Amended and Restated Line Letter
                        --------------------------------


                                                         September 15, 2004


Penn Octane Corporation
77-530 Enfield Lane
Building D
Palm Desert, CA  92211

Attention:  Mr. Jerome Richter

Gentlemen:

RZB FINANCE LLC ("RZB") and Penn Octane Corporation (the "Borrower") are parties
to  a  Line  Letter dated October 14, 1997 (as heretofore amended, the "Existing
Line  Letter").  The  Borrower  and RZB desire to amend and restate the Existing
Line  Letter.  Accordingly,  the  parties  hereto  agree  that the Existing Line
Letter  is  hereby amended and restated in its entirety as hereinafter set forth
in this Agreement (as amended, modified or supplemented from time to time, "this
Agreement"  or  "this  letter  agreement").  On  or  after the date hereof, when
counterparts  of  this Agreement shall have been executed by all parties hereto,
(a)  all  references to the "Agreement" and words of similar import in the other
Loan  Documents  shall be deemed to refer to the Existing Line Letter as amended
and  restated  hereby,  and  (b)  all outstanding loans and extensions of credit
under the Existing Line Letter shall be loans and extensions of credit under and
subject to the terms and conditions of this Agreement and the Loan Documents (as
hereinafter  defined).

          We  wish  to advise you of the terms and conditions upon which RZB may
in  its  sole  discretion  extend  credit  to  the  Borrower.

          1.   (a)  Subject  to  the provisions hereof, the Borrower may utilize
this  credit  facility  (the  "Credit  Facility") for demand loans ("Loans") and
issuance  of standby and commercial letters of credit ("L/C's") in the aggregate
principal  sum and face amount of up to Fifteen Million Dollars ($15,000,000) at
any one time outstanding.  Notwithstanding the foregoing, and without in any way
limiting  RZB's  sole  and  absolute discretion to determine whether to make any
Loan or issue any L/C, or refrain therefrom (as more fully set forth below), and
without  in  any way limiting RZB's absolute right to demand payment of any Loan
at  any  time or to change any of the Advance Rates (as hereinafter defined), at
any  time in RZB's sole discretion, the Borrower acknowledges that, with respect
to  each  specific  transaction of the Borrower financed by RZB pursuant hereto,
the  sum  of (i) the Loans made by RZB in connection with such transaction, (ii)
the aggregate face amount of L/Cs issued in connection therewith, plus (iii) the
aggregate  unreimbursed amount of all drawings under such L/Cs, shall not exceed
the  amount  obtained by applying the Advance Rates (the "Advance Rates") to the


                                      -1-

value  of  the  assets of the Borrower being financed by RZB in such transaction
(as  such  value  may  be  determined  by  RZB  in  its  sole  discretion).

          Within  the  above  Credit  Facility, there shall be a sublimit not to
exceed  Three Million Dollars ($3,000,000) at any time outstanding available for
the issuance of standby letters of credit from time to time for the financing of
the  purchase  of  diesel  fuel and gasoline fuel.  The terms and beneficiary of
each  such  letter  of  credit  shall  be  subject to RZB's approval in its sole
discretion.  Prior  to the issuance of any standby letter of credit described in
clause  (i)  above,  the  Borrower  shall deposit cash collateral with RZB in an
amount  equal  to  15% of the maximum face amount of such letter of credit.  The
Borrower  hereby  grants  to  RZB  a  lien on and security interest in such cash
collateral  and  all  deposit  accounts  in  which  such cash collateral and all
proceeds  thereof  shall  be  maintained  as security for all present and future
obligations  of  the  Borrower  to  RZB until the letter of credit expires or is
terminated and all obligations in connection therewith shall have been satisfied
in full in cash to the sole and absolute satisfaction of RZB, provided, however,
that  no  lien on and security interest in cash collateral shall be released nor
shall any cash collateral be released if any Event of Default under any security
agreement delivered in connection with this Agreement shall have occurred and be
continuing  (an  "Event of Default") or any event that with the giving of notice
or lapse of time or both would constitute such an Event of Default (a "Default")
shall  have  occurred  and  be  continuing  or any demand for payment of or cash
collateral  for  the obligations of the Borrower under the Credit Facility shall
have  been  made.

          Within  the  above  Credit  Facility, there shall be a sublimit not to
exceed  Five  Hundred  Thousand  Dollars  ($500,000)  at  any  time  outstanding
available for the issuance of standby letters of credit from time to time (i) to
secure  a  performance  bond with respect to Arizona and Nevada excise taxes and
(ii)  in  favor of Kinder Morgan to secure monthly lease obligations.  The terms
and beneficiary of each such letter of credit shall be subject to RZB's approval
in  its  sole discretion.  Prior to the issuance of any standby letter of credit
described in this paragraph, the Borrower shall deposit cash collateral with RZB
in  an amount equal to 100% of the maximum face amount of such letter of credit.
The  Borrower  hereby grants to RZB a lien on and security interest in such cash
collateral  and  all  deposit  accounts  in  which  such cash collateral and all
proceeds  thereof  shall  be  maintained  as security for all present and future
obligations  of  the  Borrower  to  RZB until the letter of credit expires or is
terminated and all obligations in connection therewith shall have been satisfied
in full in cash to the sole and absolute satisfaction of RZB, provided, however,
that  no  lien on and security interest in cash collateral shall be released nor
shall  any  cash collateral be released if any Default or Event of Default shall
have  occurred and be continuing or any demand for payment of or cash collateral
for  the  obligations  of the Borrower under the Credit Facility shall have been
made.

               (b)  For  purposes  hereof:

                    "Advance Rates" shall mean, with respect to each transaction
of  the  Borrower  financed  by  RZB  pursuant  hereto, the following respective
percentages  of  the  Borrower's  accounts  receivable or inventory which is the
subject  of  such transaction (provided, however, that RZB reserves the right to
change  any  or  all  of  the  following  percentages  or


                                      -2-

categories of assets in any way whatsoever, at its sole and absolute discretion,
at  any  time  and  from  time to time, with or without notice to the Borrower):

100%  of  CIF  cost  of  eligible inventory or 90% of the net face amount of the
Borrower's eligible accounts receivable (as such eligibility shall be determined
from  time  to  time  by  RZB in its sole and absolute discretion), whichever is
lower.

