<PAGE>
                                                                   EXHIBIT 10.4


                                                                  March 5, 2002



Mr. James J. Postl
President and Chief Executive Officer
Pennzoil-Quaker State Company
P. O. Box 2967
Houston, Texas  77252-2967

Dear Jim:

                  In order to take advantage of your substantial expertise, we
propose the following Agreement to be effective as of March 18, 2002,
concerning the provision by you of consulting services to Pennzoil-Quaker State
Company for the three-year period commencing on the date of termination of your
employment with Pennzoil-Quaker State Company (the "Consulting Term").

                  In consideration of the mutual promises and understanding
contained in this Agreement, you and Pennzoil-Quaker State Company agree as
follows:

         1.       You will perform consulting and advisory services on behalf
                  of Pennzoil-Quaker State Company. Such services shall be
                  performed at the request of the Board of Directors of
                  Pennzoil-Quaker State Company, and in connection with your
                  consulting and advisory duties, you will report to the Board
                  of Directors of Pennzoil-Quaker State Company.

         2.       Your services will be rendered primarily in the
                  Pennzoil-Quaker State Company offices in Houston, Texas, and
                  you may travel from time to time upon request by
                  Pennzoil-Quaker State Company.

         3.       In the performance of your services hereunder, the hours you
                  are scheduled to work on any given day will be by mutual
                  agreement with the Board of Directors of Pennzoil-Quaker
                  State Company and Pennzoil-Quaker State Company will rely
                  upon you to accommodate such number of hours as is reasonably
                  necessary to fulfill the spirit and purpose of this
                  Agreement.

         4.       Office and secretarial support will be furnished in Houston
                  as described in Exhibit A to this Agreement. Pennzoil-Quaker
                  State Company cars and aircraft may be utilized as described
                  in Exhibit A to this Agreement.

         5.       During the term of this Agreement, you will not, without the
                  prior written consent of Pennzoil-Quaker State Company,
                  engage directly or indirectly in any business or endeavor
                  (financially as an individual, investor or lenders or as an
                  employee, director, officer, partner, independent contractor,
                  consultant or owner or in any other capacity calling for the
                  rendition of personal services or acts of management,
                  operation or control) which is in competition or inconsistent
                  with, or adverse to or opposed to, the interests of
                  Pennzoil-Quaker State Company. You should contact the Chief
                  Executive Officer of Pennzoil-Quaker State
<PAGE>
                  Company  to request such written consent prior to determining
                  it is appropriate to engage in any particular business or
                  endeavor. Notwithstanding the above, you are not prohibited
                  from investing or trading on your own behalf in publicly
                  traded securities of other companies.

         6.       During the Consulting Term, Pennzoil-Quaker State Company
                  will pay you at the annual rate of $500,000, but in equal
                  monthly amounts of $41,666.66 (except that the last payment
                  shall be $41,666.90) on the first day of the month,
                  commencing upon the date of your termination of employment
                  with Pennzoil-Quaker State Company and continuing each month
                  thereafter with the last payment payable on the first day of
                  the month during which the Consulting Term ends. In addition,
                  Pennzoil-Quaker State Company will reimburse you for all
                  reasonable and necessary travel expenses incurred in
                  performing services under this Agreement as described in
                  Exhibit A to this Agreement. In the event of your death or
                  disability, any amount unpaid under the terms hereof shall be
                  paid to your spouse, if living, or to your estate, on the
                  same terms as provided hereunder for payment, or, in the sole
                  discretion of the Board of Directors of Pennzoil-Quaker State
                  Company, at such earlier date as determined by the Board of
                  Directors of Pennzoil-Quaker State Company.

         7.       Your Tax Protection Agreement dated as of December 30, 1998,
                  will continue in effect.

         8.       Neither you, nor your spouse or other beneficiaries shall
                  have the right to assign any part of your or their rights
                  under this Agreement. This Agreement contains the entire
                  understanding between Pennzoil-Quaker State Company and you
                  regarding this matter and supersedes any prior agreement
                  between the parties.

         9.       This Agreement may not be changed or otherwise amended except
                  by mutual consent evidenced in writing and executed by both
                  parties to this Agreement.

         10.      This Agreement is governed by the laws of the State of Texas.

                                                  Very truly yours,


                                                  /s/ JAMES L. PATE
                                                  -----------------------------
                                                  James L. Pate
                                                  Chairman of the Board
                                                  Pennzoil-Quaker State Company

Accepted and agreed to as of the
5th day of March, 2002.



/s/ JAMES J. POSTL
-----------------------------
James J. Postl


<PAGE>


                   EXHIBIT A TO AGREEMENT DATED MARCH 5, 2002

                              SUPPORT AND EXPENSES


                  The  following are the support and expenses obligations of
Pennzoil-Quaker State Company (the "Company") to James J. Postl ("Mr. Postl")
during the Consulting Term:

         1.       Company cars and aircraft may be utilized under the same
                  terms and conditions as have been applicable during your
                  employment immediately prior to the date of the Agreement,
                  with any personal use of aircraft subject to IRS imputed
                  income requirements.

         2.       Expenses incurred by Mr. Postl in furtherance of the
                  Company's business shall be reimbursed in accordance with
                  customary Company practices and procedures regarding expense
                  reimbursements as in effect immediately prior to the date of
                  this Agreement.

                  The following are the Company's obligations with respect to
retired chief executive officers and will continue throughout Mr. Postl's
retirement and beyond the Consulting Term if upon such retirement Mr. Postl is
entitled to immediate commencement of benefits under the Deferred Compensation
Agreement, dated October 4, 2001, between the Company and Mr. Postl:

         1.       Office space, furniture and equipment appropriate to the
                  status of a retired chief executive officer of a
                  publicly-held company will be provided.

         2.       Company will employ an executive assistant, acceptable to Mr.
                  Postl, who will be an employee of the Company with full
                  participation in the Company's employee benefit plans,
                  programs and practices. The executive assistant will report
                  to Mr. Postl and the duties and compensation of that
                  assistant will be determined by Mr. Postl (within the
                  parameters of overall Company guidelines and policy).

         3.       Mr. Postl and his executive assistant will be provided with
                  parking spaces acceptable to Mr. Postl.

         4.       Full reimbursement for cost of private ground transportation
                  service used in lieu of a Company chauffeured car.