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 * ELLIS ALEXANDER III   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 __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O ROCKPORT CAPITAL PARTNERS, LP, 160 FEDERAL STREET, 18TH FLOOR 3. Date of Earliest Transaction (Month/Day/Year) 10/15/2010 (Street) BOSTON, MA 02110 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) ___ Form filed by One Reporting Person _X_ 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   J   375,853 (1) A $ 0 (1) 375,853 D (2)   Common Stock 10/15/2010   J   26,842 (1) A $ 0 (1) 402,695 D (3)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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

Warrants

$ 7.92

10/15/2010

J

40,220 (1)

10/15/2010

(4)

Common Stock

40,220

$ 0

40,220

D (2)

Warrants

$ 7.92

10/15/2010

J

15,108 (1)

10/15/2010

(4)

Common Stock

15,108

$ 0

55,328

D (3)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
ELLIS ALEXANDER III C/O ROCKPORT CAPITAL PARTNERS, LP 160 FEDERAL STREET, 18TH FLOOR BOSTON, MA 02110	X	X
RockPort Capital Partners, L.P. 160 FEDERAL STREET, 18TH FLOOR BOSTON, MA 02110	X	X
ROCKPORT CAPITAL I LLC 160 FEDERAL STREET, 18TH FLOOR BOSTON, MA 02110	X	X
RP Co-Investment Fund I, L.P. 160 FEDERAL STREET, 18TH FLOOR BOSTON, MA 02110	X	X
RP Co-Investment Fund I GP, LLC 160 FEDERAL STREET, 18TH FLOOR BOSTON, MA 02110	X	X
James Janet Burrows 160 FEDERAL STREET, 18TH FLOOR BOSTON, MA 02110	X	X
JAMES WILLIAM E 160 FEDERAL STREET, 18TH FLOOR BOSTON, MA 02110	X	X
MCDERMOTT CHARLES J 160 FEDERAL STREET, 18TH FLOOR BOSTON, MA 02110	X	X
Prend David J 160 FEDERAL STREET, 18TH FLOOR BOSTON, MA 02110	X	X
Wilson Stoddard Moran 160 FEDERAL STREET, 18TH FLOOR BOSTON, MA 02110	X	X

Signatures

ALEXANDER ELLIS III, By: /s/ Tom Scott, Attorney-in-Fact		10/19/2010
**Signature of Reporting Person		Date
ROCKPORT CAPITAL PARTNERS, LP, By: Rockport Capital I, LLC, General Partner, By: /s/ Tom Scott, Attorney-in-Fact		10/19/2010
**Signature of Reporting Person		Date
RP CO-INVESTMENT FUND I, L.P., By: RP Co-Investment Fund I GP, LLC, By: /s/ Tom Scott, Attorney-in-Fact		10/19/2010
**Signature of Reporting Person		Date
ROCKPORT CAPITAL I, LLC, By: /s/ Tom Scott, Attorney-in-Fact		10/19/2010
**Signature of Reporting Person		Date
RP CO-INVESTMENT FUND I GP, LLC, By: /s/ Tom Scott, Attorney-in-Fact		10/19/2010
**Signature of Reporting Person		Date
JANET B. JAMES, By: /s/ Tom Scott, Attorney-in-Fact		10/19/2010
**Signature of Reporting Person		Date
WILLIAM E. JAMES, By: /s/ Tom Scott, Attorney-in-Fact		10/19/2010
**Signature of Reporting Person		Date
CHARLES J. MCDERMOTT, By: /s/ Tom Scott, Attorney-in-Fact		10/19/2010
**Signature of Reporting Person		Date
DAVID J. PREND, By: /s/ Tom Scott, Attorney-in-Fact		10/19/2010
**Signature of Reporting Person		Date
STODDARD M. WILSON, By: /s/ Tom Scott, Attorney-in-Fact		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)	This filing is being made as the result of the acquisition of securities of Clean Diesel Technologies, Inc. ("CDTI") by RockPort Capital Partners, L.P. and RP Co-Investment Fund I, L.P. in exchange for securities of Catalytic Solutions, Inc. ("CSI") previously held thereby, pursuant to the merger (the "Merger") of a wholly owned subsidiary of CDTI into CSI on October 15, 2010. As a result of the Merger, CSI became a wholly owned subsidiary of CDTIl. The reporting persons owned no securities of CDTI prior to the Merger.
(2)	Such securities are held directly by RockPort Capital Partners, L.P., and may be deemed to be beneficially owned by RockPort Capital I, LLC, the general partner of RockPort Capital Partners, L.P, and by Alexander Ellis III, Janet B. James, William E. James, Charles J. McDermott, David J. Prend and Stoddard M. Wilson, who are the managing members of RockPort Capital I, LLC. All such persons other than RockPort Capital Partners, L.P. disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that such reporting person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.
(3)	Such securities are held directly by RP Co-Investment Fund I, L.P. , and may be deemed to be beneficially owned by RP Co-Investment Fund I GP, LLC, the general partner of RP Co-Investment Fund I, L.P., and by Alexander Ellis III, Janet B. James, William E. James, Charles J. McDermott, David J. Prend and Stoddard M. Wilson, who are the managing members of RP Co-Investment Fund I GP, LLC. All such persons other than RP Co-Investment Fund I, L.P. disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein, and this report shall not be deemed an admission that such reporting person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.
(4)	The warrants expire on the earlier of (a) October 10, 2013 and (b) the date 30 days after CDTI notifies the warrant holder that the market price of CDTI's common stock has exceeded $10.30 for 10 consecutive days.

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