<PAGE>

                                                                  Exhibit 4.13.2


                             DECLARATION OF TRUST
                                      OF
                               SUNOCO CAPITAL II

     THIS DECLARATION OF TRUST OF SUNOCO CAPITAL II is dated as of June 28, 2000
(this "Declaration"), by and among Sunoco, Inc., a Pennsylvania corporation, as
sponsor (the "Sponsor"), Bankers Trust Company, a New York banking corporation,
as trustee (the "Property Trustee"), Bankers Trust (Delaware), a Delaware
banking corporation, as trustee (the "Delaware Trustee"), and Paul A.
Mulholland, as trustee (the "Regular Trustee") (collectively with the Property
Trustee and the Delaware Trustee, the "Trustees"). The Sponsor and the Trustees
hereby agree as follows:

     1.   The trust created hereby shall be known as "Sunoco Capital II" (the
"Trust"), in which name the Trustees or the Sponsor, to the extent provided
herein, may conduct the business of the Trust, make and execute contracts, and
sue and be sued.

     2.   The Sponsor hereby assigns, transfers, conveys and sets over to the
Trust the sum of $10. The Trustees, on behalf of the Trust, hereby acknowledge
receipt of such amount from the Sponsor, which amount shall constitute the
initial trust estate. It is the intention of the parties hereto that the Trust
created hereby constitute a business trust under Chapter 38 of Title 12 of the
Delaware Code, 12 Del. C. (S) 3801, et seq. (the "Business Trust Act"), and
                  -------           -- ---
that this document constitute the governing instrument of the Trust. The
Trustees are hereby authorized and directed to execute and file a certificate of
trust with the Secretary of State of the State of Delaware in such form as the
Trustees may approve.

     3.   The Sponsor and the Trustees will enter into an amended and restated
declaration of trust satisfactory to each such party to provide for the
contemplated operation of the Trust created hereby and the issuance of the
preferred securities and common securities referred to therein. Prior to the
execution and delivery of such amended and restated declaration of trust, the
Trustees shall not have any duty or obligation hereunder or with respect to the
trust estate, except as otherwise contemplated by this Declaration, required by
applicable law or as may be necessary to obtain prior to such execution and
delivery any licenses, consents or approvals required by applicable law or
otherwise. Notwithstanding the foregoing, the Trustees may take all actions
deemed necessary and proper to effect the transactions contemplated herein.

     4.   The Sponsor, as sponsor of the Trust, is hereby authorized (i) to
prepare and file with the Securities and Exchange Commission (the "Commission")
and to execute, in the case of the 1933 Act Registration Statement and 1934 Act
Registration Statement (each as herein defined), on behalf of the Trust, (a) a
Registration Statement (the "1933 Act Registration Statement"), including all
pre-effective and post-effective amendments thereto, relating to the
registration under the Securities Act of 1933, as amended (the "1933 Act"), of
the preferred securities of the Trust, (b) any preliminary prospectus or
prospectus or supplement thereto relating to the preferred securities of the
Trust required to be filed pursuant to the 1933 Act, and (c) a Registration
Statement on Form 8-A or other appropriate form (the "1934 Act Registration
Statement"), including all pre-effective and post-effective amendments thereto,
relating to the registration of the preferred securities of the Trust under the
Securities Exchange Act of 1934, as

                                      -1-
<PAGE>

amended; (ii) if and at such time as determined by the Sponsor, to file with the
New York Stock Exchange, Inc. or any other automated quotation system,
exchange, or over-the-counter market (each, an "Exchange" and collectively, the
"Exchanges"), and execute on behalf of the Trust a listing application and all
other applications, statements, certificates, agreements and other instruments
as shall be necessary or desirable to cause the preferred securities of the
Trust to be listed on any Exchange; (iii) to file and execute on behalf of the
Trust, such applications, reports, surety bonds, irrevocable consents,
appointments of attorney for service of process and other papers and documents
that shall be necessary or desirable to register the preferred securities of the
Trust under the securities or "blue sky" laws of such jurisdictions as the
Sponsor, on behalf of the Trust, may deem necessary or desirable; (iv) to
execute and deliver letters or documents to, or instruments for filing with, a
depository relating to the preferred securities of the Trust; and (v) to
execute, deliver and perform on behalf of the Trust an underwriting agreement
with one or more underwriters relating to the offering of the preferred
securities of the Trust.

