Exhibit 10.15
                                    AMENDMENT

      This Amendment dated this 1st day of April, 2004 by and among Coates
International, Ltd., having a business address at Highway 34 and Ridgewood Road,
Wall Township, New Jersey 07719-0738, and George Coates, having an address at
Highway 34 and Ridgewood Road, Wall Township, New Jersey 07719-9738 (the above
identified parties are collectively referred to as the "Licensor") and McLean,
England and Associates, LLC, having its principal offices located at One Innwood
Circle, Suite 2004, Little Rock, Arkansas 72211 (the "Licensee").

      WHEREAS, Licensor and Licensee entered into a License Agreement originally
on April 12, 2002 and have operated pursuant to their agreement through the date
of this Amendment ("License Agreement");

      WHEREAS, Licensor has retrofitted the No.1 Diesel 855 engine incorporating
the Coates CSRV System, which engine is operational on a test stand. This engine
is not ready for final testing and many costly modifications are to be carried
out before it is ready for final testing.

      WHEREAS, Licensee has requested Licensor to retrofit another 855 No. 2
engine to gasoline incorporating the CSRV by doing so has placed an extra
expense and burden on Licensor. Currently, it is not financially feasible for
Licensor to complete both engines concurrently without considerable additional
funding and staff.

      WHEREAS, in the interest of time and efficiency Licensor and Licensee have
agreed to allow Licensee at its own expense to undertake various modifications
and refinements to the No. 1 855 Diesel powered CSRV truck engine;

      WHEREAS, in order to accomplish the aforesaid mutual objective of Licensor
and Licensee, it is necessary to supplement the License Agreement solely as
specified in, and limited by, this Amendment. The permission granted by Licensor
pursuant to this Amendment is not intend to, and does not constitute a novation
of the License Agreement.

      NOW, THEREFORE, in consideration of the premises and covenants, and other
good and valuable consideration, and the mutual promises of the performance of
the undertaking set forth in the License Agreement and in this Amendment, it is
agreed, by and among Licensor and Licensee, as follows:

      1.    DEFINED TERMS. Except as specifically defined herein, all
            definitions of terms used herein shall be in accordance with the
            License Agreement.

      2.    POSSESSION. For the limited purpose set forth in paragraph 6 below,
            Licensor shall permit Licensee to take possession of, but not title
            to, and to remove from Licensor's business premises, a single diesel
            powered internal combustion engine that Licensor has retro-fitted
            with the CSRV Valve System ("No. 1 Test Engine") together with one
            of the two trucks containing an 855 Cummins Engine owned by Licensee
            ("Test Truck"). Unless or until otherwise specified in the License
            Agreement, Licensor shall retain title to the Test Engine, with
            exception of the trucks which are the property of Licensee. The
            parties agree that the Test Engine is currently in a state of
            development, which Licensee will attempt to refine. The Test Engine
            is not ready for testing and certification, and does not constitute
            a delivery of such an engine as contemplated by the Confidential
            Addendum to the License Agreement.

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      3.    TEST MATERIAL. Licensor shall provide Licensee with, but not title
            to, the Test Engine on test stand, all related drawings or other
            intellectual property, that Licensor feels would aid Licensee in its
            refinement efforts (collectively the "Test Material"). If Licensee
            requires any parts from Licensor, Licensee must pay for parts made
            by Licensor.

      4.    SHIPPING. Licensee shall be responsible for packing, crating,
            shipping and transporting the Test Material and all costs associated
            therewith. Licensee shall be responsible for all damage from
            whatever cause or source caused to the Test Material, while the Test
            Material is off of Licensor's business premises. Within five (5)
            days of taking possession of the Test Material Licensee shall
            deliver the Test Material to Ram Industries 7200 Industry Dr., North
            Little Rock, 72117 ("Ram Premises").

      5.    INSURANCE. Licensee shall insure the Test Material against all
            damage and loss for its full replacement value which is currently
            estimated to be $250,000 with Licensor named as the sole loss payee;
            Licensor calculates it has expended approximately $2,500,000.00 on
            Licensee's Diesel 855 engine. Moreover, Licensee shall provide
            Licensor with an insurance policy providing general comprehensive
            liability coverage for Licensor in relation to the Test Material
            that meets the specifications of the License Agreement. The
            insurance policy(ies) shall be delivered by Licensee to Licensor
            before the Test Material is removed from Licensor's business
            premises. Each insurance policy shall be issued by an insurance
            company that is reasonably acceptable to Licensor and which is
            authorized to do business both in the State of New Jersey and in the
            State of Arkansas.