               (c)  The  Loans  shall  be evidenced by, and subject to the terms
and  conditions contained in, a single grid promissory note (the "Note") made by
the  Borrower  in form and substance satisfactory to RZB.  Interest on the Loans
shall  be  payable  at  the  rate  specified  in the Note (the "Interest Rate").

               (d)  Each  Loan  hereunder  shall be payable on demand, and in no
event  shall  any  Loan  be  outstanding  for  more  than  45  days.

               (e)  (i)   Each  L/C  shall be in form and substance satisfactory
to  RZB,  and, unless otherwise agreed by RZB, shall have an expiration date not
more  than  90  days  after  its  date  of  issuance.

                    (ii)  The  Borrower  shall  pay to RZB a fee with respect to
each  L/C  in  an amount equal to the greater of:  (1) a flat fee of $500, (2) a
fee  at  a  rate  per  annum equal to 2.5% of the maximum face amount of the L/C
(without  regard  to whether conditions to drawing may then be satisfied) or (3)
such  higher  amount  or  percentage  as  shall  be  agreed to in writing by the
Borrower  and  RZB with respect to L/Cs issued after the date of such agreement.
The  fee provided for in clauses (1), (2) and (3) shall be payable upon issuance
of  each L/C and, in the case of any L/C which as issued, amended or renewed has
an expiration date more than 90 days after its original date of issuance, on the
same  day in each calendar quarter thereafter if such L/C is outstanding on such
day.  After  any  such  fee  is  paid  it  shall  be  non-refundable.

               (f)  The  Borrower  shall  reimburse  RZB  for the amount of each
drawing  under  each  L/C  on demand, and shall pay interest on the unreimbursed
portion  of  each drawing as provided in the Continuing Agreement for Letters of
Credit  between  the  Borrower  and  RZB.

               (g)  This  credit  facility  may be terminated at any time at the
sole  and  absolute  discretion  of  RZB.

               (h)  Without  in  any  way  limiting  RZB's  sole  and  absolute
discretion  to  make  any  Loan  or issue any L/C, or refrain therefrom (as more
fully  set  forth  below), and without in any way limiting RZB's right to change
the  Advance  Rates  or  demand  payment of any Loan at any time in its sole and
absolute  discretion,  the Borrower agrees that it shall, from time to time, pay
the  Loans  and  reimbursement  obligations in respect of L/Cs and shall deliver
cash  collateral in respect of outstanding L/Cs, as and when necessary to cause:

the  sum  of  (1)  the  outstanding balance of all Loans, (2) the aggregate face
amount of all outstanding L/Cs, and (3) the aggregate unreimbursed amount of all
drawings  under  L/Cs  (as


                                      -3-

such  sum may be reduced by the amount of cash collateral maintained with RZB or
a  bank  designated  by  RZB  and pledged in respect of outstanding L/Cs) not to
exceed,  on  any date, the amount obtained by applying the Advance Rates as then
in  effect  to  the  aggregate  value  as  of  such date (as such value shall be
determined by RZB in its sole discretion) of all of the assets then owned by the
Borrower  (without  double  counting)  which  are  the  subject  of transactions
financed  by  RZB  pursuant hereto and are subject to a perfected first priority
security  interest  in  favor  of  RZB.

               (i)   The  Borrower  shall  pay  to  RZB  a  non-refundable
administration  fee  of  $50,000  on  the  date  hereof  and  thereafter on each
anniversary  of  the  date  hereof.

          2.   The  proceeds of the Loans and the L/C's shall be used to finance
the  purchase of inventory, including, within the sublimits set forth in Section
1(a) above, diesel fuel and gasoline fuel, from suppliers which is to be sold to
purchasers  acceptable  to  RZB  in  its sole discretion and accounts receivable
arising  from  the sale of inventory and other transactions acceptable to RZB in
its  sole  discretion.

          3.   Requests  for Loans under this Agreement and directions as to the
disposition  of  the  proceeds  of Loans shall be given in writing (including by
telecopy)  by  the  Borrower  to  RZB,  or  may  be  given  orally (including by
telephone),  provided any such oral communication shall be confirmed promptly to
RZB  in  writing.  Requests  for  L/C's  under  this Agreement shall be given in
writing  (including  telecopy)  by  the  Borrower  to  RZB  by the execution and
delivery  of an application satisfactory in form and substance to RZB.  Any such
Loan  so  made or L/C issued shall be conclusively presumed to have been made to
or  for  the  benefit  of,  or  for  the  account  of, the Borrower when made in
accordance with any such request or direction.  RZB may rely on any such request
or direction which it believes to be genuine, including, without limitation, any
oral  request  whether  or  not  confirmed  in  writing,  and RZB shall be fully
protected  in  so  doing without any duty to make any further inquiry as to such
genuineness  or  to  otherwise  act  in  good  faith  in  the  premises.

          4.   THE  BORROWER  AGREES  AND  ACKNOWLEDGES  THAT,  NOTWITHSTANDING
ANYTHING  TO THE CONTRARY CONTAINED OR IMPLIED IN THIS AGREEMENT, RZB SHALL HAVE
NO OBLIGATION TO MAKE ANY LOAN OR ISSUE ANY L/C, AND RZB SHALL HAVE THE SOLE AND
ABSOLUTE DISCRETION TO MAKE ANY LOAN OR ISSUE ANY L/C OR REFRAIN FROM MAKING ANY
LOAN  OR  ISSUING  ANY  L/C.  THE BORROWER FURTHER AGREES AND ACKNOWLEDGES THAT,
NOTWITHSTANDING ANYTHING TO THE CONTRARY CONTAINED OR IMPLIED IN THIS AGREEMENT,
ALL  OF  THE LOANS SHALL BE PAYABLE ON DEMAND, AND RZB MAY DEMAND PAYMENT OF ANY
LOAN  AND/OR  MAY  DEMAND CASH COLLATERAL FOR ANY OUTSTANDING L/C AT ANY TIME IN
ITS  SOLE  AND  ABSOLUTE  DISCRETION.

