FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * Engles Charles Robert   2. Issuer Name and Ticker or Trading Symbol CLEAN DIESEL TECHNOLOGIES INC [CDTI] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O CLEAN DIESEL TECHNOLOGIES, INC., 4567 TELEPHONE ROAD, SUITE 206 3. Date of Earliest Transaction (Month/Day/Year) 10/15/2010 (Street) VENTURA, CA 93003 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common stock 10/15/2010   A   13,229 (1) A $ 0 (2) 13,229 (1) D

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Common stock warrants (right to buy)

$ 7.92 (1)

10/15/2010

A

10,825 (1)

10/15/2010

10/15/2013(3)

Common stock

10,825 (1)

$ 0 (2)

10,825 (1)

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Engles Charles Robert C/O CLEAN DIESEL TECHNOLOGIES, INC. 4567 TELEPHONE ROAD, SUITE 206 VENTURA, CA 93003	X

Signatures

/s/ Kristi Cushing for Charles Robert Engles		10/19/2010
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	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.
(2)	Received in exchange for 1,677,317 shares of Class A common stock of Catalytic Solutions, Inc. ("CSI") in connection with the business combination of Clean Diesel Technologies, Inc. ("CDTI") and CSI in which a subsidiary of CDTI merged with and into CSI (the "Merger").
(3)	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.

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