DEBENTURE AGREEMENT

THE SECURITIES OFFERED HEREBY HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT
OF 1933, AS AMENDED, OR ANY STATE SECURITIES LAWS AND ARE BEING OFFERED AND SOLD
IN RELIANCE ON EXEMPTIONS FROM THE REGISTRATION REQUIREMENTS OF SUCH LAWS. THE
SECURITIES ARE SUBJECT TO RESTRICTIONS OF TRANSFERABILITY AND RESALE AND MAY NOT
BE TRANSFERRED OR RESOLD EXCEPT AS PERMITTED UNDER SUCH LAWS PURSUANT TO
REGISTRATION OR AN EXEMPTION THEREFROM. THE SECURITIES HAVE NOT BEEN APPROVED OR
DISAPPROVED BY THE SECURITIES AND EXCHANGE COMMISSION OR ANY OTHER REGULATORY
AUTHORITY, NOR HAVE ANY OF THE FOREGOING AUTHORITIES PASSED UPON OR ENDORSED THE
MERITS OF THIS OFFERING OR THE ACCURACY OR ADEQUACY OF THE OFFERING MATERIALS.
ANY REPRESENTATION TO THE CONTRARY IS UNLAWFUL.

FACE AMOUNT                               $340,000
PRICE                                     $340,000
DEBENTURE NUMBER                          November - 2005-101
ISSUANCE DATE                             November 4, 2005
MATURITY DATE                             November 4, 2010

      FOR VALUE RECEIVED, Hybrid Fuel Systems, Inc. Corp. a Georgia corporation
(the "Company"), hereby promises to pay DUTCHESS PRIVATE EQUITIES FUND, II, LP
("Holder") by November 4, 2010 (the "Maturity Date"), the principal amount of
Three Hundred and Forty Thousand Dollars ($340,000) U.S., and to pay interest
and redemption on the principal amount hereof, and any accrued penalties
accrued, in such amounts, at such times and on such terms and conditions as are
specified herein.

      The Debenture is subject to automatic conversion at the end of five (5)
years from the date of issuance at which time the Debenture outstanding will be
automatically converted based upon the formula set forth in Section 3.2 (c).

Article 1         Interest

      The Company shall pay twelve percent (12%) annual coupon on the unpaid
Face Amount of this Debenture (the "Debenture") at such times and in such
amounts as outlined in this section. The Company will make mandatory prepaid
payments, in advance, on the interest ("Interest Payment"), with the minimum
Interest Payments outlined in Exhibit B for the first three (3) months, and
herein incorporate by reference in the amount of three thousand three hundred
and sixty-nine dollars and forty-six cents ($3,369.46) per month for the first
three (3) month following Issuance Date. The first Interest Payment is due
within three days of funds being disbursed to the Company (a "Closing:").

      Any monies paid to the Holder in excess of the interest due when paid
shall be credited toward the Face Amount of the Debenture.


                                       1
<PAGE>


Article 2         Method of Payment

      Section 2.1 Prior to the U.S. Securities and Exchange Commission ("SEC")
declaring the registration statement for the shares underlying the Debenture
("Registration Statement") effective ("Effective Date").

            Amortizing payments will be made by the Company in satisfaction of
this Debenture (each a "Payment," and collectively, the "Payments") monthly on
the fourth (4th) day of each business day of each month while there is an
outstanding balance on the Debenture, to the Holder, in the amounts ("Payment
Amount" and collectively, the "Payment Amounts") outlined below on the following
schedule:

Payment for Month 1 (due within three (3) days of the Issuance Date)   $3,369.46
Payment for Month 2 and each month thereafter                         $40,498.44


            Notwithstanding any provision to the contrary in this Debenture, the
Company may pay in full to the Holder the Face Amount, or any balance remaining
thereof, in readily available funds at any time and from time to time without
penalty.

            The minimum Payments are outlined on Exhibit B, attached hereto and
incorporate by reference.

      Section 2.2 Subsequent to the Effective Date.

      The Holder, at its sole option, shall be entitled to either a) request a
Payment from the Company in the amounts set forth in the table in Section 2.1
above; or, b) the Holder may elect to convert a portion of the Debenture
pursuant to Article 3 below in an amount equal to the Payment Amount. In the
event the Holder is unable to convert that portion of the Debenture equal to the
Payment Amount during a calendar month, the Company shall make a payment in an
amount equal to the difference between the amount converted by the Holder and
the Payment Amount due for that month.

      Nothing contained in this Article 2 shall limit the amount the Holder can
elect to convert during a calendar month except as defined in Section 3.2 (i)

      All Payments made in this Article 2, shall be applied toward the
Redemption Amount as outlined in Article 14, herein.

      Section 2.3  Prepayment

      The Company may make additional payments ("Prepayment") without any
penalties. After Closing, the Company must make a Prepayment to the Holder when
the aggregate amount of financing received by the Company is in excess of
$340,000 ("Threshold Amount"). The Company agrees to pay one hundred percent
(100%) of any proceeds raised by the Company over the Threshold Amount toward
the Prepayment of the Debenture with Interest until the Amount is paid in full.
The Prepayments shall be made to the Holder upon the Company's receipt of the
financing. Failure to do so will result in an event of default.


