SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* ELLIS ALEXANDER III (Last) (First) (Middle) C/O ROCKPORT CAPITAL PARTNERS, LP 160 FEDERAL STREET, 18TH FLOOR (Street) BOSTON MA 02110 (City) (State) (Zip)	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)
	3. Date of Earliest Transaction (Month/Day/Year) 10/15/2010
	4. If Amendment, Date of 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

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)

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 Securities Underlying Derivative Security (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: 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)

1. Name and Address of Reporting Person* ELLIS ALEXANDER III (Last) (First) (Middle) C/O ROCKPORT CAPITAL PARTNERS, LP 160 FEDERAL STREET, 18TH FLOOR (Street) BOSTON MA 02110 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* RockPort Capital Partners, L.P. (Last) (First) (Middle) 160 FEDERAL STREET, 18TH FLOOR (Street) BOSTON MA 02110 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ROCKPORT CAPITAL I LLC (Last) (First) (Middle) 160 FEDERAL STREET, 18TH FLOOR (Street) BOSTON MA 02110 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* RP Co-Investment Fund I, L.P. (Last) (First) (Middle) 160 FEDERAL STREET, 18TH FLOOR (Street) BOSTON MA 02110 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* RP Co-Investment Fund I GP, LLC (Last) (First) (Middle) 160 FEDERAL STREET, 18TH FLOOR (Street) BOSTON MA 02110 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* James Janet Burrows (Last) (First) (Middle) 160 FEDERAL STREET, 18TH FLOOR (Street) BOSTON MA 02110 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* JAMES WILLIAM E (Last) (First) (Middle) 160 FEDERAL STREET, 18TH FLOOR (Street) BOSTON MA 02110 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MCDERMOTT CHARLES J (Last) (First) (Middle) 160 FEDERAL STREET, 18TH FLOOR (Street) BOSTON MA 02110 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Prend David J (Last) (First) (Middle) 160 FEDERAL STREET, 18TH FLOOR (Street) BOSTON MA 02110 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Wilson Stoddard Moran (Last) (First) (Middle) 160 FEDERAL STREET, 18TH FLOOR (Street) BOSTON MA 02110 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer X Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

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.

Remarks:

	ALEXANDER ELLIS III, By: /s/ Tom Scott, Attorney-in-Fact	10/19/2010
	ROCKPORT CAPITAL PARTNERS, LP, By: Rockport Capital I, LLC, General Partner, By: /s/ Tom Scott, Attorney-in-Fact	10/19/2010
	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
	ROCKPORT CAPITAL I, LLC, By: /s/ Tom Scott, Attorney-in-Fact	10/19/2010
	RP CO-INVESTMENT FUND I GP, LLC, By: /s/ Tom Scott, Attorney-in-Fact	10/19/2010
	JANET B. JAMES, By: /s/ Tom Scott, Attorney-in-Fact	10/19/2010
	WILLIAM E. JAMES, By: /s/ Tom Scott, Attorney-in-Fact	10/19/2010
	CHARLES J. MCDERMOTT, By: /s/ Tom Scott, Attorney-in-Fact	10/19/2010
	DAVID J. PREND, By: /s/ Tom Scott, Attorney-in-Fact	10/19/2010
	STODDARD M. WILSON, By: /s/ Tom Scott, Attorney-in-Fact	10/19/2010
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* 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).
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