          5.   All  payments of principal, interest and other sums in connection
with  the  Loans  and L/C's shall be payable to RZB at such account as RZB shall
designate,  or  in the absence of such designation, to RZB at its office at 1133
Avenue  of the Americas, New York, New York 10036, in lawful money of the United
States in immediately available funds and without setoff or deduction.  Interest
and  fees shall be computed on the basis of a 360 day year and the actual number
of  days  elapsed.  In  the  event  that  such  computation  would  result  in a


                                      -4-

usurious  rate,  then  the interest or fee shall be recalculated on a 365 or 366
day  year,  as  the  case  may  be.

               All payments of principal, interest, and other sums in connection
with  this  letter  agreement,  the  Loans  and  L/C's  or  in  respect  of  any
participation  in  the  Credit Facility which may be sold in RZB's discretion to
any  participant  acceptable  to  RZB  (a  "Participant")  shall  be made by the
Borrower  to RZB or by RZB to the Participant, as applicable, free and clear of,
and  without deduction or withholding for, any and all present and future taxes,
levies,  duties  or withholdings of any kind or, if any deduction or withholding
from any amount payable hereunder or under any other Loan Document or in respect
of  the  participation of the Participant or in connection herewith or therewith
shall be legally required, such amount shall be increased by the Borrower as may
be  necessary  so  that  after  making  all  required deductions or withholdings
(including  deductions  or withholdings applicable to additional amounts payable
under  this paragraph 5) RZB or the Participant shall receive an amount equal to
the  amount  it  would have received had no such deductions or withholdings been
required. The Borrower shall pay to RZB promptly upon the Participant's request,
and  RZB  shall  promptly  pay  to  the  Participant,  any amount payable to the
Participant  pursuant to the preceding sentence, but RZB shall have no liability
under  this paragraph to the Participant for any amount which is not received by
RZB  from  the  Borrower.

          6.   Without  limiting the discretionary nature of the credit facility
hereunder, the making of each Loan and the issuance of each L/C shall be subject
to  the  fulfillment  (to  the  satisfaction of RZB) of the following conditions
precedent, provided that all of the following conditions precedent to the extent
           --------
relating  to RVEP and the Operating Partnership shall be waived by RZB until RZB
withdraws  such  waiver  and  gives  notice of such withdrawal to the Borrower :

               (a)  The  Borrower  shall  have executed and delivered to RZB the
Note(s) evidencing the Loans and a Continuing Agreement for Letters of Credit in
form  and  substance  satisfactory  to  RZB;

               (b)  The  Borrower,  Rio  Vista Energy Partners L.P. ("RVEP") and
Rio  Vista  Operating  Partnership  L.P.  (the  "Operating  Partnership")  (the
Borrower, RVEP and the Operating Partnership are collectively referred to as the
"Loan  Parties")  shall have delivered to RZB such documents of title, and other
instruments  and  documents, pertaining to the transaction of the Borrower which
is being financed in connection with such Loan or L/C, as RZB shall require, and
all  of  the  foregoing  shall  be  in  form  and  substance,  and  contain such
endorsements,  as  shall  be  satisfactory  to  RZB  in  all  respects;

               (c)  Each  Loan  Party  shall  have complied and shall then be in
compliance with all of the terms, covenants and conditions of this Agreement and
the  Loan  Documents  (as  hereinafter  defined  in  Section  11(c));

               (d)  The  representations  and  warranties  of  the  Loan Parties
contained in each of the Loan Documents shall be true and correct on the date of
such  Loan  or  L/C;


                                      -5-

               (e)  RZB's  continuing review of and continuing satisfaction with
the  business,  operations,  prospects,  properties, and condition, financial or
otherwise,  of  each  of  the  Loan  Parties;

               (f)  RZB  shall  have  received  (i)  a copy of all corporate and
partnership  action,  as  the  case may be, taken by each of the Loan Parties to
authorize  the  execution  and  delivery  of  the  agreements,  instruments  and
documents  pursuant  hereto  or in connection herewith, and (ii) if requested by
RZB, a legal opinion of counsel to the Loan Parties, together with such opinions
of  special  counsel  to  the  Loan  Parties as RZB shall request, and each such
opinion  shall  be  satisfactory  in  form  and  substance  to  RZB;

               (g)  RZB  shall have received the unlimited personal guarantee by
Mr.  Jerome  Richter  of payment of the obligations of the Borrower, in form and
substance  satisfactory  to  RZB,  and  the  personal financial statement of Mr.
Richter  in  form  and  substance  satisfactory  to  RZB;

               (h)  RZB  shall have received the unlimited guarantees by each of
RVEP  and  the  Operating  Partnership  of  payment  of  the  obligations of the
Borrower,  in  form  and  substance  satisfactory  to  RZB;

               (i)  (A)  Each  of  the  Loan  Parties  shall  have  executed and
delivered  to  RZB  a  general  security agreement granting RZB a first priority
perfected  lien  on  the  Collateral  (as defined therein) in form and substance
satisfactory  to  RZB;  and

                    (B)  RZB  shall  have  obtained  from  the Loan Parties duly
executed  Security  Agreement Questionnaires and such lien search reports as RZB
shall  request,  all  to  be  in  form  and  substance  satisfactory to RZB; and

                    (C)  RZB shall have filed such UCC financing statements with
respect  to  the  Loan  Parties  in  such  jurisdictions  as  RZB shall request;

