CONTRIBUTION, CONVEYANCE AND ASSUMPTION AGREEMENT

This  Contribution,  Conveyance  and  Assumption Agreement (this "Agreement") is
entered  into  as of September 16, 2004, by and among Penn Octane Corporation, a
Delaware  corporation  ("POCC"),  Rio Vista GP LLC, a Delaware limited liability
company  (the  "GP"),  Rio  Vista  Energy  Partners  L.P.,  a  Delaware  limited
partnership  (the  "MLP"),  Rio  Vista  Operating  GP  LLC,  a  Delaware limited
liability  company  (the  "Operating  GP"),  and Rio Vista Operating Partnership
L.P.,  a  Delaware  limited  partnership  (the  "Operating  Partnership").

                                    RECITALS

     WHEREAS,  prior  to  the date hereof, POCC formed the GP, as a wholly-owned
direct  subsidiary,  and  purchased  for  $1,000.00 all of the limited liability
company  interests  in  the  GP;

     WHEREAS,  the  GP  and  POCC  formed  the  MLP, with the GP purchasing a 2%
general partner interest for $20 and POCC purchasing common units representing a
98%  limited  partner  interest  for  $980.00;

     WHEREAS,  the  MLP formed the Operating GP and purchased all of the limited
liability  company  interests  in  the  Operating  GP  for  $1,000.00;

     WHEREAS,  POCC  and the Operating GP formed the Operating Partnership, with
the  Operating GP purchasing a 0.10% general partner interest for $1.00 and POCC
purchasing  a  99.9%  limited  partner  interest  for  $999.00;

     WHEREAS,  each  of  the  following transactions shall occur as of 4:58 P.M.
Eastern  Time  on  September  30,  2004  (the  "Contribution  Effective  Time"):

     1.  POCC  will  contribute all of its ownership interest in the outstanding
capital  stock  of  its  subsidiaries  (the "Subsidiary Interests") set forth on
Exhibit  A (the "Subsidiaries") hereto to the Operating Partnership as a capital
- ----------
contribution;

     2.  POCC  will contribute to the Operating Partnership the assets set forth
in the Conveyance Agreement described in Section 1.2 below (the "LPG Assets") as
an  additional  capital  contribution;  and

     3.  The  GP  will  convey $1,000 to the MLP in exchange for the issuance of
incentive  distribution  rights  to  the  GP;

     WHEREAS,  each  of  the  following transactions shall occur as of 4:59 P.M.
Eastern  Time  on  September  30,  2004  (the  "Closing  Day  Effective  Time"):

     1.  POCC  will  contribute  all  of  its  limited  partner  interest in the
Operating  Partnership  to  the  MLP  as  an  additional  capital  contribution.

     NOW,  THEREFORE,  in  consideration  of  their  mutual  undertakings  and
agreements  hereunder,  the  parties  to  this  Agreement undertake and agree as
follows:

                                    ARTICLE I

         CONVERSIONS, CONTRIBUTIONS AND DISTRIBUTIONS OF VARIOUS ASSETS

     SECTION  1.1     CONTRIBUTION  OF  THE  SUBSIDIARY INTERESTS BY POCC TO THE
OPERATING  PARTNERSHIP.  At the Contribution Effective Time, POCC hereby grants,
contributes,  transfers,  assigns  and conveys to the Operating Partnership, its
successors  and  assigns, all right, title and interest in and to the Subsidiary
Interests as a capital contribution and the Operating Partnership hereby accepts
the  Subsidiary  Interests.



     SECTION  1.2  CONTRIBUTION  OF  LPG  ASSETS  BY  POCC  TO  THE  OPERATING
PARTNERSHIP.  At  the  Contribution  Effective  Time,  POCC  hereby  grants,
contributes,  transfers,  assigns  and conveys to the Operating Partnership, its
successors  and  assigns, all right, title and interest in and to the LPG Assets
as  a capital contribution, and the Operating Partnership hereby accepts the LPG
Assets.  In  order  to  give  full  effect to the foregoing grant, contribution,
transfer,  assignment  and  conveyance,  POCC,  as  grantor,  and  the Operating
Partnership,  as  grantee,  shall  execute  a  Conveyance  Agreement in the form
attached  hereto  as  Exhibit B together with such other special warranty deeds,
                      ---------
conveyances  or  other  documents  required  to  transfer  the LPG Assets in the
jurisdictions  in  which  they  are  located.