                                       2
<PAGE>

Article 3         Conversion

Section 3.1 Conversion Privilege

            (a) The Holder of this Debenture shall have the right to convert any
and all amounts owing under this Debenture into shares of Common Stock at any
time following the Closing Date and which is before the close of business on the
Maturity Date, except as set forth in Section 3.1(c) below. The number of shares
of Common Stock issuable upon the conversion of this Debenture is determined
pursuant to Section 3.2 and rounding the result to the nearest whole share.

            (b) This Debenture may not be converted, whether in whole or in
part, except in accordance with this Article 3.

            (c) In the event all or any portion of this Debenture remains
outstanding on the Maturity Date, the unconverted portion of such Debenture will
automatically be converted into shares of Common Stock on such date in the
manner set forth in Section 3.2.

Section 3.2 Conversion Procedure.

            (a) Conversion Procedures. The unpaid Face Amount of and accrued
interest on this Debenture may be converted, in whole or in part, any time
following the Closing Date. Such conversion shall be effectuated by sending to
the Company a facsimile or via electronic mail the signed Notice of Conversion
which evidences Holder's intention to convert the Debenture indicated. The date
on which the Notice of Conversion is delivered ("Conversion Date") shall be
deemed to be the date on which the Holder has delivered to the Company a
facsimile of the signed Notice of Conversion. Notwithstanding the above, any
Notice of Conversion received by 5:00 P.M. EST, shall be deemed to have been
received the previous business day, with receipt being via a confirmation of
time of facsimile of the Holder.

            (b) Common Stock to be Issued. Upon the conversion of any Debenture
and upon receipt by the Company of a facsimile of Holder's signed Notice of
Conversion the Company shall instruct its transfer agent to issue stock
certificates without restrictive legend (other than a legend referring to the
registration statement and prospectus delivery requirements) or stop transfer
instructions, if at that time the Registration Statement has been declared
effective (or with proper restrictive legend if the Registration Statement has
not as yet been declared effective), in such denominations to be specified at
conversion representing the number of shares of Common Stock issuable upon such
conversion, as applicable. The Company shall act as Registrar and shall maintain
an appropriate ledger containing the necessary information with respect to each
Debenture. The Company warrants that no instructions, other than these
instructions, have been given or will be given to the transfer agent and that
the Common Stock shall otherwise be freely resold, except as may be set forth
herein.


                                       3
<PAGE>

            (c) Conversion Rate. Holder is entitled to convert the unpaid Face
Amount of this Debenture, plus accrued interest, any time following the Closing
Date, at the lesser of (i) the lowest closing bid price of the Common Stock
between October 18, 2005 and the date of filing the registration statement
covering resale of the shares underlying this Debenture; or (ii) twenty-seven
cents ($.27). ("Fixed Conversion Price"), each being referred to as the
"Conversion Price". No fractional shares or scrip representing fractions of
shares will be issued on conversion, but the number of shares issuable shall be
rounded up, as the case may be, to the nearest whole share. The Holder shall
retain all rights of conversions during any partial trading days.

            (d) Nothing contained in this Debenture shall be deemed to establish
or require the payment of interest to the Holder at a rate in excess of the
maximum rate permitted by governing law. In the event that the rate of interest
required to be paid exceeds the maximum rate permitted by governing law, the
rate of interest required to be paid thereunder shall be automatically reduced
to the maximum rate permitted under the governing law and such excess shall be
returned with reasonable promptness by the Holder to the Company.

            (e) It shall be the Company's responsibility to take all necessary
actions and to bear all such costs to issue the Common Stock as provided herein,
including the responsibility and cost for delivery of an opinion letter to the
transfer agent, if so required. The person in whose name the certificate of
Common Stock is to be registered shall be treated as a shareholder of record on
and after the conversion date. Upon surrender of any Debentures that are to be
converted in part, the Company shall issue to the Holder a new Debenture equal
to the unconverted amount, if so requested in writing by Holder.

            (f) Within three (3) business days after receipt of the
documentation referred to above in Section 3.2(a), the Company shall deliver a
certificate, in accordance with Section 3.2(c) for the number of shares of
Common Stock issuable upon the conversion. In the event the Company does not
make delivery of the Common Stock, as instructed by Holder, within three (3)
business days after the Conversion Date, then in such event the Company shall
pay to Holder three percent (3%) per day in cash, of the dollar value of the
Debentures being converted, compounded daily, per each day after the third (3rd)
business day following the Conversion Date that the Common Stock is not
delivered to the Purchaser, as liquidated damages.

                  The Company acknowledges that its failure to deliver the
Common Stock within three (3) business days after the Conversion Date will cause
the Holder to suffer damages in an amount that will be difficult to ascertain.
Accordingly, the parties agree that it is appropriate to include in this
Debenture a provision for liquidated damages. The parties acknowledge and agree
that the liquidated damages provision set forth in this section represents the
parties' good faith effort to quantify such damages and, as such, agree that the
form and amount of such liquidated damages are reasonable and will not
constitute a penalty. The payment of liquidated damages shall not relieve the
Company from its obligations to deliver the Common Stock pursuant to the terms
of this Debenture.


