CLEAN DIESEL TECHNOLOGIES, INC.
		STREET 2:		4567 TELEPHONE ROAD, SUITE 206
		CITY:			VENTURA
		STATE:			CA
		ZIP:			93003

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CLEAN DIESEL TECHNOLOGIES INC
		CENTRAL INDEX KEY:			0000949428
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL INORGANIC CHEMICALS [2810]
		IRS NUMBER:				061393453
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		10 MIDDLE STREET
		STREET 2:		SUITE 1100
		CITY:			BRIDGEPORT
		STATE:			CT
		ZIP:			06604
		BUSINESS PHONE:		2034165290

	MAIL ADDRESS:	
		STREET 1:		10 MIDDLE STREET
		STREET 2:		SUITE 1100
		CITY:			BRIDGEPORT
		STATE:			CT
		ZIP:			06604
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c07013_4x0.xml
<DESCRIPTION>MAIN DOCUMENT DESCRIPTION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-10-15</periodOfReport>

    <issuer>
        <issuerCik>0000949428</issuerCik>
        <issuerName>CLEAN DIESEL TECHNOLOGIES INC</issuerName>
        <issuerTradingSymbol>CDTI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001503473</rptOwnerCik>
            <rptOwnerName>Engles Charles Robert</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CLEAN DIESEL TECHNOLOGIES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>4567 TELEPHONE ROAD, SUITE 206</rptOwnerStreet2>
            <rptOwnerCity>VENTURA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>93003</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-10-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>13229</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13229</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Common stock warrants (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>7.92</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-10-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10825</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2010-10-15</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-10-15</value>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10825</value>
                    <footnoteId id="F1"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10825</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Amount and/or exercise price reflect the one for six reverse stock split of the issuer's common stock that took effect October 15, 2010.</footnote>
        <footnote id="F2">Received in exchange for 1,677,317 shares of Class A common stock of Catalytic Solutions, Inc. (&quot;CSI&quot;) in connection with the business combination of Clean Diesel Technologies, Inc. (&quot;CDTI&quot;) and CSI in which a subsidiary of CDTI merged with and into CSI (the &quot;Merger&quot;).</footnote>
        <footnote id="F3">The warrants will expire on the earlier of (i) the third anniversary of the effective time of the Merger and (ii) the date that is 30 days after CDTI gives notice to the warrant holder that the market value of one share of CDTI common stock has exceeded 130% of the exercise price of the warrant for 10 consecutive days.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Kristi Cushing for Charles Robert Engles</signatureName>
        <signatureDate>2010-10-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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