Document:

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                                                                    Exhibit 4.16

                             CERTIFICATE OF TRUST
                                      OF
                                  HFI TRUST I

        THIS CERTIFICATE OF TRUST of HFI Trust I (the "Trust"), dated as of
March 27, 2001, is being duly executed and filed by the undersigned, as
trustees, with the Secretary of State of the State of Delaware to form a
business trust under the Delaware Business Trust Act (12 Del. Code 3801 et
seq.).

        1. Name. The name of the business trust being formed hereby is "HFI
Trust I."

        2. Delaware Trustee. The name and business address of the trustee of the
Trust with a principal place of business in the State of Delaware are The Bank
of New York (Delaware), White Clay Center, Route 273, Newark, Delaware 19711.

        3. Effective Date. This Certificate of Trust shall be effective at the
time of its filing with the Secretary of State of the State of Delaware.

        4. Counterparts. This Certificate of Trust may be executed in one or
more counterparts.

                          [signature page to follow]

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        IN WITNESS WHEREOF, the undersigned, being all of the trustees of the
Trust at the time of filing of this Certificate of Trust, have executed this
Certificate of Trust as of the date first above written.

                                THE BANK OF NEW YORK (DELAWARE),
                                as Delaware Trustee

                                By:   /s/ William T. Lewis
                                   ---------------------------------
                                  Name:   William T. Lewis
                                 Title:   SVP

                                BNY MIDWEST TRUST COMPANY,
                                as Property Trustee

                                By:   /s/ D.G. Donovan
                                   ---------------------------------
                                  Name:   D.G. Donovan
                                 Title:   Assistant Vice President

                                KURT ROEMER,
                                as Regular Trustee

                                     /s/ Kurt Roemer
                                ------------------------------------

                                       2<PAGE>

                                                                    EXHIBIT 10.8

                                  PREMCOR INC.

                            LONG TERM INCENTIVE PLAN

                                                                    JANUARY 2001
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                                  Premcor Inc.
                            Long Term Incentive Plan

                               TABLE OF CONTENTS
                               -----------------

                                                                            PAGE
                                                                            ----

1. Establishment and Purpose................................................   1
   1.1  Establishment of the Plan...........................................   1
   1.2  Purpose.............................................................   1

2. Definitions..............................................................   1

3. Administration...........................................................   3
   3.1  The Board...........................................................   3
   3.2  Authority of the Board..............................................   3
   3.3  Amendment, Modification, and Termination............................   4
   3.4  Decisions Binding...................................................   4

4. Eligibility and Participation............................................   4
   4.1  Eligibility.........................................................   4
   4.2  Actual Participation................................................   4
   4.3  Timing of Participation.............................................   4

5. Incentive Award Opportunity..............................................   5
   5.1  Establishment of the Targets........................................   5
   5.2  Establishment of Performance Measures...............................   5
   5.3  Pay-out of Awards and Deferrals.....................................   6
   5.4  Award Agreement.....................................................   6

6. Termination of Employment and Change in Control..........................   6
   6.1  Termination of Employment - Death, Disability, Normal Retirement,
        or Involuntarily....................................................   6
   6.2  Termination of Employment - Cause or Voluntarily....................   7
   6.3  Change in Control...................................................   7

7. Beneficiary..............................................................   7
   7.1  Designation of Beneficiary..........................................   7
   7.2  Death of Beneficiary................................................   7
   7.3  Ineffective Designation.............................................   7

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8. Rights of Participants..................................................   8
   8.1 Employment..........................................................   8
   8.2  Participation......................................................   8
   8.3  Nontransferability.................................................   8
   8.4  Unsecured Interest.................................................   8

9. Miscellaneous Provisions................................................   8
   9.1  Costs of the Plan..................................................   8
   9.2  Tax Withholding....................................................   8
   9.3  Special Compensation...............................................   8
   9.4  Successors.........................................................   9
   9.5  Severability.......................................................   9
   9.6  Gender and Number..................................................   9
   9.7  Governing Law......................................................   9

                                       ii

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                                  Premcor Inc.
                            Long Term Incentive Plan

1.   Establishment and Purpose.

     1.1  Establishment of the Plan.

     The Company hereby establishes a long-term management incentive
compensation arrangement to be known as the Plan, as set forth in this document.