                                       4
<PAGE>

                To the extent that the failure of the Company to issue the
Common Stock pursuant to this Section 3.2(f) is due to the unavailability of
authorized but unissued shares of Common Stock, the provisions of this Section
3.2(f) shall not apply but instead the provisions of Section 3.2(m) shall apply.

                The Company shall make any payments incurred under this Section
3.2(f) in immediately available funds within three (3) business days from the
date the Common Stock is fully delivered. Nothing herein shall limit a Holder's
right to pursue actual damages or cancel the conversion for the Company's
failure to issue and deliver Common Stock to the Holder within three (3)
business days after the Conversion Date.

      The Company shall at all times reserve (or make alternative written
arrangements for reservation or contribution of shares) and have available all
Common Stock necessary to meet conversion of the Debentures by all Holders of
the entire amount of Debentures then outstanding. If, at any time Holder submits
a Notice of Conversion and the Company does not have sufficient authorized but
unissued shares of Common Stock (or alternative shares of Common Stock as may be
contributed by Stockholders) available to effect, in full, a conversion of the
Debentures (a "Conversion Default", the date of such default being referred to
herein as the "Conversion Default Date"), the Company shall issue to the Holder
all of the shares of Common Stock which are available, and the Notice of
Conversion as to any Debentures requested to be converted but not converted (the
"Unconverted Debentures"), may be deemed null and void upon written notice sent
by the Holder to the Company. The Company shall provide notice of such
Conversion Default ("Notice of Conversion Default") to all existing Holders of
outstanding Debentures, by facsimile, within three (3) business days of such
default (with the original delivered by overnight or two day courier), and the
Holder shall give notice to the Company by facsimile within five business days
of receipt of the Notice of Conversion Default (with the original delivered by
overnight or two day courier) of its election to either nullify or confirm the
Notice of Conversion.

      The Company agrees to pay to Holder of outstanding Debenture payments for
a Conversion Default ("Conversion Default Payments") in the amount of (N/365) x
(.24) x the initial issuance price of the outstanding and/or tendered but not
converted Debentures held by each Holder where N = the number of days from the
Conversion Default Date to the date (the "Authorization Date") that the Company
authorizes a sufficient number of shares of Common Stock to effect conversion of
all remaining Debentures. The Company shall send notice ("Authorization Notice")
to Holder of outstanding Debenture that additional shares of Common Stock have
been authorized; stating the Authorization Date and the amount of Holder's
accrued Conversion Default Payments. The accrued Conversion Default shall be
paid in cash or shall be convertible into Common Stock at the Conversion Rate,
upon written notice sent by the Holder to the Company, which Conversion Default
shall be payable as follows: (i) in the event Holder elects to take such payment
in cash, cash payments shall be made to such Holder of outstanding Debentures by
the fifth (5th) day of the following calendar month, or (ii) in the event Holder
elects to take such payment in stock, the Holder may convert such payment amount
into Common Stock at the conversion rate set forth in Section 3.2(c) at any time
after the fifth (5th) day of the calendar month following the month in which the
Authorization Notice was received, until the expiration of the mandatory three
(3) year conversion period.


                                       5
<PAGE>

      The Company acknowledges that its failure to maintain a sufficient number
of authorized but unissued shares of Common Stock to effect in full a conversion
of the Debenture will cause the Holder to suffer damages in an amount that will
be difficult to ascertain. Accordingly, the parties agree that it is appropriate
to include in this Agreement a provision for liquidated damages. The parties
acknowledge and agree that the liquidated damages provision set forth in this
section represents the parties' good faith effort to quantify such damages and,
as such, agree that the form and amount of such liquidated damages are
reasonable and will not constitute a penalty. The payment of liquidated damages
shall not relieve the Company from its obligations to deliver the Common Stock
pursuant to the terms of this Debenture. Nothing herein shall limit the Holder's
right to pursue actual damages for the Company's failure to maintain a
sufficient number of authorized shares of Common Stock.

      If, by the third (3rd) business day after the Conversion Date of any
portion of the Debenture to be converted (the "Delivery Date"), the transfer
agent fails for any reason to deliver the Common Stock upon conversion by the
Holder and after such Delivery Date the Holder purchases, in an open market
transaction or otherwise, shares of Common Stock (the "Covering Shares") solely
in order to make delivery in satisfaction of a sale of Common Stock by the
Holder (the "Sold Shares"), which delivery such Holder anticipated to make using
the Common Stock issuable upon conversion (a "Buy-In"), the Company shall pay to
the Holder, in addition to any other amounts due to Holder pursuant to this
Debenture, and not in lieu thereof, the Buy-In Adjustment Amount (as defined
below). The "Buy In Adjustment Amount" is the amount equal to the excess, if
any, of (x) the Holder's total purchase price (including brokerage commissions,
if any) for the Covering Shares over (y) the net proceeds (after brokerage
commissions, if any) received by the Holder from the sale of the Sold Shares.
The Company shall pay the Buy-In Adjustment Amount to the Holder in immediately
available funds within three (3) business days of written demand by the Holder.
By way of illustration and not in limitation of the foregoing, if the Holder
purchases shares of Common Stock having a total purchase price (including
brokerage commissions) of $11,000 to cover a Buy-In with respect to shares of
Common Stock it sold for net proceeds of $10,000, the Buy-In Adjustment Amount
which the Company will be required to pay to the Holder will be $1,000.

