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                                                                    Exhibit 4(b)





                              AMENDMENT NO. 4 TO
                               CREDIT AGREEMENT


         THIS AMENDMENT NO. 4 TO CREDIT AGREEMENT ("Amendment
No. 4") dated as of September 3O, 1994 by and among Quaker State
Corporation, a Delaware corporation (the "Borrower"), the Banks
party to the Credit Agreement (as hereinafter defined) and PNC
Bank, National Association, a national banking association, as
agent for the banks (the "Agent").

                             W I T N E S S E T H:

         WHEREAS, the parties hereto are parties to that certain
Revolving Credit Agreement, dated as of March 31, 1992, as
amended by Amendment No. 1 ("Amendment No. 1") to Credit
Agreement dated as of September 30, 1992, Amendment No. 2 to
Credit Agreement dated as of August 16, 1993 and Amendment No. 3
to Credit Agreement dated as of August 1, 1994, (as amended, the
"Credit Aqreement"); and

         WHEREAS, the Borrower proposes pursuant to the
Acquisition Documents (as herein defined) (i) to purchase all of
the capital stock of Westland Oil Company, Inc. and the Specialty
Oil Companies and certain related assets for an aggregate
consideration of approximately $130,000,000 consisting of cash,
assumption of indebtedness of the Acquired Companies and shares
of common stock of the Borrower and (ii) to merge the Specialty
Oil Companies into Specialty Oil (as herein defined).

         WHEREAS, the Borrower, the Banks and the Agent hereby
desire to amend the Credit Agreement to permit such transactions
as hereinafter provided.

         NOW, THEREFORE, the parties hereto, in consideration of
their mutual covenants and agreements hereinafter set forth and
intending to be legally bound, hereby covenant and agree as
follows:

         1.  DEFINITIONS.

         Defined terms used herein unless otherwise defined
herein shall have the meanings given to them in the Credit
Agreement.

         2.  AMENDMENT OF CREDIT AGREEMENT.

         The parties hereto do hereby modify and amend the
Credit Agreement as follows:

         A.  Article I, Section 1.01 [Certain Definitions, pp.
1-16] is hereby amended as follows:


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         (i)  Immediately prior to the definition of "Adjusted
Interest Charqes", the following definitions are inserted:

        Acquired Companies shall mean Westland Oil
        Company, Inc. and the Specialty Oil
        Companies.

        Acquisition shall mean the consummation of
        the transactions contemplated by the
        Acquisition Documents.

        Acquisition Documents shall mean the
        Agreement and Plan of Merger dated as of
        August 3, 1994 by and among the Borrower, SO
        Acquisition Corp. and the Specialty Oil
        Companies; the Stock Exchange Agreement dated
        as of August 3, 1994 by and among the
        Borrower and the shareholders of Westland Oil
        Company, Inc., and the Agreement to Buy and
        Sell between Moon Realty and the Borrower,
        the Registration Rights and Transfer
        Agreement dated August 3, 1994 between the
        Borrower and certain shareholders of the
        Borrower, the Assignment of Scrip Dividend
        Note between L. David Myatt and the Borrower;
        the Indemnification Agreements among the
        Borrower and certain shareholders of the
        Acquired Companies, the Employment Agreements
        between the Borrower and certain employees of
        the Acquired Companies, and any other
        instruments, certificates or documents
        delivered in connection therewith.

         (ii)  Immediately prior to the definition of "month",
the following definition is inserted:

        Moon Realty shall mean a partnership in which
        certain shareholders of the Acquired
        Companies are partners.

         (iii)  The definition of "Permitted Liens" is hereby
amended by deleting the "." at the end of such definition and
inserting in lieu thereof the following:
        
         ;

         (xi)  Liens on the assets of the Acquired
         Companies or Specialty Oil securing
         Indebtedness of such Subsidiaries to any
         person or persons as in effect upon the
         consummation of the Acquisition.

         (iv)  Immediately prior to the definition of
"Subsidiary", the following definitions are inserted:


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        Specialty Oil shall mean Specialty Oil
        Company, Inc., formerly named SO Acquisiton
        Corp., a wholly owned subsidiary of the
        Borrower and successor by merger to the
        Specialty Oil Companies.