     SECTION  1.3  CONTRIBUTION OF OPERATING PARTNERSHIP INTEREST BY POCC TO THE
MLP.  At  the  Closing  Day  Effective  Time,  POCC  hereby grants, contributes,
transfers,  assigns  and  conveys  to  the  MLP, its successors and assigns, all
right,  title  and interest of POCC in and to the 99.9% limited partner interest
in  the  Operating  Partnership as an additional capital contribution to the MLP
and  the  MLP  hereby  accepts  such  limited  partner interest as an additional
capital  contribution  to  the  MLP.

     SECTION  1.4 CONVEYANCE BY THE GP TO THE MLP. At the Contribution Effective
Time,  the  GP  hereby  conveys  to the MLP $1,000.00 in exchange for all of the
incentive  distribution rights under the First Amended and Restated Agreement of
Limited  Partnership  of  the  MLP.

                                   ARTICLE II

                 RECORDATION OF EVIDENCE OF OWNERSHIP OF ASSETS

     SECTION  2.1.  In  connection  with the conveyances that are referred to in
Article  I  to  this  Agreement,  the parties to this Agreement acknowledge that
certain  jurisdictions  in  which  the  assets of the applicable parties to such
conveyances  are  located may require that documents be recorded by such parties
resulting  from  such conveyances in order to evidence title to the assets owned
by  such  parties.  All such documents shall evidence such new ownership and are
not  intended  to  modify, and shall not modify, any of the terms, covenants and
conditions  herein  set  forth.

                                   ARTICLE III

                        ASSUMPTION OF CERTAIN LIABILITIES

     SECTION  3.1     ASSUMPTION OF LIABILITIES AND OBLIGATIONS BY THE OPERATING
PARTNERSHIP AND THE MLP.  In connection with the contributions of the LPG Assets
and  the  Subsidiary  Interests  to  the  Operating  Partnership,  the Operating
Partnership  hereby  assumes  and  agrees  to  duly  and timely pay, perform and
discharge  all  obligations  and  liabilities  associated  with  the Contributed
Assets,  that  arise  from and after the Closing Day Effective Time, to the full
extent that either of the Subsidiaries or POCC would have been obligated to pay,
perform  and  discharge  such obligations and liabilities in the future, were it
not  for  the  execution and delivery of this Agreement; provided, however, that
said assumption and agreement to duly and timely pay, perform and discharge such
obligations  and  liabilities shall not increase the obligation of the Operating
Partnership with respect to such obligations and liabilities beyond that of POCC
as  to  the  LPG  Assets,  or  the Subsidiaries as to the assets acquired by the
Operating  Partnership  in  such  interest  conveyed  by  any  of  POCC  or  the
Subsidiaries.  For  purposes  of  this  Agreement, the term "Contributed Assets"
shall  mean,  collectively,  the  LPG  Assets  and  the  Subsidiary  Interests.


                                        2

                                   ARTICLE IV

                                  TITLE MATTERS

     SECTION  4.1  DISCLAIMER  OF  WARRANTIES;  SUBROGATION.