     Upon approval by the Board of Directors, the Plan shall become effective as
of January 1, 2001.  The Plan shall remain in effect until terminated by the
Board of Directors.

     1.2  Purpose.

     The primary purpose of the Plan is to provide a significant incentive for
Key Management Employees to focus their activities toward the achievement of
specific long-term Company financial objectives.  The Plan also has a purpose of
establishing an incentive for Participants to maintain their employment with the
Company.

2.   Definitions.

     Whenever used in this Plan, the following terms shall have the meanings set
forth below:

     a.   "Award Agreement" means an agreement between the Company and a
          Participant that sets forth the terms and provisions applicable to a
          Performance Period, as further provided in Section 5.4.

     b.   "Board of Directors" or "Board" means the Board of Directors of the
          Company.

     c.   "Cause" means (i) the willful and continuous failure by a Participant
          to substantially perform Participant's duties with the Company (other
          than any such failure resulting from Participant's incapacity due to
          physical or mental illness) after a written demand for substantial
          performance is delivered to Participant by the Board which
          specifically identifies the manner in which the Board believes that
          the Participant has not substantially performed Participant's duties,
          (ii) gross misconduct or gross negligence by the Participant or (iii)
          the Participant's conviction of or the entering of a plea of guilty or
          nolo contendere to the commission of a felony.

     d.   "Change in Control" means:

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               (i) the consummation of (A) any consolidation, reorganization,
          merger or similar transaction involving the Company, other than a
          consolidation, reorganization, merger or similar transaction in which
          the shareholders immediately prior to such transaction own more than
          50% of the combined voting power of the voting securities of the
          surviving corporation, (B) any sale, lease, exchange or other transfer
          (in one transaction or a series of related transactions) of all or
          substantially all of the assets of the Company, or (C) the liquidation
          or dissolution of the Company

               (ii) when any Person (as defined in Sections 13(d) and 14(d)(2)
          of the Securities Exchange Act of 1934), other than an employee
          benefit plan or trust maintained by the Company or any of its
          Subsidiaries, becomes the "beneficial owner" (as defined in Rule 13d-3
          under the Securities Exchange Act of 1934), directly or indirectly, of
          more than 25% of the voting power of the Company outstanding at the
          time (in one or more related or unrelated transactions)(a "Significant
          Interest"), but only if at such time such interest is greater than
          Blackstone Capital Partners III Merchant Banking Fund L.P. and its
          affiliate's beneficial ownership (as defined in Rule 13d-3 under the
          Securities Exchange Act of 1934) of the voting power of the Company
          ("Blackstone's Interest")

               (iii) when, during any period of 24 months or less, the
          individuals who constituted the Board at the beginning of such period
          shall cease for any reason to constitute at least a majority thereof,
          unless the election or the nomination for election by the Company's
          shareholders, as the case may be, of each new director during such
          period was approved by a vote of at least two-thirds of the directors
          then still in office who were directors at the beginning of such
          period.

     e.   "Company" means Premcor Inc. and its successors, as further provided
          in Section 9.4.

     f.   "Director" means an individual who is a member of the Board of
          Directors.

     g.   "Disability" means a permanent and total disability which prohibits a
          Participant from performing his or her employment duties and
          obligations, within the meaning of Internal Revenue Code Section
          22(e)(3), or any successor provision, as determined by the Board in
          good faith, upon receipt of, and in reliance on, sufficient competent
          medical advice from one or more individuals, selected by the Board,
          who are qualified to give professional medical advice.

     h.   "Effective Date" means the date this Plan becomes effective, as set
          forth in Section 1.1.

     i.   "Fiscal Year" means the Company's fiscal year consisting of the twelve
          (12) calendar months beginning each January 1 and ending December 31.

