UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                    FORM 8-K
                                 CURRENT REPORT

                       Pursuant to Section 13 or 15(d) of
                      the Securities Exchange Act of 1934


      Date of Report (Date of earliest event reported):  September 17, 2004


                             PENN OCTANE CORPORATION
             (Exact name of registrant as specified in its charter)


          Delaware                     000-24394             52-1790357
          (State  of                   (Commission           (IRS  Employer
          Incorporation)               File Number)          Identification No.)


          77-530  Enfield  Land,  Bldg  D
          Palm  Desert,  California                          92211
          (Address of principal executive offices)           (Zip Code)

                                 (760) 772-9080
              (Registrant's telephone number, including area code)

                                       N/A
          (Former Name or Former Address, if Changed Since Last Report)


     Check  the  appropriate  box  below  if  the Form 8-K filing is intended to
simultaneously  satisfy the filing obligation of the registrant under any of the
following  provisions  (see  General  Instruction  A.2.  below):

     [ ] Written communications pursuant to Rule 425 under the Securities Act
         (17  CFR  230.425)

     [ ] Soliciting  material  pursuant  to Rule 14a-12 under the Exchange Act
         (17 CFR  240.14a-12)

     [ ] Pre-commencement  communications  pursuant  to  Rule  14d-2(b)  under
         the Exchange  Act  (17  CFR  240.14d-2(b))

     [ ] Pre-commencement  communications  pursuant  to  Rule  13e-4(c)  under
         the Exchange  Act  (17  CFR  240.13e-4(c))


                                  Page 1 of 6

Item 8.01. Other Events

On  September 17, 2004, Penn Octane Corporation issued a press release regarding
the  declaration of effectiveness by the Securities and Exchange Commission of a
registration  statement  on  Form 10 filed by Rio Vista Energy Partners L.P. and
the expected completion date of the proposed spin-off of the common units of Rio
Vista  Energy  Partners  L.P.  to stockholders of Penn Octane Corporation.   The
press  release  is  attached  hereto  as Exhibit 99.1 and incorporated herein by
reference.

Item 9.01.  Financial Statements And Exhibits

     (c)  Exhibits

          99.1 Press  release  dated  September  17,  2004


                                  Page 2 of 6

                                   SIGNATURES

     Pursuant  to  the  requirements of the Securities Exchange Act of 1934, the
registrant  has  duly  caused  this  report  to  be  signed on its behalf by the
undersigned  hereunto  duly  authorized.

                                          PENN OCTANE CORPORATION


                                          By: /s/ Ian T. Bothwell
                                             -------------------------
                                               Name: Ian T. Bothwell
                                               Title: Vice President, Treasurer,
                                                 Assistant  Secretary,  Chief
                                                 Financial Officer and Principal
                                                 Accounting Officer

Date: September 20, 2004


                                  Page 3 of 6


                                  EXHIBIT INDEX


Exhibit  No.          Description                              Page  No.
- ------------          -----------                              ---------

        99.1          Press Release dated September 17, 2004           5


                                  Page 4 of 6