        Specialty Oil Companies shall mean Specialty
        Oil Company, Inc.-I, Specialty Oil Company,
        Inc.-II, Specialty Oil Company, Inc.-III and
        Specialty Oil Company, Inc.-IV.


         B. Article II, Section 2.03 [Commitment Fees, p.17]
is hereby amended by deleting from the eighth line thereof "one-
fourth percent (1/4%)" and inserting in lieu thereof "three
sixteenths percent (3/16%)."

         C. Article VII, Section 7.02(1)  [Negative Covenants -
Guaranties, p. 10 of Amendment No. 1] is hereby amended and
restated to read as follows:

        (1) Guaranties. The Borrower will not, and
        will not permit any Subsidiary to, become or
        be liable in respect of any Guaranty except:

            (i) Guaranties by the Borrower or
            any Subsidiary which are limited in
            amount to a stated maximum dollar
            exposure;

            (ii) Guaranties by the Borrower of
            guaranty obligations of certain
            shareholders of the Acquired
            Companies, as set forth in the
            Acquisition Documents;

            (iii) Guaranties by the Acquired
            Companies and Specialty Oil of
            obligations of Moon Realty as in
            effect upon the consummation of the
            Acquisition, as set forth in the
            Commercial Guaranty Agreements each
            dated March 19, 1990, among the
            Acquired Companies and Moon Realty;
            or

            (iv) Guaranties of obligations of
            any Subsidiary incurred in
            compliance with the provisions of
            this Agreement.

         D. Article VII, Section 7.02(m) [Negative Covenants -
Limitations Affecting Subsidiaries, p. 10-11 of Amendment No. 1],
is hereby amended by deleting the "." at the end of such section
and inserting in lieu thereof the following:


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         ;

        (D) any restriction contained in any
        agreement or instrument applicable to the
        Acquired Companies or Specialty Oil in effect
        at the time of the Acquisition, including any
        restriction contained in the Acquisition
        Documents.

         3. CONDITIONS OF EFFECTIVENESS. The effectiveness of
this Amendment No. 4 is expressly conditioned upon: (i) the
Agent's receipt for the benefit of each Bank of a written opinion
of counsel for the Borrower, satisfactory to the Agent, dated a
date satisfactory to the Agent; (ii) the Agent's receipt of
counterparts of this Amendment No. 4 duly executed by the
Borrower and each of the Banks; (iii) the Agent's receipt of a
certificate signed by the Secretary or Assistant Secretary of the
Borrower, dated as of a date satisfactory to the Agent,
certifying as to all action taken by the Borrower to authorize
the execution, delivery and performance of this Amendment No. 4;
and (iv) the consummation of the Acquisition on or before
October 31, 1994. If all of the conditions to the effectiveness
of this Amendment No. 4 are not met on or before October 31,
1994, this Amendment No. 4 shall become null and void and of no
force or effect.

         4. DELIVERY OF PRO FORMA. The Borrower hereby
covenants to deliver to the Agent and the Banks, as soon as
available and in any event no later than the date on which the
Borrower files its pro forma balance sheet with the Securities
and Exchange Commission required in connection with reporting the
Acquisition on Form 8-K, an unaudited consolidated balance sheet
of the Borrower and its Subsidiaries as of the date of the
Acquisition after giving effect to the Acquisition. The Banks
hereby waive compliance with Section 7.03(a) of the Credit
Agreement to the extent such Section would otherwise require the
Borrower to deliver the pro forma balance sheet described in the
foregoing sentence at an earlier time than described in the
foregoing sentence.

         5. MISCELLANEOUS. 

              A. Except as expressly modified and amended by
this Amendment No. 4, the Credit Agreement and the other Loan
Documents are hereby ratified and confirmed and shall remain in
full force and effect.

              B. The Borrower affirms the representations and
warranties made by it to the Banks in Article V of the Credit
Agreement as of the date hereof (except representations and
warranties which expressly relate to an earlier date or time,
which representations and warranties shall be true and correct on
and as of the specific dates or times referred to therein). The
Borrower represents and warrants to the Banks that no Event of
Default or Potential Default shall have occurred and be

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continuing, and the execution and performance of this Amendment
No. 4 shall not give rise to an Event of Default or Potential
Default.

