<PAGE>

                                                                  Exhibit 4.16.1

--------------------------------------------------------------------------------

                                  SUNOCO, INC.

                               GUARANTEE AGREEMENT

                                SUNOCO CAPITAL I

                                Dated as of [___]

--------------------------------------------------------------------------------
<PAGE>

                                TABLE OF CONTENTS

                                                                            Page
                                                                            ----
                                    ARTICLE I

                DEFINITIONS AND INTERPRETATION ..............................  1

SECTION 1.1  Definitions and Interpretation .................................  1

                                   ARTICLE II

                              TRUST INDENTURE ACT ...........................  5

SECTION 2.1  Trust Indenture Act; Application ...............................  5
SECTION 2.2  Lists of Holders of Securities .................................  5
SECTION 2.3  Reports by the Preferred Guarantee Trustee .....................  6
SECTION 2.4  Periodic Reports to Preferred Guarantee Trustee ................  6
SECTION 2.5  Evidence of Compliance with Conditions Precedent ...............  6
SECTION 2.6  Events of Default; Waiver ......................................  6
SECTION 2.7  Event of Default; Notice .......................................  6
SECTION 2.8  Conflicting Interests ..........................................  7
SECTION 2.9  Preferred Guarantee Trustee May File Proofs of Claim ...........  7

                                   ARTICLE III

                          POWERS, DUTIES AND RIGHTS OF
                          PREFERRED GUARANTEE TRUSTEE .......................  7

SECTION 3.1  Powers and Duties of the Preferred Guarantee Trustee ...........  7
SECTION 3.2  Certain Rights of Preferred Guarantee Trustee ..................  9
SECTION 3.3  Not Responsible for Recitals or Issuance of Preferred Securities
                  Guarantee ................................................. 10

                                   ARTICLE IV

                         PREFERRED GUARANTEE TRUSTEE ........................ 11

SECTION 4.1  Preferred Guarantee Trustee; Eligibility ....................... 11
SECTION 4.2  Appointment, Removal and Resignation of Preferred Guarantee
                  Trustee ................................................... 11

                                    ARTICLE V

                                  GUARANTEE ................................. 12

SECTION 5.1  Guarantee ...................................................... 12

                                      -i-
<PAGE>

                                                                            Page
                                                                            ----

SECTION 5.2  Waiver of Notice and Demand .................................... 12
SECTION 5.3  Obligations Not Affected ....................................... 13
SECTION 5.4  Rights of Holders .............................................. 14
SECTION 5.5  Guarantee of Payment ........................................... 14
SECTION 5.6  Subrogation .................................................... 14
SECTION 5.7  Independent Obligations ........................................ 14

                                   ARTICLE VI

                  LIMITATION OF TRANSACTIONS; SUBORDINATION ................. 15

SECTION 6.1  Limitation of Transactions ..................................... 15
SECTION 6.2  Ranking ........................................................ 15

                                   ARTICLE VII

                                 TERMINATION ................................ 15

SECTION 7.1  Termination .................................................... 15

                                  ARTICLE VIII

                               INDEMNIFICATION .............................. 16

SECTION 8.1  Exculpation .................................................... 16
SECTION 8.2  Indemnification ................................................ 16
SECTION 8.3  Compensation. .................................................. 16

                                   ARTICLE IX

                                MISCELLANEOUS ............................... 17

SECTION 9.1  Successors and Assigns ......................................... 17
SECTION 9.2  Amendments ..................................................... 17
SECTION 9.3  Notices ........................................................ 17
SECTION 9.4  Benefit ........................................................ 18
SECTION 9.5  Governing Law .................................................. 18
SECTION 9.6  Counterparts ................................................... 18

                                     -ii-
<PAGE>

                    PREFERRED SECURITIES GUARANTEE AGREEMENT

     This GUARANTEE AGREEMENT (the "Preferred Securities Guarantee"), dated as
of [___], is executed and delivered by Sunoco, Inc., a Pennsylvania corporation
(the "Guarantor"), and Bankers Trust Company, a New York banking corporation, as
trustee (the "Preferred Guarantee Trustee"), for the benefit of the Holders (as
defined herein) from time to time of the Preferred Securities (as defined
herein) of Sunoco Capital I, a Delaware statutory business trust (the "Issuer").