            (g) Prospectus and Other Documents. The Company shall furnish to
Holder such number of prospectuses and other documents incidental to the
registration of the shares of Common Stock underlying the Debentures, including
any amendment of or supplements thereto. Any filings submitted via EDGAR will
constitute fulfillment.

            (h) Limitation on Issuance of Shares. If the Company's Common Stock
becomes listed on the Nasdaq SmallCap Market after the issuance of the
Debenture, the Company may be limited in the number of shares of Common Stock it
may issue by virtue of (X) the number of authorized shares or (Y) the applicable
rules and regulations of the principal securities market on which the Common
Stock is listed or traded, including, but not necessarily limited to, NASDAQ
Rule 4310(c)(25)(H)(i) or Rule 4460(i)(1), as may be applicable (collectively,
the "Cap Regulations"). Without limiting the other provisions thereof, (i) the
Company will take all steps reasonably necessary to be in a position to issue
shares of Common Stock on conversion of the Debentures without violating the Cap
Regulations and (ii) if, despite taking such steps, the Company still cannot
issue such shares of Common Stock without violating the Cap Regulations, the
holder of a Debenture which cannot be converted as result of the Cap Regulations
(each such Debenture, an "Unconverted Debenture") shall have the right to elect
either of the following remedies:


                                       6
<PAGE>

            (x) if permitted by the Cap Regulations, require the Company to
      issue shares of Common Stock in accordance with such holder's Notice of
      Conversion at a conversion purchase price equal to the average of the
      closing bid price per share of Common Stock for any five (5) consecutive
      Trading Days (subject to certain equitable adjustments for certain events
      occurring during such period) during the sixty (60) Trading Days
      immediately preceding the Conversion Date; or

            (y) require the Company to redeem each Unconverted Debenture for an
      amount (the "Redemption Amount"), payable in cash, equal to the sum of (i)
      one hundred thirty-three percent (133%) of the principal of an Unconverted
      Debenture, plus (ii) any accrued but unpaid interest thereon through and
      including the date (the "Redemption Date") on which the Redemption Amount
      is paid to the holder.

      A holder of an Unconverted Debenture may elect one of the above remedies
with respect to a portion of such Unconverted Debenture and the other remedy
with respect to other portions of the Unconverted Debenture. The Debenture shall
contain provisions substantially consistent with the above terms, with such
additional provisions as may be consented to by the Holder. The provisions of
this section are not intended to limit the scope of the provisions otherwise
included in the Debenture.

            (i) Limitation on Amount of Conversion and Ownership.
Notwithstanding anything to the contrary in this Debenture, in no event shall
the Holder be entitled to convert that amount of Debenture, and in no event
shall the Company permit that amount of conversion, into that number of shares,
which when added to the sum of the number of shares of Common Stock beneficially
owned, (as such term is defined under Section 13(d) and Rule 13d-3 of the
Securities Exchange Act of 1934, as may be amended, (the "1934 Act")), by the
Holder, would exceed 4.99% of the number of shares of Common Stock outstanding
on the Conversion Date, as determined in accordance with Rule 13d-1(j) of the
1934 Act. In the event that the number of shares of Common Stock outstanding as
determined in accordance with Section 13(d) of the 1934 Act is different on any
Conversion Date than it was on the Closing Date, then the number of shares of
Common Stock outstanding on such Conversion Date shall govern for purposes of
determining whether the Holder would be acquiring beneficial ownership of more
than 4.99% of the number of shares of Common Stock outstanding on such
Conversion Date.


                                       7
<PAGE>

            (j) Legend. The Holder acknowledges that each certificate
representing the Debentures, and the Common Stock unless registered pursuant to
the Registration Rights Agreement, shall be stamped or otherwise imprinted with
a legend substantially in the following form:

THE SECURITIES EVIDENCED BY THIS CERTIFICATE MAY NOT BE OFFERED OR SOLD,
TRANSFERRED, PLEDGED, HYPOTHECATED OR OTHERWISE DISPOSED OF EXCEPT (i) PURSUANT
TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933, AS
AMENDED, (ii) TO THE EXTENT APPLICABLE, RULE 144 UNDER THE ACT (OR ANY SIMILAR
RULE UNDER SUCH ACT RELATING TO THE DISPOSITION OF SECURITIES), OR (iii) IF AN
EXEMPTION FROM REGISTRATION UNDER SUCH ACT IS AVAILABLE.