     (a)  (i)  NOTWITHSTANDING  ANYTHING  TO  THE  CONTRARY  CONTAINED  IN  THIS
          AGREEMENT, THE MLP AND THE OPERATING PARTNERSHIP ACKNOWLEDGE AND AGREE
          THAT  POCC  AND  THE  SUBSIDIARIES  HAVE  NOT  MADE,  DO NOT MAKE, AND
          SPECIFICALLY  NEGATE  AND  DISCLAIM,  ANY REPRESENTATIONS, WARRANTIES,
          PROMISES, COVENANTS, AGREEMENTS OR GUARANTIES OF ANY KIND OR CHARACTER
          WHATSOEVER,  WHETHER  EXPRESS,  IMPLIED OR STATUTORY, ORAL OR WRITTEN,
          PAST OR PRESENT (ALL OF WHICH ARE EXPRESSLY DISCLAIMED BY POCC AND THE
          SUBSIDIARIES)  REGARDING  (1)  THE  TITLE,  VALUE,  NATURE, QUALITY OR
          CONDITION OF THE CONTRIBUTED ASSETS, (2) THE INCOME TO BE DERIVED FROM
          THE  CONTRIBUTED ASSETS, (3) THE SUITABILITY OF THE CONTRIBUTED ASSETS
          FOR ANY AND ALL ACTIVITIES AND USES WHICH THE MLP MAY CONDUCT THEREON,
          (4)  THE  COMPLIANCE  OF  OR  BY  THE  CONTRIBUTED  ASSETS,  OR  THEIR
          OPERATIONS  WITH  ANY  LAWS  (INCLUDING WITHOUT LIMITATION ANY ZONING,
          ENVIRONMENTAL  PROTECTION,  POLLUTION  OR  LAND  USE  LAWS,  RULES,
          REGULATIONS,  ORDERS  OR  REQUIREMENTS),  OR  (5)  THE  HABITABILITY,
          MERCHANTABILITY,  MARKETABILITY,  PROFITABILITY  OR  FITNESS  FOR  A
          PARTICULAR  PURPOSE  OF  THE  CONTRIBUTED  ASSETS.

     (ii) THE  MLP AND THE OPERATING PARTNERSHIP ACKNOWLEDGE AND AGREE THAT THEY
          HAVE  HAD  THE OPPORTUNITY TO INSPECT THE CONTRIBUTED ASSETS, AND THAT
          THEY  ARE RELYING SOLELY ON THEIR OWN INVESTIGATION OF THE CONTRIBUTED
          ASSETS,  AND NOT ON ANY INFORMATION PROVIDED OR TO BE PROVIDED BY POCC
          AND  THE SUBSIDIARIES, AND POCC AND THE SUBSIDIARIES ARE NOT LIABLE OR
          BOUND  IN  ANY  MANNER  BY  ANY  VERBAL  OR  WRITTEN  STATEMENTS,
          REPRESENTATIONS  OR  INFORMATION PERTAINING TO THE CONTRIBUTED ASSETS,
          FURNISHED  BY  ANY  AGENT,  EMPLOYEE,  SERVANT  OR  THIRD  PARTY.

     (iii) THE MLP AND THE OPERATING PARTNERSHIP ACKNOWLEDGE THAT TO THE MAXIMUM
          EXTENT  PERMITTED  BY LAW, THE CONTRIBUTION OF THE CONTRIBUTED ASSETS,
          AS  PROVIDED  FOR  HEREIN IS MADE ON AN "AS IS", "WHERE IS" BASIS WITH
          ALL  FAULTS AND THE CONTRIBUTED ASSETS, ARE CONTRIBUTED OR DISTRIBUTED
          AND  CONVEYED  BY  POCC AND THE SUBSIDIARIES SUBJECT TO THE FOREGOING.
          THIS  PARAGRAPH  SHALL  SURVIVE  SUCH CONTRIBUTION OR DISTRIBUTION AND
          CONVEYANCE  OR  THE  TERMINATION  OF  THIS  AGREEMENT.

     (iv) THE  PROVISIONS  OF THIS SECTION 4.1 HAVE BEEN NEGOTIATED BY POCC, THE
          SUBSIDIARIES,  THE  MLP  AND  THE  OPERATING  PARTNERSHIP  AFTER  DUE
          CONSIDERATION AND ARE INTENDED TO BE A COMPLETE EXCLUSION AND NEGATION
          OF  ANY  REPRESENTATIONS  OR  WARRANTIES OF POCC AND THE SUBSIDIARIES,
          WHETHER EXPRESS, IMPLIED OR STATUTORY, WITH RESPECT TO THE CONTRIBUTED
          ASSETS, THAT MAY ARISE PURSUANT TO ANY LAW NOW OR HEREAFTER IN EFFECT,
          OR  OTHERWISE.