     WHEREAS, pursuant to an Amended and Restated Declaration of Trust (the
"Declaration"), dated as of [___], among the trustees of the Issuer named
therein, the Guarantor, as sponsor, and the holders from time to time of
undivided beneficial interests in the assets of the Issuer, the Issuer is
issuing on the date hereof [___] trust preferred securities, having an aggregate
liquidation amount of $[___] (plus up to an additional [___] trust preferred
securities, having an aggregate liquidation amount of $[___], to cover
over-allotments), designated the [___]% Trust Preferred Securities (the
"Preferred Securities");

     WHEREAS, as incentive for the Holders (as defined herein) to purchase the
Preferred Securities, the Guarantor desires irrevocably and unconditionally to
agree, to the extent set forth in this Preferred Securities Guarantee, to pay to
the Holders of the Preferred Securities the Guarantee Payments (as defined
herein) and to make certain other payments on the terms and conditions set forth
herein.

     WHEREAS, the Guarantor is also executing and delivering a guarantee
agreement (the "Common Securities Guarantee") in substantially identical terms
to this Preferred Securities Guarantee for the benefit of the holders of the
Common Securities (as defined herein), except that if an Event of Default (as
defined in the Indenture), has occurred and is continuing, the rights of holders
of the Common Securities to receive Guarantee Payments under the Common
Securities Guarantee are subordinated to the rights of Holders of Preferred
Securities to receive Guarantee Payments under this Preferred Securities
Guarantee.

     NOW, THEREFORE, in consideration of the purchase by each Holder of
Preferred Securities, which purchase the Guarantor hereby agrees shall benefit
the Guarantor, the Guarantor executes and delivers this Preferred Securities
Guarantee for the benefit of the Holders.

                                    ARTICLE I

                         DEFINITIONS AND INTERPRETATION

SECTION 1.1 Definitions and Interpretation

     In this Preferred Securities Guarantee, unless the context otherwise
requires:

            (a) Capitalized terms used in this Preferred Securities Guarantee
     but not defined in the preamble above have the respective meanings assigned
     to them in this Section 1.1;
<PAGE>

                                                                               2

          (b) a term defined anywhere in this Preferred Securities Guarantee has
     the same meaning throughout;

          (c) all references to "the Preferred Securities Guarantee" or "this
     Preferred Securities Guarantee" are to this Preferred Securities Guarantee
     as modified, supplemented or amended from time to time;

          (d) all references in this Preferred Securities Guarantee to Articles
     and Sections are to Articles and Sections of this Preferred Securities
     Guarantee, unless otherwise specified;

          (e) a term defined in the Trust Indenture Act has the same meaning
     when used in this Preferred Securities Guarantee, unless otherwise defined
     in this Preferred Securities Guarantee or unless the context otherwise
     requires; and

          (f) a reference to the singular includes the plural and vice versa.

     "Affiliate" has the same meaning as given to that term in Rule 405 of the
     Securities Act of 1933, as amended, or any successor rule thereunder.

     "Business Day" means any day other than a day on which banking institutions
     in the City of New York, New York are authorized or required by any
     applicable law to close.

     "Common Securities" means the securities representing common undivided
     beneficial interests in the assets of the Issuer and having the terms set
     forth in Exhibit B to the Declaration.

     "Corporate Trust Office" means the office of the Preferred Guarantee
     Trustee at which the corporate trust business of the Preferred Guarantee
     Trustee shall, at any particular time, be principally administered, which
     office at the date of execution of this Agreement is located at Bankers
     Trust Company, Corporate, Trust and Agency Services, 4 Albany Street, New
     York, New York 10006.

     "Covered Person" means any Holder or beneficial owner of Preferred
     Securities.

     "Debentures" means the series of subordinated debt securities of the
     Guarantor designated the [___]% [Subordinated Debt Securities ] due [___]
     held by the Institutional Trustee (as defined in the Declaration) of the
     Issuer.