              C. This Amendment No. 4 may be executed by
different parties hereto in any number of separate counterparts,
each of which, when so executed and delivered shall be an
original and all of such counterparts shall together constitute
one and the same instrument.

              D. This Amendment No. 4 shall be governed by and
construed in accordance with the internal laws of the
Commonwealth of Pennsylvania.


                    INTENTIONALLY BLANK





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          IN WITNESS WHEREOF, the parties hereto by their
officers duly authorized, have executed this Amendment No. 4 as
of the date and year first above written.

                                      BORROWER:

                                      QUAKER STATE CORPORATION


                                      By: R. SCOTT KEEFER
                                         ----------------------------
                                         R. Scott Keefer
                                         Vice President, Finance and
                                         Chief Financial Officer


                                      BANKS:

                                      PNC BANK, NATIONAL ASSOCIATION
                                      Individually and as Agent


                                      By:
                                         ----------------------------
                                         Judith P. Hannon
                                         Vice President


                                      MORGAN GUARANTY TRUST COMPANY
                                      OF NEW YORK


                                      By:
                                         ----------------------------
                                         James Finch
                                         Vice President


                                      INTEGRA NATIONAL BANK/NORTH


                                      By:
                                         ----------------------------
                                         Edward R. Say
                                         Vice President




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         IN WITNESS WHEREOF, the parties hereto by their
officers duly authorized, have executed this Amendment No. 4 as
of the date and year first above written.

                                      BORROWER:

                                      QUAKER STATE CORPORATION


                                      By:
                                         ----------------------------
                                         R. Scott Keefer
                                         Vice President, Finance and
                                         Chief Financial Officer


                                      BANKS:

                                      PNC BANK, NATIONAL ASSOCIATION
                                      Individually and as Agent


                                      By: JUDITH P. HANNON
                                         ----------------------------
                                         Judith P. Hannon
                                         Vice President


                                      MORGAN GUARANTY TRUST COMPANY
                                      OF NEW YORK


                                      By:
                                         ----------------------------
                                         James Finch
                                         Vice President


                                      INTEGRA NATIONAL BANK/NORTH


                                      By:
                                         ----------------------------
                                         Edward R. Say
                                         Vice President




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         IN WITNESS WHEREOF, the parties hereto by their
officers duly authorized, have executed this Amendment No. 4 as
of the date and year first above written.

                                      BORROWER:

                                      QUAKER STATE CORPORATION


                                      By:
                                         ----------------------------
                                         R. Scott Keefer
                                         Vice President, Finance and
                                         Chief Financial Officer


                                      BANKS:

                                      PNC BANK, NATIONAL ASSOCIATION
                                      Individually and as Agent


                                      By:
                                         ----------------------------
                                         Judith P. Hannon
                                         Vice President


                                      MORGAN GUARANTY TRUST COMPANY
                                      OF NEW YORK


                                      By: ROBERT BOTTAMEDI
                                         ----------------------------
                                         Robert Bottamedi
                                         Vice President


                                      INTEGRA NATIONAL BANK/NORTH


                                      By:
                                         ----------------------------
                                         Edward R. Say
                                         Vice President




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         IN WITNESS WHEREOF, the parties hereto by their
officers duly authorized, have executed this Amendment No. 4 as
of the date and year first above written.

                                      BORROWER:

                                      QUAKER STATE CORPORATION


                                      By:
                                         ----------------------------
                                         R. Scott Keefer
                                         Vice President, Finance and
                                         Chief Financial Officer


                                      BANKS:

                                      PNC BANK, NATIONAL ASSOCIATION
                                      Individually and as Agent


                                      By:
                                         ----------------------------
                                         Judith P. Hannon
                                         Vice President


                                      MORGAN GUARANTY TRUST COMPANY
                                      OF NEW YORK


                                      By:
                                         ----------------------------
                                         James Finch
                                         Vice President


                                      INTEGRA NATIONAL BANK/NORTH


                                      By: EDWARD R. SAY
                                         ----------------------------
                                         Edward R. Say
                                         Vice President




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