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     j.   "Key Management Employee" means a management employee of the Company
          or a subsidiary thereof that contributes directly to the long-term
          success of the Company and/or its subsidiaries and divisions, as
          further provided in Section 4.

     k.   "Normal Retirement" means termination of employment on or after
          attainment of age sixty-five (65).

     l.   "Participant" means an employee of the Company or a subsidiary thereof
          who has (i) been nominated for eligibility by the Chief Executive
          Officer, (ii) been approved by the Board as being a Key Management
          Employee and (iii) executed an Award Agreement that specifies the
          details of the employee's participation for a specific Performance
          Period.

     m.   "Performance Measure(s)" means one or more Company financial goals
          established for each Performance Period by the Board, upon
          recommendation by the Chief Executive Officer, used to determine the
          size of award payments hereunder to Participants, as further described
          in Section 5.

     n.   "Performance Period" means a period of three (3) consecutive Fiscal
          Years of the Company, beginning with the first day of a specified
          Fiscal Year, during which the degree of achievement of the Performance
          Measures shall determine the size of award payments hereunder to
          Participants, as further described in Section 5.2. At the discretion
          of the Board, new Performance Periods may overlap and can commence as
          frequently as on an annual basis.

3.   Administration

     3.1  The Board.

     This Plan shall be administered by the Board, the Compensation Committee or
any other committee consisting of not less than two (2) Directors who shall be
appointed from time to time by, and shall serve at the discretion of, the Board.

     3.2  Authority of the Board.

     The Board shall have full power to select and approve Participants from
among those nominated by the Chief Executive Officer ("CEO"); to determine the
frequency and size of the incentive award opportunity (which need not be the
same for each Participant); to determine the terms and conditions of each
individual's participation in a manner consistent with the provisions of the
Plan; to establish Performance Measures and the weight of those measures by
operating unit (if applicable); to establish specific definitions for the
Performance Measures, and to ensure that these definitions will be applied on a
consistent basis from year to year; to set forth guidelines governing the
minimum, target, and maximum awards that may be earned by Participants with
respect to various levels of achievement of the Performance Measures during the
Performance Period, subject to the terms of Section 5; to revise the Performance
Measures during a Performance Period only to the extent necessary in equity to
preserve the integrity of the

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measures; to construe and interpret the Plan and any agreement or instrument
entered into under the Plan; to establish, amend, rescind, or waive rules and
regulations for the Plan's administration; to delegate administrative duties
pertaining to recordkeeping, and to rely on outside counsel, independent
accountants, or other consultants to render advice and/or assistance in
fulfilling administrative duties; and, subject to the provisions in Section 3.3,
to amend, modify or terminate the Plan.

     The Board shall have the full discretionary power to make any and all
determinations which may be necessary or advisable for the administration of the
Plan, to the extent consistent with the provisions of the Plan.

     3.3  Amendment, Modification, and Termination.

     At any time, and from time to time, the Board may amend, modify or
terminate the Plan.  However, no amendment, modification or termination shall
adversely affect the rights and/or interest of a Participant pertaining to any
Performance Period in progress at the time of the amendment, modification or
termination.

     3.4  Decisions Binding.

     All determinations and decisions made by the Board pursuant to the
provisions of the Plan shall be final, conclusive and binding on all persons,
including the Company, its owners, subsidiaries, employees, Participants, and
their estates and beneficiaries.

4.   Eligibility and Participation.

     4.1  Eligibility.

     Eligibility for participation in the Plan shall be limited to those
employees who have been designated by the CEO of the Company as being Key
Management Employees.

     4.2  Actual Participation.

     Subject to the provisions of the Plan, prior to the beginning of each
Performance Period (or as close thereto as administratively possible), the Board
will identify which, if any, Key Management Employees (as nominated by the CEO
of the Company) shall participate in the Performance Period about to begin.

     Prior to the beginning of each Performance Period (or as close thereto as
administratively possible), and as soon as practicable following the approval by
the Board, each Participant shall execute an Award Agreement with the Company
(as provided in Section 5.4), which shall describe the terms and conditions of
each individual's participation in the corresponding Performance Period.

     4.3  Timing of Participation.

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     Participation in the Plan shall begin on the first day of each Performance
Period. However, the Board, in its sole discretion, may allow an individual who
becomes eligible during a Performance Period to participate in the Plan.  In
such case, the Participant's degree of participation for such Performance Period
shall be determined by the Board at its discretion; however, in such case,
participation generally shall be prorated, based upon the number of full months
of actual participation during such Performance Period.