     "Event of Default" means a default by the Guarantor on any of its payment
     or other obligations under this Preferred Securities Guarantee; provided,
     however, that, with respect to a default in payment of any Guarantee
     Payment, any such default shall constitute an Event of Default only if the
     Guarantor shall have received notice of such default and shall not  have
     cured such default within sixty (60) days after receipt of such notice.
<PAGE>

                                                                               3

     "Guarantee Payments" means the following payments or distributions, without
     duplication, with respect to the Preferred Securities, to the extent not
     paid or made by or on behalf of the Issuer:

     (i) any accrued and unpaid Distributions (as defined in the Declaration)
     that are required to be paid on such Preferred Securities to the extent the
     Issuer shall have funds available therefor, (ii) the redemption price,
     including all accrued and unpaid Distributions to the date of redemption
     (the "Redemption Price") to the extent the Issuer has funds available
     therefor, with respect to any Preferred Securities called for redemption by
     the Issuer, and (iii) upon a voluntary or involuntary dissolution,
     winding-up or termination of the Issuer (other than in connection with the
     distribution of Debentures to the Holders in exchange for Preferred
     Securities or the redemption of the Preferred Securities in full upon the
     maturity or redemption of the Debentures, as provided in the Declaration),
     the lesser of (a) the aggregate of the liquidation amount and all accrued
     and unpaid Distributions on the Preferred Securities to the date of
     payment, to the extent the Issuer shall have funds available therefor, and
     (b) the amount of assets of the Issuer remaining available for distribution
     to Holders in liquidation of the Issuer (in either case, the "Liquidation
     Distribution") as required by applicable law. If an event of default under
     the Indenture has occurred and is continuing, the rights of holders of the
     Common Securities to receive payments under the Common Securities Guarantee
     Agreement are subordinated to the rights of Holders of Preferred Securities
     to receive Guarantee Payments.

     "Holder" shall mean any holder, as registered on the books and records of
     the Issuer of any Preferred Securities; provided, however, that, in
     determining whether the holders of the requisite percentage of Preferred
     Securities have given any request, notice, consent or waiver hereunder,
     "Holder" shall not include the Guarantor or any Affiliate of the Guarantor.

     "Indemnified Person" means the Preferred Guarantee Trustee, any Affiliate
     of the Preferred Guarantee Trustee, or any officers, directors,
     shareholders, members, partners, employees, representatives, nominees,
     custodians or agents of the Preferred Guarantee Trustee.

     "Indenture" means the Indenture dated as of May 15, 1994 among the
     Guarantor (the "Debenture Issuer") and Bankers Trust Company, as trustee,
     and any indenture supplemental thereto pursuant to which certain
     subordinated debt securities of the Debenture Issuer are to be issued to
     the Property Trustee of the Issuer.

     "Majority in liquidation amount of the Preferred Securities" means, except
     as provided by the Trust Indenture Act, a vote by Holder(s) of Preferred
     Securities, voting together as a single class, of more than 50% of the
     liquidation amount (including the stated amount that would be paid on
     redemption, liquidation or otherwise, plus accrued and unpaid Distributions
     to the date upon which the voting percentages are determined) of all
     Preferred Securities. In determining whether
<PAGE>

                                                                               4

     Holders of the requisite amount of Preferred Securities have voted,
     Preferred Securities which are owned by the Guarantor or any Affiliate of
     the Guarantor shall be disregarded for the purpose of any such
     determination.

     "Officers' Certificate" means, with respect to any Person, a certificate
     signed by two authorized officers of such Person. Any Officers' Certificate
     delivered with respect to compliance with a condition or covenant provided
     for in this Preferred Securities Guarantee shall include:

          (a) a statement that each officer signing the Officers' Certificate
     has read the covenant or condition and the definition relating thereto;

          (b) a brief statement of the nature and scope of the examination or
     investigation undertaken by each officer in rendering the Officers'
     Certificate;

          (c) a statement that each such officer has made such examination or
     investigation as, in such officer's opinion, is necessary to enable such
     officer to express an informed opinion as to whether or not such covenant
     or condition has been complied with; and

          (d) a statement as to whether, in the opinion of each such officer,
     such condition or covenant has been complied with.