      6.    PURPOSE. Licensor grants its permission for Licensee at its own
            expense to use third party firms in its refinement efforts, which
            will be required to protect the confidentiality of Licensor's
            patents and trade secrets; each such consultant shall be required to
            sign a confidentiality agreement. The required confidentiality
            agreement is attached hereto as Exhibit A ("Confidentiality
            Agreement"). Licensee shall be responsible to enforce the
            Confidentiality Agreement and shall indemnify the Licensor against
            any loss associated with a breach of the Confidentiality Agreement
            caused by, or related to, an act or omission of Licensee. Licensor
            will be the owner of all work and improvements made by Licensee and
            its third party contractors. Licensee's efforts are intended to
            supplement those of Licensor and to accelerate the time when the
            Test Engine can be tested at Southwest Research Institute for EPA
            certification purposes. Licensor, however, without having any
            obligation to do so, may, in its sole and absolute discretion,
            continue to work on the No. 2 gasoline engine project to completion.

      7.    PAYMENT. All payments due Licensor by Licensee shall become due, and
            will be paid, in accordance with the License Agreement, except that
            if Licensee through its efforts produces an engine that satisfies
            the criteria specified in the License then the precondition to
            Licensee's payment obligation shall have been satisfied as if the
            Licensor had produced an engine that satisfied the criteria
            specified in the License and payment shall be due from the Licensee
            pursuant to the terms of the License Agreement.

      8.    REPORTS. Licensee shall provide Licensor with a written progress
            report every fifteen (15) days detailing the progress that is being
            made on the Test Engine.

      9.    LOCATION. Licensee shall not remove the Test Material from the Ram
            Premises without the prior written approval of the Licensor.
            Licensor and its agents, employees, contractors and consultants, on
            two (2) business days notice, shall have the absolute right, but not
            the obligation, to enter the Ram Premises, during normal business
            hours, to inspect the Test Engine and/or the Test Truck and all
            related data, plans, results, reports and documents relating to the
            Test Engine and/or the Test Truck.

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            Licensee represents to Licensor that the Ram Premises are safe and
            secure and that access to the Test Material will be limited to the
            Licensee and its consultant which access shall be governed by the
            terms of the Confidentiality Agreement.

      10.   INDEMNIFICATION. Indemnification between the parties will be in
            accordance with the License Agreement and paragraphs 4, 6 and 9
            hereof.

      11.   CONFIDENTIALITY. The confidentiality of Licensor's patents and trade
            secretes shall be maintained in accordance with the License
            Agreement and paragraphs 6 and 9 hereof.

      12.   BREACH; REMEDIES. In the event of a breach by either party of this
            Amendment the remedies of the parties shall be governed in
            accordance with the License Agreement.

      13.   NOTICES. All notices between the parties shall be made in accordance
            with License Agreement.

      14.   APPLICABLE LAW. The law applicable to this Amendment Agreement shall
            be in accordance with License Agreement.

      15.   SEVERABILITY. If any term, covenant, condition or provision of this
            Amendment, or the application thereof to any person or circumstance,
            shall, at any time or to any extent, be invalid or unenforceable,
            the remainder of this Amendment, or the application of such term or
            provision to persons or circumstances other than those as to which
            it is held invalid or unenforceable, shall not be affected thereby,
            and each term, covenant, condition and provision of this Amendment
            shall be valid and be enforced to the fullest extent permitted by
            law.

      16.   INTERPRETATION. Wherever herein the singular number is used, the
            same shall include the plural, and the masculine gender shall
            include the feminine and neuter genders, and vice versa, as the
            context shall require.

      17.   COUNTERPARTS. This Amendment may be executed in several
            counterparts, each of which shall be an original, but all of which
            shall constitute one and the same instrument.

      18.   SECTION HEADINGS. The section headings in this Amendment are
            inserted only as a matter of convenience in reference and are not to
            be given any effect whatsoever in construing any provision of this
            Amendment.

      19.   ASSIGNMENT. Neither this Amendment nor the License Agreement may be
            assigned by Licensee except as permitted by the License Agreement.

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ATTEST:                                COATES INTERNATIONAL, LTD.

/s/ Shirley Naidel                     BY:  /s/ George J. Coates
------------------------------------        ---------------------------
Shirley Naidel                              George J. Coates, President
Notary Public - New Jersey
My Commission Expires Dec. 27, 2005
as to Both Signatures of
George J. Coates

/s/ Shirley Naidel                          /s/ George J. Coates
----------------------                      ------------------------------
Shirley Naidel                              George J. Coates, Individually

ATTEST:                                McLEAN, ENGLAND & ASSOCIATES, LLC

(Illegible)                            By:  /s/ Jeff England
----------------------                      ----------------
                                            Jeff England