     In the event that any filing referred to in this Section 4 is required by
the rules and regulations of the Commission, any Exchange, the National
Association of Securities Dealers ("NASD"), or state securities or "blue sky"
laws to be executed on behalf of the Trust by the Trustees, the Trustees, in
their capacity as trustees of the Trust, are hereby authorized to join in any
such filing and to execute on behalf of the Trust any and all of the foregoing,
it being understood that the Trustees, in their capacity as trustees of the
Trust, shall not be required to join in any such filing or execute on behalf of
the Trust any such document unless required by the rules and regulations of the
Commission, any Exchange, the NASD, or state securities or "blue sky" laws.

     5.   This Declaration may be executed in one or more counterparts.

     6.   The number of trustees of the Trust initially shall be three and
thereafter the number of trustees of the Trust shall be such number as shall be
fixed from time to time by a written instrument signed by the Sponsor which may
increase or decrease the number of trustees of the Trust; provided, however,
that to the extent required by the Business Trust Act, one trustee of the Trust
shall either be a natural person who is a resident of the State of Delaware or,
if not a natural person, an entity which has its principal place of business in
the State of Delaware and otherwise meets the requirements of applicable law.
Subject to the foregoing, the Sponsor is entitled to appoint or remove without
cause any trustee of the Trust at any time.  Any trustee of the Trust may resign
upon thirty days' prior notice to the Sponsor.

     7.   The Sponsor hereby agrees to (i) reimburse the Trustees for all
reasonable expenses (including reasonable fees and expenses of counsel and other
experts) and (ii) indemnify, defend and hold harmless the Trustees and any of
the officers, directors, employees and agents of the Trustees (the "Indemnified
Persons") from and against any and all losses, damages, liabilities, claims,
actions, suits, costs, expenses, disbursements (including the reasonable fees
and expenses of counsel), taxes and penalties of any kind and nature whatsoever
(collectively, "Expenses"), to the extent that such Expenses arise out of or are
imposed upon or asserted at any time against such Indemnified Persons with
respect to the performance of this Declaration, the creation, operation or
termination of the Trust or the transactions contemplated hereby; provided,
however, that the Sponsor shall not be required to indemnify any Indemnified
Person for any

                                      -2-
<PAGE>

Expenses which are a result of the willful misconduct, bad faith or gross
negligence of such Indemnified Person.

     8.   The Trust may be dissolved and terminated before the issuance of the
preferred securities of the Trust at the election of the Sponsor.

     9.   This Declaration shall be governed by, and construed in accordance
with, the laws of the State of Delaware (without regard to conflict of laws
principles).


                           [SIGNATURE PAGE FOLLOWS]

                                      -3-
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Declaration to be
duly executed as of the day and year first above written.

                                    SUNOCO, INC.,
                                    as Sponsor


                                    By: /s/ PAUL A. MULHOLLAND
                                       --------------------------------------
                                    Name: Paul A. Mulholland
                                    Title: Treasurer


                                    BANKERS TRUST COMPANY,
                                    as Property Trustee


                                    By: /s/ CHRISTOPHER LEW
                                       --------------------------------------
                                    Name: Christopher Lew
                                    Title: Associate


                                    BANKERS TRUST (DELAWARE),
                                    as Delaware Trustee


                                    By: /s/ M. LISA WILKINS
                                       --------------------------------------
                                    Name: M. Lisa Wilkins
                                    Title: Assistant Vice President

                                    PAUL A. MULHOLLAND
                                    as Regular Trustee


                                    /s/ PAUL A. MULHOLLAND
                                    -----------------------------------------

                                      -4-