     "Person" means a legal person, including any individual, corporation,
     estate, partnership, joint venture, incorporated or unincorporated
     association, joint stock company, limited liability company, trust, or
     government or any agency or political subdivision thereof, or any other
     entity of whatever nature.

     "Preferred Guarantee Trustee" means Bankers Trust Company, a New York
     banking corporation, until a Successor Preferred Guarantee Trustee has been
     appointed and has accepted such appointment pursuant to the terms of this
     Preferred Securities Guarantee and thereafter means each such Successor
     Preferred Guarantee Trustee.

     "Responsible Officer" means, with respect to the Preferred Guarantee
     Trustee, any officer within the corporate trust department of the Preferred
     Guarantee Trustee, including any director, principal, vice president, any
     assistant vice president, associate or other officer of the corporate trust
     department of the Preferred Guarantee Trustee customarily performing
     functions similar to those performed by any of the above designated
     officers and also means, with respect to a particular corporate trust
     matter, any other officer to whom such matter is referred because of that
     officer's knowledge of and familiarity with the particular subject.
<PAGE>

                                                                               5

     "Successor Preferred Guarantee Trustee" means a successor Preferred
     Guarantee Trustee possessing the qualifications to act as Preferred
     Guarantee Trustee under Section 4.1.

     "Trust Indenture Act" means the Trust Indenture Act of 1939, as amended.

     "Trust Securities" means the Common Securities and the Preferred
     Securities.

                                   ARTICLE II

                               TRUST INDENTURE ACT

SECTION 2.1 Trust Indenture Act; Application

     (a) This Preferred Securities Guarantee is subject to the provisions of the
Trust Indenture Act that are required to be part of this Preferred Securities
Guarantee and shall, to the extent applicable, be governed by such provisions;
and

     (b) if and to the extent that any provision of this Preferred Securities
Guarantee limits, qualifies or conflicts with the duties imposed by Section 310
to 317, inclusive, of the Trust Indenture Act, such imposed duties shall
control.

     (c) The application of the Trust Indenture Act to this Preferred Securities
Guarantee shall not affect the nature of the Preferred Securities as equity
securities representing preferred undivided beneficial interests in the assets
of the Issuer.

SECTION 2.2 Lists of Holders of Securities

     (a) The Guarantor shall provide the Preferred Guarantee Trustee (unless the
Guarantee Trustee is the registrar of the Preferred Securities) with a list, in
such form as the Preferred Guarantee Trustee may reasonably require, of the
names and addresses of the Holders of the Preferred Securities ("List of
Holders"), (i) within 14 days after each record date for the payment of
Distributions, as of such date and (ii) at any other time within 30 days of
receipt by the Guarantor of a written request for a List of Holders as of a date
no more than 14 days before such List of Holders is given to the Preferred
Guarantee Trustee provided, that the Guarantor shall not be obligated to provide
such List of Holders at any time the List of Holders does not differ from the
most recent List of Holders given to the Preferred Guarantee Trustee by the
Guarantor. The Preferred Guarantee Trustee may destroy any List of Holders
previously given to it on receipt of a new List of Holders.

     (b) The Preferred Guarantee Trustee shall comply with its obligations under
Sections 311(a), 311(b) and Section 312(b) of the Trust Indenture Act.
<PAGE>

                                                                               6

SECTION 2.3 Reports by the Preferred Guarantee Trustee

     Within 60 days after May 15 of each year, the Preferred Guarantee Trustee
shall provide to the Holders of the Preferred Securities such reports as are
required by Section 313 of the Trust Indenture Act, if any, in the form and in
the manner provided by Section 313 of the Trust Indenture Act. The Preferred
Guarantee Trustee shall also comply with the requirements of Section 313(d) of
the Trust Indenture Act.

