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                                                                     Exhibit 5.1

                      [Vinson & Elkins L.L.P. Letterhead]

                                  May 20, 1998



Quaker State Corporation
225 East John Carpenter Freeway
Irving, Texas  75062

              Re:    Registration Statement on Form S-8 for the Non-Employee
                     Directors Restricted Stock

Gentlemen:

       We have acted as counsel to Quaker State Corporation, a Delaware
corporation (the "Corporation"), in connection with the above-captioned
registration statement (the "Registration Statement") relating to the 65,383
shares (the "Plan Shares") of Capital Stock, par value $1.00 per share, of the
Corporation that may be issued under its Non-Employee Director Restricted Share
Agreements (the "Plan").  Either authorized but unissued or treasury shares of
Capital Stock may be used under the Plan.  In rendering our opinion below, we
have assumed that only authorized but unissued shares will be issued under the
Plan.

       In connection with this opinion, we have examined, among other things:

       1.     resolutions adopted by the Corporation's Board of Directors on
February 4, 1998;

       2.     the Certificate of Incorporation of the Corporation as in effect
at all times since the last amendment to the Certificate of Incorporation
effective June 13, 1997;

       3.     the Bylaws of the Corporation, as amended and restated effective
on May 15, 1998;

       4.     the Plan, as approved by the Corporation's stockholders at the
Corporation's Annual Meeting of Stockholders held on May 15, 1998;

       5.     a copy of the Report of Inspectors of Election, indicating that
the Plan was approved by the Corporation's stockholders at the Corporation's
Annual Meeting of Stockholders held on May 15, 1998; and
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Quaker State Corporation
May 20, 1998
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       6.     the form of Non-Employee Director Restricted Share Agreement to
be executed by the non-employee directors and the Company.

       As to matters of fact relevant to the opinions expressed herein, and as
to factual matters arising in connection with our examination of corporate
documents, records and other documents and writings, we have relied upon
certificates and other communications of corporate officers of the Corporation,
without further investigation as to the facts set forth therein.

       Based on the foregoing and upon an examination of such other documents,
corporate proceedings, statutes, decisions, certificates of public officials,
and questions of law as we considered necessary in order to enable us to
furnish this opinion, we advise you that in our opinion the Plan Shares have
been duly authorized, and upon issuance in accordance with the provisions of
the Plan, will be validly issued, fully paid and nonassessable.

       The opinion expressed above is subject to the following assumptions,
exceptions and qualifications:

       a.     We have assumed that (i) all information in all documents
reviewed by us is true and correct, (ii) all signatures on all documents
reviewed by us are genuine, (iii) all documents submitted to us as originals
are true and complete, (iv) all documents submitted to us as copies are true
and complete copies of the originals thereof, (v) each person signing any
document reviewed by us in any representative capacity had proper authority to
do so, and (vi) each natural person signing any document reviewed by us had the
legal capacity to do so.

       b.     We are admitted to practice law in the State of Texas.  The
foregoing opinion is limited to the General Corporation Law of the State of
Delaware and the federal laws of the United States of America.

       We express no opinion as to any matter other than as expressly set forth
above, and no opinion on any other matter may be inferred or implied herefrom.

       We hereby consent to the filing of this opinion  as an Exhibit to the
Registration Statement and to the use of our name under the caption "Legal
Opinion" in the Section 10(a) prospectus used in connection with the Plan and
the Registration Statement.  In giving this consent, however, we do not hereby
admit that we are within the category of persons whose consent is required
under Section 7 of the Securities Act of 1933 and the rules and regulations of
the Securities and Exchange Commission promulgated thereunder.


                                           Very truly yours,


                                           /s/  Vinson & Elkins L.L.P.