     (b)  The contributions of the Contributed Assets, made under this Agreement
          are  made  with  full  rights  of  substitution and subrogation of the
          Operating  Partnership, and all persons claiming by, through and under
          the  Operating  Partnership,  to  the extent assignable, in and to all
          covenants  and warranties by the predecessors-in-title of POCC and the
          Subsidiaries,  and  with full subrogation of all rights accruing under
          applicable statutes of limitation and all rights of action of warranty


                                        3

          against  all  former  owners  of  the  Contributed  Assets.

     (c)  POCC, the Subsidiaries, the MLP, the GP, the Operating Partnership and
          Operating  GP agree that the disclaimers contained in this Section 4.1
          are "conspicuous" disclaimers. Any covenants implied by statute or law
          by  the  use  of  the  words  "grant,"  "convey,"  "bargain,"  "sell,"
          "assign,"  "transfer,"  "deliver," or "set over" or any of them or any
          other  words  used in this Agreement or any exhibits hereto are hereby
          expressly  disclaimed,  waived  or  negated.

                                    ARTICLE V

                               FURTHER ASSURANCES

     SECTION  5.1     FURTHER  ASSURANCES.  From  time  to  time  after the date
hereof,  and  without any further consideration, POCC, the Subsidiaries, the GP,
the  MLP,  the  Operating  GP  and  the  Operating  Partnership  shall  execute,
acknowledge  and  deliver  all  such additional deeds, assignments, conveyances,
instruments,  notices,  releases,  acquittances and other documents, and will do
all such other acts and things, all in accordance with applicable law, as may be
necessary  or  appropriate  more  fully and effectively to vest in the Operating
Partnership  and  the MLP and their successors and assigns beneficial and record
title to the Contributed Assets hereby contributed and assigned to the Operating
Partnership or intended so to be and to more fully and effectively carry out the
purposes  and  intent  of  this  Agreement.

     SECTION  5.2     OTHER ASSURANCES. From time to time after the date hereof,
and  without  any  further  consideration, each of the parties to this Agreement
shall  execute, acknowledge and deliver all such additional instruments, notices
and  other  documents,  and  will  do  all  such  other  acts and things, all in
accordance with applicable law, as may be necessary or appropriate to more fully
and  effectively  carry  out  the  purposes  and  intent  of  this  Agreement.

                                   ARTICLE VI

                                  MISCELLANEOUS

     SECTION  6.1     HEADINGS;  REFERENCES;  INTERPRETATION.  All  article  and
section  headings  in  this  Agreement are for convenience only and shall not be
deemed to control or affect the meaning or construction of any of the provisions
hereof.  The  words  "hereof,"  "herein"  and  "hereunder"  and words of similar
import,  when  used in this Agreement, shall refer to this Agreement as a whole,
including  without  limitation,  all  exhibits  attached  hereto, and not to any
particular  provision  of  this  Agreement.  All  references herein to articles,
sections,  and  exhibits  shall,  unless  the  context  requires  a  different
construction,  be deemed to be references to the articles, sections and exhibits
of  this  Agreement,  respectively,  and  all  such Exhibits attached hereto are
hereby incorporated herein and made a part hereof for all purposes. All personal
pronouns  used  in  this  Agreement,  whether used in the masculine, feminine or
neuter  gender,  shall include all other genders, and the singular shall include
the  plural and vice versa. The use herein of the word "including" following any
general  statement,  term  or  matter  shall  not  be  construed  to  limit such
statement, term or matter to the specific items or matters set forth immediately
following  such word or to similar items or matters, whether or not non-limiting
language  (such  as  "without  limitation,"  "but  not  limited to," or words of
similar  import)  is  used with reference thereto, but rather shall be deemed to
refer  to  all  other  items  or  matters  that could reasonably fall within the
broadest  possible  scope  of  such  general  statement,  term  or  matter.

     SECTION  6.2     SUCCESSORS  AND  ASSIGNS.  This Agreement shall be binding
upon  and  inure  to  the  benefit  of  the  parties  signatory hereto and their
respective  successors  and  assigns.

     SECTION 6.3     NO THIRD PARTY RIGHTS. The provisions of this Agreement are
intended  to  bind  the  parties  signatory  hereto as to each other and are not
intended  to  and  do  not  create rights in any other person or confer upon any
other person any benefits, rights or remedies and no person is or is intended to
be  a  third  party  beneficiary  of  any  of  the provisions of this Agreement.