SECTION 2.4 Periodic Reports to Preferred Guarantee Trustee

     The Guarantor shall provide to the Preferred Guarantee Trustee such
documents, reports and information as required by Section 314 (if any) and the
compliance certificate required by Section 314 of the Trust Indenture Act in the
form, in the manner and at the times required by Section 314 of the Trust
Indenture Act.

SECTION 2.5 Evidence of Compliance with Conditions Precedent

     The Guarantor shall provide to the Preferred Guarantee Trustee such
evidence of compliance with any conditions precedent, if any, provided for in
this Preferred Securities Guarantee that relate to any of the matters set forth
in Section 314(c) of the Trust Indenture Act. Any certificate or opinion
required to be given by an officer pursuant to Section 314(c)(1) may be given in
the form of an Officers' Certificate.

SECTION 2.6 Events of Default; Waiver

     The Holders of a Majority in liquidation amount of Preferred Securities
may, by vote or written consent, on behalf of the Holders of all of the
Preferred Securities, waive any past Event of Default and its consequences. Upon
such waiver, any such Event of Default shall cease to exist, and any Event of
Default arising therefrom shall be deemed to have been cured, for every purpose
of this Preferred Securities Guarantee, but no such waiver shall extend to any
subsequent or other default or Event of Default or impair any right consequent
thereon.

SECTION 2.7 Event of Default; Notice

     (a) The Preferred Guarantee Trustee shall, within 90 days after the
occurrence of an Event of Default, actually known to a Responsible Officer of
the Guarantee Trustee, transmit by mail, first class postage prepaid, to the
Holders of the Preferred Securities, notices of all Events of Default actually
known to a Responsible Officer of the Preferred Guarantee Trustee, unless such
defaults have been cured before the giving of such notice, provided, that, the
Preferred Guarantee Trustee shall be protected in withholding such notice if and
so long as its board of directors, the executive committee of its board of
directors or a committee of its Responsible Officers, in good faith determines
that the withholding of such notice is in the interests of the Holders of the
Preferred Securities.

     (b) The Preferred Guarantee Trustee shall not be deemed to have knowledge
of any Event of Default unless the Preferred Guarantee Trustee shall have
received written notice, or of which a Responsible Officer of the Preferred
Guarantee Trustee charged with the administration of the Declaration shall have
obtained actual knowledge.
<PAGE>

                                                                               7

SECTION 2.8 Conflicting Interests

     (a) The Declaration shall be deemed to be specifically described in this
Preferred Securities Guarantee for the purposes of clause (i) of the first
proviso contained in Section 310(b) of the Trust Indenture Act.

     (b) The Guarantee Trustee shall comply with its obligations under Sections
310(b) and 311 of the Trust Indenture Act.

SECTION 2.9 Preferred Guarantee Trustee May File Proofs of Claim

     Upon the occurrence of an Event of Default, the Preferred Guarantee Trustee
is hereby authorized to (a) recover judgment, in its own name and as trustee of
an express trust, against the Guarantor for the whole amount of any Guarantee
Payments remaining unpaid and (b) file such proofs of claim and other papers or
documents as may be necessary or advisable in order to have its claims and those
of the Holders of the Preferred Securities allowed in any judicial proceedings
relative to the Guarantor, its creditors or its property.

                                   ARTICLE III

                          POWERS, DUTIES AND RIGHTS OF
                           PREFERRED GUARANTEE TRUSTEE

SECTION 3.1 Powers and Duties of the Preferred Guarantee Trustee

     (a) This Preferred Securities Guarantee shall be held by the Preferred
Guarantee Trustee for the benefit of the Holders of the Preferred Securities,
and the Preferred Guarantee Trustee shall not transfer this Preferred Securities
Guarantee to any Person except a Holder of Preferred Securities exercising his
or her rights pursuant to Section 5.4(b) or to a Successor Preferred Guarantee
Trustee on acceptance by such Successor Preferred Guarantee Trustee of its
appointment to act as Successor Preferred Guarantee Trustee. The right, title
and interest of the Preferred Guarantee Trustee shall automatically vest in any
Successor Preferred Guarantee Trustee, and such vesting and cessation of title
shall be effective whether or not conveyancing documents have been executed and
delivered pursuant to the appointment of such Successor Preferred Guarantee
Trustee.