               (j)  (A)  The  Borrower  and the Operating Partnership shall have
executed  and  delivered  to  RZB  amendments  or  supplements  to  the existing
Mortgages,  Deeds  of  Trust  and Security Agreements previously executed by the
Borrower, which shall be in form and substance satisfactory to RZB, granting RZB
a  first  priority  mortgage  lien and deed of trust on the collateral described
therein,  including  without  limitation, the terminal in Brownsville, Texas and
all  pipelines  and  evidencing  the  assumption  thereof  by  the  Operating
Partnership;  and

                    (B)  Such  amendments  or  supplements  shall have been duly
filed  and  recorded  in  all  filing  offices  deemed  necessary  by  RZB;

               (k)  The  Loan  Parties shall have executed and/or delivered such
agreements,  instruments  and documents, including, without limitation, consents
of  third  parties and lessor, titles insurance policy endorsements and searches
and surveys, as RZB shall request in connection with the Security Agreements and
amendments  or  supplements  referred to in the two preceding paragraphs (i) and
(j);


                                      -6-

               (l)  The Operating Partnership shall have delivered to RZB copies
of  notices  to  its  account  debtors (including without limitation PMI Trading
Limited  and  its  affiliates), duly executed by such account debtors, directing
that  payment  be  made  directly  to  RZB;

               (m)  The  Loan  Parties  shall  have  delivered  such evidence of
insurance  and  loss  payable  endorsements  as  RZB  may  require;

               (n)  The Loan Parties shall have delivered copies of all of their
supply  and  sales  contracts having a term exceeding 30 days, certified as true
and  complete  by  a  senior  officer;

               (o)  The  Loan Parties shall have instituted lockbox arrangements
satisfactory  to  RZB  in  its  sole  discretion;

               (p)  The  Borrower  shall have delivered to RZB copies, certified
as  true  and complete, of all agreements, instruments and documents, including,
without  limitation,  all  registrations and filings with and notices to the SEC
and  any  other  governmental  authority,  relating  to  the  establishment,
capitalization, operation, administration and management of the Loan Parties and
their  affiliates  and  the transfer by the Borrower of any or all of its assets
and  business  to  any Loan Party or affiliate thereof, and all of the foregoing
shall  be  satisfactory  in  form  and  substance  to  RZB;

               (q)  All  legal  matters  incident  to  such Loan or L/C shall be
reasonably  satisfactory  to  counsel  to  RZB.

          7.   As  long  as  any  of the Loans or L/C's or any other obligations
hereunder  shall  be  outstanding,  the Borrower shall comply with the following
covenants,  provided  that  until  RZB  notifies  the  Borrower  in writing, the
covenants  shall  not  apply  to  RVEP  or  the  Operating  Partnership:

               (a)  Furnish  to RZB within 120 days after the end of each fiscal
year  a  copy  of  the  audited  financial  statements  of the Borrower and RVEP
prepared  in  conformity  with  generally  accepted  accounting  principles
consistently  applied  and  certified without qualification by the relevant Loan
Party's  independent  public  accountants.

               (b)  Furnish  to  RZB, each certified as true and complete in all
respects  by the Borrower's chief financial officer or the person acting in such
capacity,  (i) on a quarterly basis not later than 60 days after the end of each
quarter, a copy of the financial statements of each Loan Party for the preceding
quarter; (ii) on a weekly basis or more frequently if required by RZB, each Loan
Party's  current  inventory  report,  and  on  a  daily basis, each Loan Party's
loading rack tickets evidencing delivery of the commodity and resulting accounts
receivable  which  are  the  subject of any underlying financing; and (iii) on a
monthly  basis  not later than 30 days after the end of each month, a profit and
loss  statement  of  each  Loan  Party.


                                      -7-

               (c)  Furnish,  to RZB such other information concerning each Loan
Party's  business,  properties, condition or operations, financial or otherwise,
as  RZB may from time to time reasonably request and copies of all reports filed
with  the  Securities  and  Exchange  Commission  from  time  to  time.

               (d)  Maintain  and  preserve,  and cause each other Loan Party to
maintain  and preserve, its corporate existence, and remain in the same lines of
business  as  on  the  date  hereof.

               (e)  Except  as  set  forth on Schedule 7(e) hereto, the Borrower
shall  not,  and  shall  cause  each  other Loan Party not to, create, assume or
permit  to  exist  any  lien,  security  interest,  mortgage,  charge  or  other
encumbrance of any nature whatsoever on any of its properties or assets, whether
now  owned  or  hereafter  acquired,  except  in  favor  of  RZB.

               (f)  The  Borrower  shall cause Rio Vista on a consolidated basis
and  the  Operating Partnership to maintain an excess of total assets over total
liabilities  as  determined  in  accordance  with  generally accepted accounting
principles  of  at  least  $9,000,000  at  all  times.

               (g)  The  Borrower shall not, and shall cause each Loan Party not
to,  declare  or  make at any time any dividend payment or other distribution of
assets,  properties,  cash,  rights, obligations or securities on account of any
shares  of any class of capital stock of the Borrower or such Loan Party, as the
case  may  be, or its partnership interests or other equity, or purchase, redeem
or  otherwise acquire for value (or permit any of its subsidiaries to do so) any
shares  of  any  class  of  capital  stock or the partnership interests or other
equity  of  the  Borrower  or  such other Loan Party, as the case may be, or any
warrants,  rights  or  options  to acquire such shares, partnership interests or
other  equity now or hereafter outstanding, without the prior written consent of
RZB  unless, before and after giving effect to the payment of any such dividends
or  distributions,  such  Loan Party shall be in compliance with all obligations
and  covenants  contained  in this agreement and the other Loan Documents and no
Default or Event of Default shall have occurred and be continuing.  The Borrower
shall  deliver  to RZB a certificate from the Borrower's chief financial officer
or  the  person  acting  in  such  capacity  on  the earlier of the date of each
delivery of the quarterly financial statements under Section 7(b) hereof and the
date  such  quarterly financial statements are required to be delivered, setting
forth  the  amount  of  all  dividends and distributions paid by each Loan Party
during  the  immediately  preceding  fiscal quarter, together with a calculation
with  respect thereto showing compliance with the covenant in this Section 7(g).