            (k) Prior to conversion of the Debenture, if at any time the
conversion of all the Debentures and exercise of all the Warrants outstanding
would result in an insufficient number of authorized shares of Common Stock
being available to cover all the conversions, then in such event, the Company
will move to call and hold a shareholder's meeting or have shareholder action
with written consent of the proper number of shareholders within thirty (30)
days of such event, or such greater period of time if statutorily required or
reasonably necessary as regards standard brokerage house and/or SEC requirements
and/or procedures, for the purpose of authorizing additional shares of Common
Stock to facilitate the conversions. In such an event management of the Company
shall recommend to all shareholders to vote their shares in favor of increasing
the authorized number of shares of Common Stock. Management of the Company shall
vote all of its shares of Common Stock in favor of increasing the number of
shares of authorized Common Stock. The Company represents and warrants that
under no circumstances will it deny or prevent Holder's right to convert the
Debentures as permitted under the terms of this Subscription Agreement or the
Registration Rights Agreement. Nothing in this Section shall limit the
obligation of the Company to make the payments set forth in Section 3.2(g). The
investor, at his option, may request the company to authorize and issue
additional shares if the investor feels it is necessary for conversions in the
future. In the event the Company's shareholder's meeting does not result in the
necessary authorization, the Company shall redeem the outstanding Debentures for
an amount equal to (x) the sum of the principal of the outstanding Debentures
plus accrued interest thereon multiplied by (y) 133%.

      Section 3.3 Fractional Shares. The Company shall not issue fractional
shares of Common Stock, or scrip representing fractions of such shares, upon the
conversion of this Debenture. Instead, the Company shall round up or down, as
the case may be, to the nearest whole share.

      Section 3.4 Taxes on Conversion. The Company shall pay any documentary,
stamp or similar issue or transfer tax due on the issue of shares of Common
Stock upon the conversion of this Debenture. However, the Holder shall pay any
such tax which is due because the shares are issued in a name other than its
name.


                                       8
<PAGE>

      Section 3.5 Company to Reserve Stock. The Company shall reserve the number
of shares of Common Stock required pursuant to and upon the terms set forth in
the Subscription Agreement to permit the conversion of this Debenture. All
shares of Common Stock which may be issued upon the conversion hereof shall upon
issuance be validly issued, fully paid and nonassessable and free from all
taxes, liens and charges with respect to the issuance thereof.

      Section 3.6 Restrictions on Sale. This Debenture has not been registered
under the Securities Act of 1933, as amended, (the "Act") and is being issued
under Section 4(2) of the Act and Rule 506 of Regulation D promulgated under the
Act. This Debenture and the Common Stock issuable upon the conversion thereof
may only be sold pursuant to registration under or an exemption from the Act.

Article 4         Mergers

      The Company shall not consolidate or merge into, or transfer all or
substantially all of its assets to, any person, unless such person assumes in
writing the obligations of the Company under this Debenture and immediately
after such transaction no Event of Default exists. Any reference herein to the
Company shall refer to such surviving or transferee corporation and the
obligations of the Company shall terminate upon such written assumption.

Article 5     Security

      This Debenture is secured by a Security Agreement (the "Security
Agreement") of even date herewith between the Company and the Holder.

Article 6         Defaults and Remedies

      Section 6.1 Events of Default. An "Event of Default" occurs if (a) the
Company does not make the Payment of the principal of this Debenture by
conversion into Common Stock within five (5) business days of the Maturity Date,
upon redemption or otherwise, (b) the Company does not make a payment, other
than a payment of principal, for a period of three (3) business days thereafter,
(c) any of the Company's representations or warranties contained in the
Subscription Agreement or this Debenture were false when made or the Company
fails to comply with any of its other agreements in the Transaction Documents
(as defined in Article 16 below) and such failure continues for a period of five
(5) business days, (d) the Company pursuant to or within the meaning of any
Bankruptcy Law (as hereinafter defined): (i) commences a voluntary case; (ii)
consents to the entry of an order for relief against it in an involuntary case;
(iii) consents to the appointment of a Custodian (as hereinafter defined) of it
or for all or substantially all of its property or (iv) makes a general
assignment for the benefit of its creditors or (v) a court of competent
jurisdiction enters an order or decree under any Bankruptcy Law that: (A) is for
relief against the Company in an involuntary case; (B) appoints a Custodian of
the Company or for all or substantially all of its property or (C) orders the
liquidation of the Company, and the order or decree remains unstayed and in
effect for sixty (60) calendar days, (e) the Company's Common Stock is suspended
or no longer listed on any recognized exchange including electronic
over-the-counter bulletin board for in excess of five (5) consecutive Trading
Days (e) the Company violates any terms and conditions of the Registration
Rights Agreement (f) the Registration Statement underlying the Debenture is not
declared effective by the SEC within twelve (12) months of the Issuance Date.


                                       9
<PAGE>

      As used in this Section 6.1, the term "Bankruptcy Law" means Title 11 of
the United States Code or any similar federal or state law for the relief of
debtors. The term "Custodian" means any receiver, trustee, assignee, liquidator
or similar official under any Bankruptcy Law. A default under clause (c) or (e)
above is not an Event of Default until the holders of at least one hundred
percent (100%) of the aggregate principal amount of the Debentures outstanding
notify the Company of such default and the Company does not cure it within five
(5) business days after the receipt of such notice, unless the Company commences
to cure such default within such period, which must specify the default, demand
that it be remedied and state that it is a "Notice of Default". Prior to the
expiration of the time for curing a default as set forth in the preceding
sentence, the holders of a majority in aggregate principal amount of the
Debentures at the time outstanding (exclusive of Debentures then owned by the
Company or any subsidiary or affiliate) may, on behalf of the holders of all of
the Debentures, waive any past Event of Default hereunder (or any past event
which, with the lapse of time or notice and lapse of time designated in
subsection (a), would constitute an Event of Default hereunder) and its
consequences, except a default in the payment of the principal of or interest on
any of the Debentures. In the case of any such waiver, such default or Event of
Default shall be deemed to have been cured for every purpose of this Debenture
and the Company and the holders of the Debentures shall be restored to their
former positions and rights hereunder, respectively; but no such waiver shall
extend to any subsequent or other default or impair any right consequent
thereon.