5.   Incentive Award Opportunity.

     5.1  Establishment of the Targets.

     Prior to the beginning of each Performance Period (or as close thereto as
administratively possible), the Board shall establish a target award incentive
opportunity for each Participant (which may differ for each Participant), as
recommended to the Board by the CEO of the Company.  Each target award amount
shall represent the amount of cash or common stock of the Company (or any
successor thereof) that can be earned by the Participant at the end of the
Performance Period, based upon the achievement of one hundred percent (100%) of
the pre-established Performance Measures.

     Prior to the beginning of each Performance Period (or as close thereto as
administratively possible), the Board also shall establish minimum and maximum
award incentive opportunities for each Participant for achievement of the
Performance Measures at a level either less than or greater than one hundred
percent (100%).  Performance at a level less than the minimum shall result in no
award.

     The target, minimum and maximum award incentive opportunities shall be
communicated to each Participant within the respective Award Agreement, as
executed at the beginning of each Performance Period pursuant to Section 5.4 (or
as close thereto as administratively possible).

     5.2  Establishment of Performance Measures.

     Prior to the beginning of each Performance Period, the Board shall
establish one or more Performance Measures, as recommended to the Board by the
CEO.  The Performance Measures shall be based upon Company financial goals and
shall be weighted as determined by the Board.  Performance measures will reflect
key strategic goals or critical operating objectives over a three-year time
frame.

     The level of achievement of the Performance Measures at the end of the
respective Performance Period shall determine the percentage, if any, of the
target award to be paid.

     Further, at the same time Performance Measures are set, the Board may
establish a "hurdle" rate of annual growth in sales, profits, or return on
equity, or other financial measure.  Unless this hurdle rate is achieved by the
end of the respective Performance Period, no award

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payment will be made, regardless of the level of achievement of the pre-
established Performance Measures.

     5.3  Pay-out of Awards and Deferrals.

     Participants that are in the employ of the Company on the last day of a
Performance Period shall receive a pay-out for that Performance Period, based
upon the pre-established minimum, target or maximum incentive award
opportunities (as provided in Section 5.1), in relation to the level of
achievement of pre-established Performance Measures (as provided in Section
5.2).

     When earned, pay-out shall be made in a cash lump sum or if the Board so
elects, in shares of common stock of the Company (or any successor thereof) as
soon as practicable following the end of the corresponding Performance Period,
but in no event beyond the March 15 of the calendar year following the calendar
year in which the Performance Period ends.

     5.4  Award Agreement.

     Prior to the beginning of each Performance Period (or as soon thereafter as
administratively possible), the Company shall execute an Award Agreement with
each Participant.  The Agreement shall describe the terms and conditions of each
individual's participation in the Plan for the relevant Performance Period and
shall include, among other information, each Participant's minimum, target and
maximum incentive award opportunities, along with the corresponding Performance
Measures to be achieved.  The included terms and conditions need not be the same
for each Participant, nor for each Performance Period.

6.   Termination of Employment and Change in Control.

     6.1  Termination of Employment - Death, Disability, Normal Retirement, or
Involuntarily.

     In the event a Participant's employment is terminated during a Performance
Period (i) by reason of death, Disability or Normal Retirement or (ii)
involuntarily by the Company other than for Cause as described in Section 6.2,
the Participant shall receive a prorated target incentive award for all
outstanding awards.  The amount of the award shall be determined be multiplying
the Participant's pre-established target award amount for each Performance
Period then in progress by a fraction, the numerator of which is the number of
full months of participation during the Performance Period(s) through the date
of employment termination, and the denominator of which is thirty-six (36).  In
the event of death or Disability, the Participant's date of employment
termination shall be deemed to be the first day of the calendar month following
the month in which the Participant dies or incurs a Disability.

     This prorated award shall be paid at the end of the Performance Period in
accordance with the provisions of Section 5.3 and based on the Performances
Measures achieved as of the end of the Performance Period.

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     6.2  Termination of Employment - Cause or Voluntarily.

     In the event a Participant's employment is terminated for Cause or the
Participant voluntarily terminates employment, all of the Participant's awards
then outstanding shall immediately be forfeited with no pay-out, along with all
associated rights thereto. For purposes of this forfeiture, Cause shall be
determined by the Board in good faith.