          8. Notwithstanding anything to the contrary contained herein or in any
other Loan Document, including without limitation the General Security Agreement
dated  October  17,  1997  between the Borrower and RZB and the General Security
Agreement  between  the  Operating  Partnership  and  RZB:

               (a)  Provided that no Event of Default under any Loan Document
shall have occurred and be continuing, no event that with the giving of notice
or lapse of time or both would constitute such an Event of Default shall have
occurred and be continuing and no demand for payment of any obligations of the
Borrower shall have been made by RZB, RZB shall, upon


                                      -8-

request of the Borrower, execute and deliver an agreement reasonably
satisfactory to RZB subordinating RZB's mortgage lien and security interest on
the land, buildings and fixtures (but no other assets contained thereon or
therein) constituting (x) the Borrower's terminal in Brownsville, Texas and (y)
the Borrower's pipeline, to any mortgage lien and security interest of a third
party unaffiliated with the Borrower (the "New Lender") which secures financing
provided by the New Lender to the Borrower after the date hereof.  Such
agreement shall contain a covenant by the New Lender to transport at no cost to
RZB from such terminal and/or through such pipeline all inventory of the
Borrower or the Operating Partnership financed by RZB.  The foregoing is not a
consent by RZB to any additional financing or indebtedness of the Borrower.

               (b)  In the event the Borrower intends to obtain additional
financing or incur additional indebtedness, the Borrower shall notify RZB and
request RZB's consent.  RZB agrees to consider such request, but the Borrower
expressly acknowledges and agrees that: (x) RZB shall have sole discretion to
grant or deny such consent or impose conditions on the grant of such consent and
(y) RZB has not committed or agreed to grant such consent, and such consent
shall be effective only if in writing and executed by RZB.

          9.   The  Borrower  represents  and  warrants to RZB and covenants and
agrees  with  RZB  that, with respect to each account receivable of the Borrower
and  any other Loan Party financed by RZB pursuant hereto, there is not nor will
there  be  at  any  time,  any  counterclaim,  dispute  or  any  other matter or
circumstance  whatsoever  which  could  give rise to a right of set-off or other
adverse  claim  that  could  be  asserted  by  the  account debtor to reduce its
obligation  to  pay  under  such  account  receivable.

          10.  The  Borrower  represents  and  warrants to RZB and covenants and
agrees with RZB that the business of RVEP is and shall be solely to be a holding
company  whose  sole  assets  are  and  shall  be its interests in the Operating
Partnership.

          11.  (a)  No  delay  on  the  part  of  RZB  in  exercising any of its
options,  powers  or rights, or partial or single exercise thereof, irrespective
of  any  course  of  dealing,  shall  constitute a waiver thereof.  The options,
powers and rights of RZB specified in the Loan Documents (as hereinafter defined
in Section 11(c)) are in addition to those otherwise created by law or under any
other  agreement  between any Loan Party and RZB.  No amendment, modification or
waiver of any provision of any Loan Document to which any Loan Party is a party,
nor  consent  to  any departure by any Loan Party therefrom, shall be effective,
unless  the  same  shall  be  in  writing and signed by RZB.  Any such waiver or
consent shall be effective only in the specific instance and for the purpose for
which  given.  No  consent  to or demand on any Loan Party in any case shall, of
itself,  entitle it to any other or further notice or demand in similar or other
circumstances.

               (b)  This  Agreement  and  the  other  Loan  Documents embody the
entire  agreement  and  understanding between RZB and Loan Parties and supersede
all  prior  agreements and understandings relating to the subject matter hereof.
THIS  WRITTEN  AGREEMENT  (AND  THE  OTHER  LOAN DOCUMENTS) REPRESENTS THE FINAL
AGREEMENT  AMONG  THE  PARTIES HERETO AND THE OTHER LOAN PARTIES WITH RESPECT TO


                                      -9-

THE  MATTERS  COVERED HEREBY AND THEREBY AND MAY NOT BE CONTRADICTED BY EVIDENCE
OF  PRIOR,  CONTEMPORANEOUS  OR  SUBSEQUENT  ORAL  AGREEMENTS  OF  THE  PARTIES.

               (c)  The  Borrower  agrees to pay all costs and expenses incurred
or  payable  by  RZB  and  the  Participant  in connection with the preparation,
administration, interpretation, enforcement or collection of this Agreement, the
Note,  any  Participation  Agreement between RZB and the Participant (as amended
from  time  to  time,  the  "Participation  Agreement"),  the  L/C's  and  any
applications  or  other  agreements  pertaining  to  the  issuance  thereof, the
security  agreements  with  and guarantees from the Loan Parties, the mortgages,
and  amendments  and  supplements  referred  to  herein, and all other documents
executed  and delivered in connection herewith or therewith (such agreements and
documents,  including all amendments, modifications and supplements of or to all
such  agreements  and documents are herein referred to as the "Loan Documents"),
including,  without  limitation,  costs  of  examination  and  audit of the Loan
Parties'  books and records and of the collateral security for the Loans and L/C
reimbursement  obligations,  and  court costs and reasonable attorneys' fees and
disbursements.