      In the Event of Default and provided the Debentures have not been paid in
full, the Holder may elect to secure a portion of the Company's assets not to
exceed 200% of the Face Amount of the Note, in Pledged Collateral (as defined in
the Security Agreement). The Holder may also elect to garnishee Revenue from the
Company in an amount that will repay the Holder on the schedules outlined in
this Agreement.

      In the Event of Default, as outlined in this Agreement, the Holder can
exercise its right to increase the Face Amount of the Debenture by ten percent
(10%) as an initial penalty and for each Event of Default under this Agreement.
In addition, the Holder may elect to increase the Face Amount by two and
one-half percent (2.5%) per month (pro-rata for partial periods) paid as a
penalty for liquated damages ("Liquidated Damages"). The Liquated Damages will
be compounded daily. It is the intention and acknowledgement of both parties
that the Liquidated Damages not be deemed as interest.

      In the event of Default, specifically to Section 6.1 (f), the Holder may
elect to switch the Conversion Price of the Debenture as outlined in Section 3.2
(c) above ("Default Conversion Price"). The Default Conversion Price shall be
equal to the lesser of a) the Fixed Conversion Price or b) seventy percent (70%)
of the lowest closing bid price of the Common Stock during the fifteen (15)
trading days prior to conversion. Upon written notice being sent to the Company
by the Holder of Default under Section 6.1 (f), and the Holder's election to
exercise the remedy to switch the conversion price to the Default Conversion
Price, the Company shall immediately withdraw the Registration Statement.
Further, the Company agrees that the date of consideration for the Debenture
shall remain the Issuance Date stated herein. The Company shall provide an
opinion letter from counsel within two (2) business days of written request by
the Holder stating that the date of consideration for the Debenture is the
Issuance Date and submission of proper Rule 144 support documentation consisting
of Form 144, a broker's representation letter and a seller's representation
letter. In the event the Company does not deliver the opinion letter within two
business days, the Default Conversion Price shall immediately decrease by two
percent (2%) for each business day an opinion letter fails to be delivered. In
the event that counsel to the Company fails or refuses to render an opinion as
required to issue the Shares in accordance with this paragraph (either with or
without restrictive legends, as applicable), then the Company irrevocably and
expressly authorizes counsel to the Investor to render such opinion and shall
authorize the Transfer Agent shall accept and be entitled to rely on such
opinion for the purposes of issuing the Shares (which is attached as Exhibit E
to the Subscription Agreement between the Company and the Holder of even date).
Any costs incurred by Holder for such opinion letter shall be added to the Face
Amount of the Debenture.


                                       10
<PAGE>

      Section 6.2 Acceleration. If an Event of Default occurs and is continuing,
the Holder hereof by notice to the Company may declare the remaining principal
amount of this Debenture, together with all accrued interest and any liquidated
damages, to be due and payable. Upon such declaration, the remaining principal
amount shall be due and payable immediately.

      Section 6.3 Seniority. No indebtedness of the Company is senior to this
Debenture in right of payment, whether with respect to interest, damages or upon
liquidation or dissolution or otherwise.

Article 7         Registered Debentures

      Section 7.1 Record Ownership. The Company, or its attorney, shall maintain
a register of the holders of the Debentures (the "Register") showing their names
and addresses and the serial numbers and principal amounts of Debentures issued
to them. The Register may be maintained in electronic, magnetic or other
computerized form. The Company may treat the person named as the Holder of this
Debenture in the Register as the sole owner of this Debenture. The Holder of
this Debenture is the person exclusively entitled to receive payments of
interest on this Debenture, receive notifications with respect to this
Debenture, convert it into Common Stock and otherwise exercise all of the rights
and powers as the absolute owner hereof.

             Worn or Lost Debentures. If this Debenture becomes worn, defaced or
mutilated but is still substantially intact and recognizable, the Company or its
agent may issue a new Debenture in lieu hereof upon its surrender. Where the
Holder of this Debenture claims that the Debenture has been lost, destroyed or
wrongfully taken, the Company shall issue a new Debenture in place of the
Debenture if the Holder so requests by written notice to the Company actually
received by the Company before it is notified that the Debenture has been
acquired by a bona fide purchaser and the Holder has delivered to the Company an
indemnity bond in such amount and issued by such surety as the Company deems
satisfactory together with an affidavit of the Holder setting forth the facts
concerning such loss, destruction or wrongful taking and such other information
in such form with such proof or verification as the Company may request.


                                       11
<PAGE>

Article 8         Notice.