                                        4

     SECTION  6.4  COUNTERPARTS. This Agreement may be executed in any number of
counterparts,  all  of  which together shall constitute one agreement binding on
the  parties  hereto.

     SECTION  6.5  GOVERNING  LAW.  This  Agreement  shall  be  governed by, and
construed  in  accordance  with,  the  laws  of the State of Texas applicable to
contracts  made  and  to  be  performed  wholly within such state without giving
effect  to  conflict  of law principles thereof, except to the extent that it is
mandatory  that  the  law  of  some  other  jurisdiction,  shall  apply.

     SECTION  6.6  SEVERABILITY.  If any of the provisions of this Agreement are
held  by  any  court  of  competent jurisdiction to contravene, or to be invalid
under,  the  laws  of  any  political  body having jurisdiction over the subject
matter  hereof, such contravention or invalidity shall not invalidate the entire
Agreement.  Instead,  this Agreement shall be construed as if it did not contain
the  particular  provision  or  provisions  held to be invalid, and an equitable
adjustment  shall  be made and necessary provision added so as to give effect to
the  intention  of  the  parties  as  expressed in this Agreement at the time of
execution  of  this  Agreement.

     SECTION 6.7     AMENDMENT OR MODIFICATION. This Agreement may be amended or
modified  from  time  to  time  only by the written agreement of all the parties
hereto.

     SECTION  6.8     INTEGRATION.  This  Agreement,  together with that certain
Omnibus  Agreement  dated of even date herewith, to be entered into by and among
POCC, certain of POCC's subsidiaries, the MLP, the GP, the Operating Partnership
and  the  Operating  GP  (the  "Omnibus  Agreement"),  supersedes  all  previous
understandings  or agreements between the parties, whether oral or written, with
respect  to  its  subject matter. This document is an integrated agreement which
contains  the  entire  understanding  of  the  parties.  No  understanding,
representation,  promise or agreement, whether oral or written, other than those
contained in the Omnibus Agreement, is intended to be or shall be included in or
form part of this Agreement unless it is contained in a written amendment hereto
executed  by  the  parties  hereto  after  the  date  of  this  Agreement.

                    (Signatures  on  following  page)


                                        5

     IN  WITNESS  WHEREOF,  this Agreement has been duly executed by the parties
hereto  as  of  the  date  first  above  written.

                                         PENN OCTANE CORPORATION


                                         By:/s/ Richard Shore, Jr.
                                            ----------------------------------
                                              Richard  Shore,  Jr.,
                                              President

                                         RIO  VISTA  GP  LLC


                                         By:/s/  Richard  Shore,  Jr.
                                            ----------------------------------
                                              Richard  Shore,  Jr.,
                                              President


                                         RIO  VISTA  ENERGY  PARTNERS  L.P.

                                         By: RIO VISTA GP LLC,
                                         its  General  Partner


                                         By:/s/  Richard  Shore,  Jr.
                                            ----------------------------------
                                              Richard  Shore,  Jr.,
                                              President



                                         RIO  VISTA  OPERATING  GP  LLC


                                         By:/s/  Richard  Shore,  Jr.
                                            ----------------------------------
                                              Richard  Shore,  Jr.,
                                              President

                                         RIO VISTA OPERATING PARTNERSHIP L.P.

                                         By: Rio Vista Operating GP LLC,
                                             its General Partner

                                             By: Rio Vista Energy Partners L.P.,
                                                 its  sole  member

                                                 By: Rio Vista GP LLC,
                                                      its  General  Partner

                                                      By:/s/ Richard Shore, Jr.
                                                         -----------------------
                                                           Richard  Shore,  Jr.,
                                                           President


                                        6

                                    EXHIBIT A
                                    ---------

                              LIST OF SUBSIDIARIES

Penn-Octane de Mexico, S. de R.L. de C.V.

Termatsal, S. de R.L. de C.V.

