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                                                                    EXHIBIT 99.4


March 15, 2001

Pennzoil-Quaker State Company


Re: Annual Report on Form 10-K for the year ended December 31, 2000

    Gentlemen:

    This letter is written to meet the requirements of Regulation S-K calling
    for a letter from a registrant's independent accountants whenever there has
    been a change in accounting principle or practice.

    In 2000, the Company changed from the last-in, first-out (LIFO) method of
    accounting for certain inventories to the average cost method. Consequently,
    all of the Company's inventories are stated at average cost. According to
    the management of the Company, this change was made to more accurately
    measure operating results for its continuing operations by recognizing raw
    material price fluctuations as they occur on a moving average basis, reduce
    the cost of sales volatility that would be caused by pending inventory
    liquidations and adjust inventory balances to amounts that more closely
    reflect the inventories' current cost. In addition, the average cost method
    is the predominant method used in the consumer products industry.

    A complete coordinated set of financial and reporting standards for
    determining the preferability of accounting principles among acceptable
    alternative principles has not been established by the accounting
    profession. Thus, we cannot make an objective determination of whether the
    change in accounting described in the preceding paragraph is to a preferable
    method. However, we have reviewed the pertinent factors, including those
    related to financial reporting, in this particular case on a subjective
    basis, and our opinion stated below is based on our determination made in
    this manner.

    We are of the opinion that the Company's change in method of accounting is
    to an acceptable alternative method of accounting, which, based upon the
    reasons stated for the change and our discussions with you, is also
    preferable under the circumstances in this particular case. In arriving at
    this opinion, we have relied on the business judgment and business planning
    of your management.


Very truly yours,

ARTHUR ANDERSEN LLP