               (d)  (i)   If  RZB  or the Participant shall have determined that
the  applicability  of  any  law,  rule,  regulation  or  guideline (domestic or
foreign)  adopted  (whether  before  or  after  the  date hereof) pursuant to or
arising  out  of  the  July  1988  report  of  the  Basle  Committee  on Banking
Regulations  and  Supervisory  Practices  entitled "International Convergence of
Capital  Measurement  and  Capital  Standards",  or  the adoption after the date
hereof  of  any  other  law, rule, regulation or guideline (domestic or foreign)
regarding  capital  adequacy,  or  any  change in any of the foregoing or in the
enforcement  or  interpretation or administration of any of the foregoing by any
court  or  any governmental authority, central bank or comparable agency charged
with  the enforcement or interpretation or administration thereof, or compliance
by  RZB  or the Participant or any corporation or other entity which directly or
indirectly  controls  RZB  or  the  Participant  (each such corporation or other
entity  is  hereinafter  referred  to as a "Controlling Person") (or any lending
office of RZB or the Participant or any Controlling Person), with any request or
directive regarding capital adequacy (whether or not having the force of law) of
any  such court, authority, central bank or comparable agency, has or would have
the  effect of reducing the rate of return on RZB's or the Participant's (as the
case  may  be)  capital  or on the capital of a Controlling Person, if any, as a
consequence  of  its  issuance  or maintenance of any L/C or its obligations (if
any)  under  this Agreement or the Participation Agreement to a level below that
which  RZB or the Participant or such Controlling Person could have achieved but
for  such  applicability,  adoption,  change  or  compliance  (taking  into
consideration  RZB's  or the Participant's (as the case may be) policies and the
policies  of  such  Controlling  Person  with respect to capital adequacy) by an
amount deemed by RZB or the Participant to be material, then, upon demand by RZB
                                                        ----
or the Participant, the Borrower shall pay to RZB from time to time as specified
by  RZB  or the Participant such additional amount or amounts as will compensate
RZB  or  the  Participant  or  such  Controlling  Person  for any such reduction
suffered.  Any  such  amount  paid  to  RZB  relating  to  the  Participant or a
Controlling  Person  of  the  Participant  shall  be promptly paid by RZB to the
Participant  pursuant  to  the  Participation  Agreement  between  them.


                                      -10-

                    (ii)  If  any  change  in law, rule, regulation or guideline
(domestic  or  foreign)  or in the enforcement, interpretation or administration
thereof  by  any court or any governmental authority, central bank or comparable
agency  charged  with  the interpretation or administration thereof shall at any
time  (A)  impose,  modify  or  deem  applicable any reserve, special deposit or
similar  requirement (including, without limitation, pursuant to Regulation D of
the  Board of Governors of the Federal Reserve System) against letters of credit
issued  by  RZB  or  participations  therein purchased by the Participant or (B)
subject  letters  of credit issued by RZB or participations therein purchased by
the  Participant  to any assessment or other cost imposed by the Federal Deposit
Insurance  Corporation  or  any  successor  thereto  or (C) impose on RZB or the
Participant  any  other or similar condition regarding this Agreement or any L/C
or the Participation Agreement, the obligations (if any) of RZB hereunder or the
obligations  of the Participant under the Participation Agreement and the result
of  any  event  referred to in clause (A), (B) or (C) above shall be to increase
the  cost to RZB or the Participant of agreeing to issue, issuing or maintaining
or  confirming any L/C or making, funding or maintaining (or agreeing to fund or
maintain) drawings under any L/C or of participating in any L/C or to reduce any
accounts  receivable  by  RZB or the Participant hereunder or by the Participant
under  the  Participation  Agreement  by  an amount which RZB or the Participant
shall  deem  to  be  material  (which increase in cost or reduction shall be the
result  of  the reasonable allocation by RZB or the Participant of the aggregate
of  such  cost  increases  or reductions resulting from such events), then, upon
                                                                      ----
demand  by  RZB  or  the Participant, the Borrower shall pay to RZB from time to
time  as  specified  by  RZB  or  the  Participant  (as  the  case may be), such
additional  amount  or amounts as will compensate RZB or the Participant (as the
case  may  be)  for  such increased cost from the date of such change.  Any such
amount  paid to RZB relating to the Participant shall be promptly paid by RZB to
the  Participant  pursuant  to  the  Participation  Agreement between them.  The
Borrower's  obligation  to  pay  compensation  contained in this subsection (ii)
shall  be  applicable  as  well  to  any  amount RZB may be obligated to pay any
financial  institution  which confirms or advises any L/C and which incurs or is
subjected  to  any increased cost or reduction of amounts receivable as a result
of  the  imposition,  modification or applicability of any such reserve, special
deposit  or  similar requirement, the subjecting of L/C's to any such assessment
or  other  cost,  or  the  imposition  of  any  such other or similar condition.

                    (iii) The  provisions  of  this subsection (d) shall survive
the  termination  of  this  Agreement.

                    (iv)  RZB  or  the  Participant  shall  notify  the Borrower
within  3  months  after it becomes aware of its right to claim any amount under
paragraphs  (d)(i)  or  (ii) above, provided that (A) if such lender fails to so
                                    --------
notify  the  Borrower  within  such  3  month  period,  such lender shall not be
entitled  to  claim  any  additional amounts pursuant to this subsection for any
period ending on a date which is prior to 3 months before such notification plus
any  additional  period  of  retroactive  effect of the law, rule, regulation or
guideline referred to in paragraph (d)(i) or (ii) above, and (B) neither RZB nor
the  Participant  shall  have  any  right to assert a claim for any amount under
paragraphs (d)(i) or (ii) after the date which is 3 months after payment in full
of  all  Loans,  obligations in respect of L/C's and other obligations hereunder
and  the  termination  of  this  Agreement.


                                      -11-

               (e)  The  Loan  Documents  to  which  the  Borrower  and the Loan
Parties  are  a  party shall be binding on the Borrower and the Loan Parties and
their  respective  successors and assigns, and shall inure to the benefit of RZB
and  its  successors  and assigns, provided that the Borrower shall not have the
right  to  assign  its  rights hereunder or thereunder or any interest herein or
therein  without  RZB's  prior  written  consent.

               (f)  In  addition  to the rights granted to it by applicable law,
RZB has the right to set-off and apply to any of the Borrower's and Loan Parties
obligations hereunder and under the Loan Documents any amount received by it for
the  Borrower or any of the Loan Parties.  The Participant shall have a right of
set-off  and  banker's lien to the same extent as if its participation under the
Participation  Agreement  were  a  direct  loan  to  the  Borrower.