      Any notices, consents, waivers or other communications required or
permitted to be given under the terms of this Debenture must be in writing and
will be deemed to have been delivered (i) upon receipt, when delivered
personally; (ii) upon receipt, when sent by facsimile (provided a confirmation
of transmission is mechanically or electronically generated and kept on file by
the sending party); or (iii) one (1) day after deposit with a nationally
recognized overnight delivery service, in each case properly addressed to the
party to receive the same. The addresses and facsimile numbers for such
communications shall be:

If to the Company:

Mark Clancy
Hybrid Fuel Systems
12409 Telecom Drive
Tampa, FL 33637
Telephone: 813-979-9222
Facsimile:  813-979-9224

Darrin M. Ocasio, Esq.
Sichenzia Ross Friedman Ference LLP
1065 Avenue of the Americas, 21st flr.
New York, NY 10018

Telephone: 212-930-9700
Facsimile:  212-930-9725

If to the Investor:

      At the address listed in the Questionnaire.

      Each party shall provide five (5) business days prior notice to the other
party of any change in address, phone number or facsimile number.

Article 9         Time

      Where this Debenture authorizes or requires the payment of money or the
performance of a condition or obligation on a Saturday or Sunday or a public
holiday, or authorizes or requires the payment of money or the performance of a
condition or obligation within, before or after a period of time computed from a
certain date, and such period of time ends on a Saturday or a Sunday or a public
holiday, such payment may be made or condition or obligation performed on the
next succeeding business day, and if the period ends at a specified hour, such
payment may be made or condition performed, at or before the same hour of such
next succeeding business day, with the same force and effect as if made or
performed in accordance with the terms of this Debenture. A "business day" shall
mean a day on which the banks in New York are not required or allowed to be
closed.


                                       12
<PAGE>

Article 10        No Assignment

      This Debenture shall not be assignable.

Article 11        Rules of Construction.

      In this Debenture, unless the context otherwise requires, words in the
singular number include the plural, and in the plural include the singular, and
words of the masculine gender include the feminine and the neuter, and when the
sense so indicates, words of the neuter gender may refer to any gender. The
numbers and titles of sections contained in the Debenture are inserted for
convenience of reference only, and they neither form a part of this Debenture
nor are they to be used in the construction or interpretation hereof. Wherever,
in this Debenture, a determination of the Company is required or allowed, such
determination shall be made by a majority of the Board of Directors of the
Company and if it is made in good faith, it shall be conclusive and binding upon
the Company and the Holder of this Debenture.


Article 12        Governing Law

      The validity, terms, performance and enforcement of this Debenture shall
be governed and construed by the provisions hereof and in accordance with the
laws of the Commonwealth of Massachusetts applicable to agreements that are
negotiated, executed, delivered and performed solely in the Commonwealth of
Massachusetts.

Article 13        Litigation

DISPUTES SUBJECT TO ARBITRATION GOVERNED BY MASSACHUSETTS LAW

      All disputes arising under this agreement shall be governed by and
interpreted in accordance with the laws of the Commonwealth of Massachusetts,
without regard to principles of conflict of laws. The parties to this agreement
will submit all disputes arising under this agreement to arbitration in Boston,
Massachusetts before a single arbitrator of the American Arbitration Association
("AAA"). The arbitrator shall be selected by application of the rules of the
AAA, or by mutual agreement of the parties, except that such arbitrator shall be
an attorney admitted to practice law in the Commonwealth of Massachusetts. No
party to this agreement will challenge the jurisdiction or venue provisions as
provided in this section.


                                       13
<PAGE>

Article 14  Redemption

      The Holder shall have the right to be redeemed from the Debenture, in
whole or in part, at a price equal to one hundred and twenty-five percent (125%)
of the outstanding principal amount of the Debenture, including accrued interest
(and penalties if applicable). Any Payments, as defined in Article 2 above,
shall apply to the Redemption Amount. The Holder also holds the right to use the
existing equity line to redeem the Debenture.

Article 15  Investor Warrants

      As an additional inducement to Holder, the Company shall issue a warrant
to purchase eighty-five thousand dollars ($85,000) worth of shares of its common
stock exercisable at the Fixed Conversion Price outlined in the Warrant
Agreement, attached hereto and incorporated by reference, to Holder.

Article 16  Transaction Documents

      The Company agrees that contemporaneously with the execution and delivery
of this Debenture, the parties hereto are executing and delivering a Debenture
Registration Rights Agreement, Subscription Agreement, Warrant Agreement,
Security Agreement and the Irrevocable Transfer Agent Agreement between the
Company and Dutchess Capital Management, LLC (collectively, the "Transaction
Documents") pursuant to which the Company has agreed to provide certain rights
and obligations as defined in the documents.

Article 17  Waiver

      The Holder's delay or failure at any time or times hereafter to require
strict performance by Company of any undertakings, agreements or covenants shall
not waiver, affect, or diminish any right of the Holder under this Agreement to
demand strict compliance and performance herewith. Any waiver by the Holder of
any Event of Default shall not waive or affect any other Event of Default,
whether such Event of Default is prior or subsequent thereto and whether of the
same or a different type. None of the undertakings, agreements and covenants of
the Company contained in this Agreement, and no Event of Default, shall be
deemed to have been waived by the Holder, nor may this Agreement be amended,
changed or modified, unless such waiver, amendment, change or modification is
evidenced by an instrument in writing specifying such waiver, amendment, change
or modification and signed by the Holder.