     6.3  Change in Control.

     Notwithstanding any provision in this Plan to the contrary, the Board may
include provisions in an Award Agreement to address the effect of a Change in
Control on the payment and value of a Participant's incentive opportunity.

7.   Beneficiary.

     7.1  Designation of Beneficiary.

     Each Participant shall be entitled to designate a beneficiary or
beneficiaries who, following the Participant's death, will be entitled to
receive any amounts that otherwise would have been paid to the Participant under
the Plan.  Each designation shall be effective as of the date delivered by a
Participant to the Vice President of Human Resources of the Company.  The
Participant may change his or her beneficiary designation at any time, on such
form as prescribed by the Board.

     The payment of any amounts owing to a deceased Participant pursuant to his
or her outstanding awards hereunder shall be in accordance with the last
unrevoked written designation of beneficiary that has been signed and delivered
by the Participant to the Vice President of Human Resources prior to the
Participant's death.

     7.2  Death of Beneficiary.

     In the event that a designated beneficiary, as provided in Section 7.1,
predeceases the Participant, the share which such beneficiary would have
received shall be payable equally first to the remaining primary beneficiaries,
or if no primary beneficiaries survive the Participant, to the remaining
secondary beneficiaries.  In the event that all primary and secondary
beneficiaries predecease the Participant, the amounts shall be paid to the
Participant's estate.  In such an event, the term "beneficiary" shall include
the Participant's estate.

     7.3  Ineffective Designation.

     In the event the Participant does not designate a beneficiary, or if for
any reason such designation is ineffective, in whole or in part, the amounts
that otherwise would have been paid to the Participant shall be paid to the
Participant's estate, and in such event, the term "beneficiary" shall include
the Participant's estate.

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8.   Rights of Participants.

     8.1 Employment.

     Nothing in the Plan shall interfere with or limit in any way the right of
the Company to terminate any Participant's employment at any time, nor confer
upon any Participant any right to continue in the employ of the Company.

     8.2  Participation.

     No Participant or other employee shall at any time have a right to be
selected for participation in the Plan for any Performance Period, despite
having been selected for participation in a previous Performance Period.

     8.3  Nontransferability.

     No right or interest granted to a Participant under the Plan may be sold,
transferred, pledged, assigned, or otherwise alienated or hypothecated, other
than by will or by the laws of descent and distribution.

     8.4  Unsecured Interest.

     No Participant or beneficiary shall have any interest whatsoever in any
specific asset of the Company.  To the extent that any person acquires a right
to receive payment under this Plan, such right shall be no greater than the
right of any unsecured general creditor of the Company.

9.   Miscellaneous Provisions.

     9.1  Costs of the Plan.

     All costs of the Plan, including but not limited to pay-out of awards and
administrative expenses, shall be incurred by the Company out of the Company's
general assets.  Although not prohibited from doing so, the Company is not
required in any way to segregate assets in any manner or to specifically fund
the benefits provided under the Plan.

     9.2  Tax Withholding.

     The Company shall have the right to require a Participant to remit to the
Company an amount sufficient to satisfy federal, state, and local withholding
tax requirements, or to deduct from any or all payments under this Plan amounts
sufficient to satisfy all required withholding tax requirements.

     9.3  Special Compensation.

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     To the extent permitted by law, amounts paid under this Plan shall not be
considered to be compensation for purposes of any benefit plan or program
maintained by the Company.

     9.4  Successors.

     All obligations of the Company under the Plan with respect to pay-out of
awards, and the corresponding rights granted hereunder, shall be binding on any
successor to the Company, whether the existence of such successor is the result
of a direct or indirect purchase, merger, consolidation, or other acquisition of
all or substantially all of the business and/or assets of the Company.

     9.5  Severability.

     In the event that any provision of the Plan shall be held illegal or
invalid for any reason, the illegality or invalidity shall not affect the
remaining parts of the Plan, and the Plan shall be construed and enforced as if
the illegal or invalid provision had not been included.

     9.6  Gender and Number.

     Except where otherwise indicated by the context, any masculine term used
herein also shall include the feminine, the plural shall include the singular
and the singular shall include the plural.

     9.7  Governing Law.

     To the extent not preempted by federal law, the Plan, and all agreements
hereunder, shall be construed in accordance with and governed by the laws of the
State of Delaware.

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