               (g)  THIS  AGREEMENT  SHALL  BE  CONSTRUED IN ACCORDANCE WITH AND
GOVERNED  BY  THE  LAW OF THE STATE OF NEW YORK (WITHOUT REGARD TO PRINCIPLES OF
CONFLICTS  OF  LAW).

                    CONTRARY  TO  THE  EXPRESS  AGREEMENT OF THE PARTIES IN THIS
SECTION  11(G)  HEREOF,  IF THE LAWS OF ANY STATE OTHER THAN NEW YORK, INCLUDING
THE  LAWS  OF  THE  STATE OF TEXAS, SHALL BE DETERMINED TO BE APPLICABLE TO THIS
AGREEMENT, THE NOTE OR THE OTHER LOAN DOCUMENTS, IT IS THE INTENT OF THE PARTIES
HERETO  TO  COMPLY  WITH  ALL  APPLICABLE  USURY  LAWS AND TO LIMIT ALL INTEREST
CONTRACTED  FOR,  RESERVED,  CHARGED OR RECEIVED UNDER THE LOAN DOCUMENTS TO THE
MAXIMUM  NONUSURIOUS  RATE  OF  INTEREST  PERMITTED  BY  APPLICABLE LAW.  IF THE
APPLICABLE  COMMON  LAW  AND  PRINCIPLES  OF EQUITY AND CONSTITUTIONS, STATUTES,
RULES,  REGULATIONS  AND  ORDERS  OF  GOVERNMENTAL  BODIES  AND AUTHORITIES, AND
ORDERS, WRITS, DECISIONS, INJUNCTIONS AND DECREES OF ALL COURTS, ARBITRATORS AND
GOVERNMENTAL  INSTRUMENTALITIES  (THE  "APPLICABLE  LAW")  IS  EVER  JUDICIALLY
INTERPRETED  SO  AS  TO  RENDER  USURIOUS  ANY  AMOUNT  CALLED  FOR  UNDER OR IN
CONNECTION  WITH THE NOTES, THIS AGREEMENT AND THE LOAN DOCUMENTS, OR CONTRACTED
FOR,  CHARGED,  TAKEN,  RESERVED  OR  RECEIVED  WITH RESPECT TO THE TRANSACTIONS
REFERRED  TO  HEREIN OR THEREIN, OR IF DEMAND OF OR ACCELERATION OF THE MATURITY
OF  THE NOTE OR IF ANY PREPAYMENT BY BORROWER OR ANY OF THE LOAN PARTIES RESULTS
IN  BORROWER  OR  LOAN  PARTIES  OR  ANY  OTHER  PERSON HAVING PAID ANY INTEREST
(HOWEVER  DENOMINATED)  IN EXCESS OF THAT PERMITTED BY LAW FOR THE ACTUAL PERIOD
THE  NOTE  AND  THE  OBLIGATIONS  OF  THE  BORROWER  AND  THE  LOAN  PARTIES ARE
OUTSTANDING,  THEN IT IS THE BORROWER'S, THE LOAN PARTIES' AND RZB'S INTENT THAT
ALL  EXCESS  AMOUNTS  THERETOFORE  RECEIVED  BY  RZB  SHALL  BE  CREDITED ON THE
PRINCIPAL BALANCE OF THE NOTE (OR, IF THE NOTE HAS BEEN OR WOULD THEREBY BE PAID
IN  FULL,  REFUNDED  TO THE BORROWER OR THE LOAN PARTIES), AND THE PROVISIONS OF
THE NOTE AND THIS AGREEMENT IMMEDIATELY SHALL BE DEEMED REFORMED AND THE AMOUNTS
THEREAFTER  COLLECTIBLE  UNDER  THE  NOTE,  THIS  AGREEMENT  AND  THE OTHER LOAN
DOCUMENTS  REDUCED, WITHOUT THE NECESSITY OF THE EXECUTION OF ANY NEW DOCUMENTS,
SO AS TO COMPLY WITH THE APPLICABLE LAW, BUT SO AS TO PERMIT THE RECOVERY OF THE
FULLEST AMOUNT OTHERWISE CALLED FOR UNDER THE NOTE, THIS AGREEMENT AND THE OTHER
LOAN  DOCUMENTS  FOR  THE  ACTUAL  PERIOD  THE NOTE AND OTHER OBLIGATIONS OF THE
BORROWER  AND  THE  LOAN  PARTIES  ARE  OUTSTANDING.

               (h)  THE  BORROWER  AND  THE  LOAN  PARTIES HEREBY AGREE THAT ANY
LEGAL  ACTION  OR PROCEEDING AGAINST THE BORROWER OR ANY LOAN PARTY WITH RESPECT
TO THIS AGREEMENT OR ANY OTHER LOAN DOCUMENT MAY BE BROUGHT IN THE COURTS OF THE
STATE  OF  NEW  YORK


                                      -12-

IN  THE  CITY  OF  NEW  YORK OR OF THE UNITED STATES OF AMERICA FOR THE SOUTHERN
DISTRICT  OF  NEW  YORK AS RZB MAY ELECT, AND, BY EXECUTION AND DELIVERY HEREOF,
EACH  OF THE BORROWER AND THE LOAN PARTIES ACCEPT AND CONSENT TO, FOR ITSELF AND
IN  RESPECT  TO ITS PROPERTY, GENERALLY AND UNCONDITIONALLY, THE JURISDICTION OF
THE  AFORESAID  COURTS  AND  AGREES  THAT  SUCH JURISDICTION SHALL BE EXCLUSIVE,
UNLESS WAIVED BY RZB IN WRITING, WITH RESPECT TO ANY ACTION, CLAIM OR PROCEEDING
BROUGHT  BY  IT AGAINST RZB AND ANY QUESTIONS RELATING TO USURY.  NOTHING HEREIN
SHALL  LIMIT  THE RIGHT OF RZB TO BRING PROCEEDINGS AGAINST THE BORROWER AND THE
LOAN PARTIES IN THE COURTS OF ANY OTHER JURISDICTION.  THE BORROWER AND THE LOAN
PARTIES  AGREE THAT SECTIONS 5-1401 AND 5-1402 OF THE GENERAL OBLIGATIONS LAW OF
THE  STATE  OF NEW YORK SHALL APPLY TO THIS AGREEMENT AND, TO THE MAXIMUM EXTENT
PERMITTED  BY  LAW,  WAIVES  ANY  RIGHT  TO  STAY  OR  TO  DISMISS ANY ACTION OR
PROCEEDING  BROUGHT  BEFORE  SAID  COURTS  ON THE BASIS OF FORUM NON CONVENIENS.
                                                           ----- --- ----------