Article 18  Waiver of Jury Trial.

AS A MATERIAL INDUCEMENT FOR EACH PARTY HERETO TO ENTER INTO THIS AGREEMENT, THE
PARTIES HERETO HEREBY WAIVE ANY RIGHT TO TRIAL BY JURY IN ANY LEGAL PROCEEDING
RELATED IN ANY WAY TO THIS AGREEMENT AND/OR ANY AND ALL OF THE OTHER DOCUMENTS
ASSOCIATED WITH THIS TRANSACTION.

                                          *.*.*


                                       14
<PAGE>

      IN WITNESS WHEREOF, the Company has duly executed this Debenture as of the
date first written above and duly authorized to sign on behalf of:

                                    HYBRID FUEL SYSTEMS, INC.


                                    By: /s/ Mark Clancy _
                                        ----------------------------------------
                                    Name: Mark Clancy
                                    Title: Chief Executive Officer


                                    By: /s/ John Stanton
                                        ----------------------------------------
                                    Name: John Stanton
                                    Title: Chairman of the Board


                                    DUTCHESS PRIVATE EQUITIES FUND, II, L.P.
                                    BY ITS GENERAL PARTNER DUTCHESS
                                    CAPITAL MANAGEMENT, LLC


                                    By: /s/ Douglas H. Leighton
                                        ----------------------------------------
                                    Name: Douglas H. Leighton
                                    Title: A Managing Member


                                       15
<PAGE>

                                    Exhibit A

                              NOTICE OF CONVERSION

          (To be Executed by the Registered Owner in order to Convert Debenture)
Hybrid Fuel Systems, Inc.

      The undersigned hereby irrevocably elects, as of ________________, to
convert $________________ of its convertible debenture (the "Debenture") into
Common Stock of Hybrid Fuel Systems, Inc. (the "Company") according to the
conditions set forth in the Debenture issued by the Company.

Date of Conversion
                  --------------------------------------------------------------

Applicable Conversion Price
                           -----------------------------------------------------

Number of Debentures Issuable upon this Conversion
                                                  ------------------------------

Name(Print)           Dutchess Private Equities Fund, II, LP
           ---------------------------------------------------------------------

Address              50 Commonwealth Ave, Boston, MA 02116
       -------------------------------------------------------------------------


Phone     617-301-4700              Fax        617-249-0947
     ------------------------------    -----------------------------------------





                   By:
                      ---------------------------------------
                      Douglas Leighton


                                       16
<PAGE>

                           EXHIBIT B PAYMENT SCHEDULE

<TABLE>
<CAPTION>
Convertible           Interest           Redemption                                                                  PMT
Amount                Rate                                                                                           $
$ 340,000.00                 12%                 125%                                                                40,498.44

                                         Amount with
                                         Accrued                                                                     Applied
                                         Interest                               Applied to          Applied to       to
                      Amount Due         for Period           Payment           Principal           Interest         Redemption
---------          ----------------   ----------------   ----------------   ----------------    ----------------   ----------------
<S>                <C>                <C>                <C>                <C>                 <C>                <C>
 8/1/2005          $     340,000.00   $     343,369.46   $       3,369.46   $          (0.00)   $       3,369.46   $          (0.00)
 9/1/2005          $     340,000.00   $     343,369.46   $       3,369.46   $          (0.00)   $       3,369.46   $          (0.00)
10/1/2005          $     340,000.00   $     343,369.46   $       3,369.46   $          (0.00)   $       3,369.46   $          (0.00)
11/1/2005          $     340,000.00   $     343,369.46   $      40,498.44   $      29,703.18    $       3,369.46   $      37,128.98
12/1/2005          $     310,296.82   $     313,371.91   $      40,498.44   $      29,938.67    $       3,075.10   $      37,423.34
 1/1/2006          $     280,358.15   $     283,136.54   $      40,498.44   $      30,176.03    $       2,778.40   $      37,720.04
 2/1/2006          $     250,182.11   $     252,661.46   $      40,498.44   $      30,415.27    $       2,479.35   $      38,019.09
 3/1/2006          $     219,766.84   $     221,944.77   $      40,498.44   $      30,656.41    $       2,177.93   $      38,320.51
 4/1/2006          $     189,110.44   $     190,984.55   $      40,498.44   $      30,899.46    $       1,874.12   $      38,624.32
 5/1/2006          $     158,210.98   $     159,778.88   $      40,498.44   $      31,144.43    $       1,567.90   $      38,930.54
 6/1/2006          $     127,066.55   $     128,325.80   $      40,498.44   $      31,391.35    $       1,259.25   $      39,239.19
 7/1/2006          $      95,675.20   $      96,623.36   $      40,498.44   $      31,640.22    $         948.16   $      39,550.28
 8/1/2006          $      64,034.98   $      64,669.58   $      40,498.44   $      31,891.07    $         634.60   $      39,863.84
 9/1/2006          $      32,143.91   $      32,462.46   $      40,498.44   $      32,143.91    $         318.55   $      40,179.89
10/1/2006          $           0.00   $           0.00   $      40,498.44   $      32,398.75    $           0.00   $      40,498.44
</TABLE>



                                       17