Penn Octane International LLC



                                    EXHIBIT B



                              CONVEYANCE AGREEMENT

     Recording  Requested  by  and When Recorded Return to: Fulbright & Jaworski
L.L.P.,  300  Convent  St.,  Suite  2200, San Antonio, Texas, Attn: Christian G.
Herff.

                              CONVEYANCE AGREEMENT

     This  Conveyance  Agreement  (this "Conveyance"), effective as of 4:58 P.M.
Eastern  Time  on September 30, 2004 (the "Effective Date"), is from PENN OCTANE
CORPORATION,  a  Delaware corporation (herein called "Grantor"), and in favor of
RIO VISTA OPERATING PARTNERSHIP L.P., whose mailing address is 820 Gessner Road,
Suite  1285,  Houston,  TX  77024  (herein  called  "Grantee").

                                    ARTICLE I

                                 GRANTING CLAUSE

     1.1  GRANTING  CLAUSES.  Grantor  hereby  contributes,  conveys,  assigns,
transfers, delivers, and sets over unto Grantee, its successors and assigns, all
right,  title, interests and estate of Grantor in and to the following described
property,  to-wit:

     ALL OF THE ASSETS SET FORTH ON SCHEDULE A ATTACHED HERETO

     The  property  described  in  this  Section 1.1 shall be referred to herein
collectively  as  the  "Subject  Property".

     TO  HAVE  AND  TO  HOLD  the  Subject  Property,  subject  to the terms and
conditions  hereof,  unto  Grantee,  its  successors  and  assigns,  forever.

                                   ARTICLE II

                      ENCUMBRANCES AND WARRANTY DISCLAIMERS

     2.1  PERMITTED ENCUMBRANCES. This Conveyance is made and accepted expressly
subject  to  (a)  all  liens,  charges,  encumbrances,  contracts,  agreements,
instruments,  obligations, defects, restrictions, security interests, options or
preferential  rights  to  purchase,  adverse  claims,  reservations, exceptions,
easements,  rights-of-way,  conditions,  leases,  other  matters  affecting  the
Subject  Property  or  to  which  it  is  subject; and (b) to all matters that a
current  on  the  ground  survey  or  visual  inspection  would  reflect.

     2.2  CONTRIBUTION  AGREEMENT.  This Conveyance is expressly made subject to
the terms and conditions of that certain Contribution, Conveyance and Assumption
Agreement  dated  as of September 16, 2004, among Grantor, Grantee and the other
parties  thereto  (the  "Contribution  Agreement").  All  capitalized terms used
herein  shall  have  the  meanings  given  to  such  terms  in  the Contribution
Agreement, unless otherwise defined herein. Nothing contained in this Conveyance
shall  in  any way affect the provisions set forth in the Contribution Agreement
nor  shall  this  Conveyance expand or contract any rights or remedies under the
Contribution  Agreement. This Conveyance is intended only to effect the transfer
of the Subject Property to Grantee as provided for in the Contribution Agreement
and  shall  be  governed entirely in accordance with the terms and conditions of
the Contribution Agreement. In the event of a conflict between the terms of this
Conveyance  and  the  terms  of  the  Contribution  Agreement,  the terms of the
Contribution  Agreement  shall  prevail.

     2.3  DISCLAIMER  OF  WARRANTIES;  SUBROGATION. Except as expressly provided
herein  or  in  the  Contribution  Agreement,  this  Conveyance  is made, and is
accepted  by  Grantee, without warranty of title, express, implied or statutory,
and without recourse, but with full substitution and subrogation of Grantee, and
all  persons  claiming by, through, and under Grantee, to the extent assignable,
in  and  to all covenants and warranties by the predecessors in title of Grantor
and  with  full  subrogation of all rights accruing under applicable statutes of
limitation  or  prescription  and  all  rights of action of warranty against all
former owners of the Subject Property. Except as expressly provided herein or in
the  Contribution  Agreement,  any  covenants  implied  by  statute  or  by  the


                                      D-1

use  of  the  words  "convey",  "sell", "assign", "transfer", "deliver", or "set
over"  or  any  of  them  or any other words used in this Conveyance, are hereby
expressly  disclaimed,  waived  and  negated.