               (i)  AFTER  REVIEWING  THIS  PROVISION  SPECIFICALLY  WITH  ITS
RESPECTIVE  COUNSEL,  EACH  OF  THE  BORROWER,  THE  LOAN PARTIES AND RZB HEREBY
KNOWINGLY,  VOLUNTARILY  AND INTENTIONALLY WAIVES ANY AND ALL RIGHTS IT MAY HAVE
TO  A  TRIAL  BY  JURY IN RESPECT OF ANY LITIGATION BASED ON, OR ARISING OUT OF,
UNDER, OR IN CONNECTION WITH, THIS AGREEMENT OR ANY COURSE OF CONDUCT, COURSE OF
DEALING, STATEMENTS (WHETHER VERBAL OR WRITTEN), OR ACTIONS OF THE BORROWER, THE
LOAN PARTIES OR RZB.  THIS PROVISION IS A MATERIAL INDUCEMENT FOR RZB MAKING THE
LOANS  TO  THE  BORROWER  AND  THE  LOAN  PARTIES.

               (j)  NO  CLAIM  MAY  BE MADE BY THE BORROWER OR ANY LOAN PARTY OR
ANY  OTHER  PERSON  AGAINST  RZB  OR THE PARTICIPANT OR THE OFFICERS, DIRECTORS,
EMPLOYEES  OR  AGENTS  OF  RZB  OR  THE  PARTICIPANT  FOR ANY SPECIAL, INDIRECT,
PUNITIVE OR CONSEQUENTIAL DAMAGES IN RESPECT OF ANY CLAIM FOR BREACH OF CONTRACT
OR  ANY  OTHER THEORY OF LIABILITY ARISING OUT OF OR RELATED TO THE TRANSACTIONS
CONTEMPLATED  BY  THIS  AGREEMENT,  ANY  OBLIGATIONS OF THE BORROWER OR ANY LOAN
PARTY  AND/OR  ANY OF THE COLLATERAL, OR ANY ACT, OMISSION OR EVENT OCCURRING IN
CONNECTION  THEREWITH,  AND  THE  BORROWER  AND  EACH  LOAN PARTY HEREBY WAIVES,
RELEASES  AND  AGREES  NOT  TO  SUE  UPON  ANY  CLAIM  FOR  ANY  SUCH  DAMAGES.

               (k)  Notwithstanding  the  Participation  Agreement, the Borrower
shall  be  permitted, except as otherwise expressly provided herein, to send all
notices, requests and documents solely to RZB and not to the Participant, and to
act  on  instruction,  requests  and  directions  from  RZB alone.  The Borrower
acknowledges  that  pursuant to the Participation Agreement:  (i) RZB shall have
no obligation to make or issue any Loan or L/C unless approved by RZB and by the
Participant  in  accordance  with  the  Participation Agreement, in each case in
their  respective  sole  and  absolute  discretion,  and  (ii) either RZB or the
Participant shall have the right to cause RZB to make any demand under Section 4
of  this  Agreement.

               (l)  The Borrower shall simultaneously deliver to the Participant
at the address provided for in written notice from RZB or the Participant to the
Borrower  a  copy  of  each  request  for a Loan or L/C given to RZB pursuant to
Section  3  of  this Agreement and all financial statements, notices and reports
delivered  to  RZB  pursuant  to  or  in  connection  with  this  Agreement,


                                      -13-

together with all such documents and information relating to such request as the
Participant shall require.  The Borrower expressly consents to RZB's delivery to
the Participant of any documents and information relating to the Borrower now or
hereafter  in  the  possession  of  RZB.

               (m)  At  any  time when all Loans shall have been paid in full in
cash,  all L/C's shall have expired, terminated or been cash collateralized, and
all  other  obligations hereunder shall have been satisfied, in each case to the
sole  and  absolute  satisfaction  of  RZB,  the Borrower may terminate the Loan
Documents,  and  RZB will take reasonable steps to release the liens in favor of
RZB;  provided,  however,  that  notwithstanding  any  termination  of  the Loan
      --------   -------
Documents,  the  provisions  of  Section  11  of  this  Agreement  shall survive
termination  of  this  Agreement.


                                      -14-

                                               Very truly yours,

                                               RZB FINANCE LLC


                                               By:  /s/ Pearl Geffers
                                                  ------------------------------
Accepted and Agreed to on this 15th day of        Name:  Pearl Geffers
                               ----               Title: First Vice President
September, 2004
- ---------


                                               By:  /s/ Griselda Alvizo
                                                  ------------------------------
                                                  Name:  Griselda Alvizo
                                                  Title: Vice President

PENN OCTANE CORPORATION


By:  /s/ Jerome B. Richter
    ---------------------------------
    Name:  Jerome B. Richter
    Title:  Chief Executive Officer


The undersigned hereby acknowledges and consents
to the foregoing Amended and Restated Line Letter
and hereby confirms that the Guaranty and
Agreement dated as of October 14, 1997 is hereby
ratified and confirmed in all respects and shall
extend to all indebtedness, liabilities and
obligations under or in connection with the
foregoing Amended and Restated Line letter, as
amended, modified or supplemented from time to
time.


/s/ Jerome B. Richter
- -----------------------------
    Jerome Richter


                                      -15-





                                  Schedule 7(e)

                                      Liens


                                      -16-