                                   ARTICLE III

                                  MISCELLANEOUS

     3.1  FURTHER ASSURANCES. Grantor and Grantee agree to take all such further
actions  and to execute, acknowledge and deliver all such further documents that
are necessary or useful in carrying out the purposes of this Conveyance. So long
as authorized by applicable law so to do, Grantor agrees to execute, acknowledge
and  deliver  to  Grantee  all  such  other  additional  instruments,  notices,
affidavits,  deeds,  conveyances,  assignments and other documents and to do all
such  other  and  further  acts and things as may be necessary or useful to more
fully and effectively grant, assign, convey, transfer and deliver to Grantee the
Subject Property conveyed hereby or intended so to be conveyed.

     3.2  SUCCESSORS  AND  ASSIGNS;  NO THIRD PARTY BENEFICIARY. This Conveyance
shall  be  binding  upon, and shall inure to the benefit of, Grantor and Grantee
and  their  successors  and  assigns.  The provisions of this Conveyance are not
intended  to  and  do  not create rights in any other person or entity or confer
upon  any  other person or entity any benefits, rights or remedies and no person
or  entity  is  or  is  intended  to  be a third party beneficiary of any of the
provisions  of  this  Conveyance.

     3.3  GOVERNING  LAW.  This  Conveyance  and the legal relations between the
parties  shall be governed by, and construed in accordance with, the laws of the
State  of  Texas, excluding any conflict of law rule which would refer any issue
to the laws of another jurisdiction, except when it is mandatory that the law of
the jurisdiction wherein the Subject Property is located shall apply.

     3.4  HEADINGS;  REFERENCES;  DEFINED  TERMS.  All  Section headings in this
Conveyance are for convenience only and shall not be deemed to control or affect
the meaning or construction of any of the provisions hereof. The words "hereof",
"herein"  and  "hereunder"  and  words  of  similar  import,  when  used in this
Conveyance,  shall  refer  to  this  Conveyance  as  a whole, including, without
limitation,  all  Schedules  and  Exhibits  attached  hereto,  and  not  to  any
particular  provision  of  this  Conveyance.

     3.5  COUNTERPARTS.  This  Conveyance  may  be  executed  in  any  number of
counterparts,  all  of  which together shall constitute one agreement binding on
the  parties  hereto.

     3.6  SEVERABILITY.  If any of the provisions of this Conveyance are held by
any  court  of competent jurisdiction to contravene, or to be invalid under, the
laws  of  any political body having jurisdiction over the subject matter hereof,
such  contravention  or  invalidity  shall  not invalidate the entire agreement.
Instead,  this  Conveyance  shall  be  construed  as  if  it did not contain the
particular  provision  or  provisions  held  to  be  invalid  and  an  equitable
adjustment  shall  be made and necessary provision added so as to give effect to
the  intention  of  the  parties  as expressed in this Conveyance at the time of
execution  of  this  Conveyance.


                                      D-2

     IN  WITNESS  WHEREOF, this Conveyance has been duly executed by the parties
hereto  on  the  dates  of the acknowledgments set forth below, to be effective,
however,  as  of  the  Effective  Date.

                                      GRANTOR:

                                      PENN  OCTANE  CORPORATION


                                      By:
                                         -----------------------------
                                            Richard  Shore,  Jr.,
                                            President

                                      GRANTEE:

                                      RIO VISTA OPERATING PARTNERSHIP L.P.

                                      By: Rio Vista Operating GP LLC,
                                          its General Partner

                                          By: Rio Vista Energy Partners L.P.,
                                              its sole member

                                              By: Rio Vista GP LLC,
                                                  its  General  Partner

                                                  By:
                                                     ---------------------------
                                                        Richard  Shore,  Jr.,
                                                        President


                                      D-3

THE STATE OF TEXAS    )
                      )
COUNTY OF ___________ )

     This  instrument was acknowledged before me on the ____ day of ___________,
2004,  by  ______________, ______________ of ________________________, on behalf
of and in [HIS/HER] capacity as __________ of ________________________.


                                                    ____________________________
                                                    NOTARY  PUBLIC

My Commission Expires:___________________


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                                   SCHEDULE A


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