     (b) If an Event of Default actually known to a Responsible Officer of the
Preferred Guarantee Trustee has occurred and is continuing, the Preferred
Guarantee Trustee shall enforce this Preferred Securities Guarantee for the
benefit of the Holders of the Preferred Securities.

     (c) The Preferred Guarantee Trustee, before the occurrence of any Event of
Default and after the curing or waiving of all Events of Default that may have
occurred, shall undertake to perform only such duties as are specifically set
forth in this Preferred Securities Guarantee, and no implied covenants shall be
read into this Preferred Securities Guarantee against the Preferred Guarantee
Trustee. In case an Event of Default has occurred (that has not been cured or
waived
<PAGE>

                                                                               8

pursuant to Section 2.6) and is actually known to a Responsible Officer of the
Preferred Guarantee Trustee, the Preferred Guarantee Trustee shall exercise such
of the rights and powers vested in it by this Preferred Securities Guarantee,
and use the same degree of care and skill in its exercise thereof, as a prudent
person would exercise or use under the circumstances in the conduct of his or
her own affairs.

     (d) No provision of this Preferred Securities Guarantee shall be construed
to relieve the Preferred Guarantee Trustee from liability for its own negligent
action, its own negligent failure to act, or its own willful misconduct, except
that:

          (i) prior to the occurrence of any Event of Default and after the
curing or waiving of all such Events of Default that may have occurred:

          (A) the duties and obligations of the Preferred Guarantee Trustee
     shall be determined solely by the express provisions of this Preferred
     Securities Guarantee, and the Preferred Guarantee Trustee shall not be
     liable except for the performance of such duties and obligations as are
     specifically set forth in this Preferred Securities Guarantee, and no
     implied covenants or obligations shall be read into this Preferred
     Securities Guarantee against the Preferred Guarantee Trustee; and

          (B) in the absence of bad faith on the part of the Preferred Guarantee
     Trustee, the Preferred Guarantee Trustee may conclusively rely, as to the
     truth of the statements and the correctness of the opinions expressed
     therein, upon any certificates or opinions furnished to the Preferred
     Guarantee Trustee and conforming to the requirements of this Preferred
     Securities Guarantee; but in the case of any such certificates or opinions
     that by any provision hereof, or of the Trust Indenture Act, are
     specifically required to be furnished to the Preferred Guarantee Trustee,
     the Preferred Guarantee Trustee shall be under a duty to examine the same
     to determine whether or not they conform to the requirements of this
     Preferred Securities Guarantee hereof, or of the Trust Indenture Act, as
     the case may be, but need not confirm or investigate the accuracy of any
     mathematical calculations or other facts stated therein;

          (ii) the Preferred Guarantee Trustee shall not be liable for any error
of judgment made in good faith by a Responsible Officer of the Preferred
Guarantee Trustee, unless it shall be proved that the Preferred Guarantee
Trustee was negligent in ascertaining the pertinent facts upon which such
judgment was made;

          (iii) the Preferred Guarantee Trustee shall not be liable with respect
to any action taken or omitted to be taken by it in good faith in accordance
with the written direction of the Holders of not less than a Majority in
liquidation amount of the Preferred Securities relating to the time, method and
place of conducting any proceeding for any remedy available to the Preferred
Guarantee Trustee, or exercising any trust or power conferred upon the Preferred
Guarantee Trustee under this Preferred Securities Guarantee; and

          (iv) no provision of this Preferred Securities Guarantee shall require
the Preferred Guarantee Trustee to expend or risk its own funds or otherwise
incur personal financial liability in
<PAGE>

                                                                               9


the performance of any of its duties or in the exercise of any of its rights or
powers, if the Preferred Guarantee Trustee shall have reasonable grounds for
believing that the repayment of such funds or liability is not reasonably
assured to it under the terms of this Preferred Securities Guarantee or
indemnity, reasonably satisfactory to the Preferred Guarantee Trustee, against
such risk or liability is not reasonably assured to it.

SECTION 3.2 Certain Rights of Preferred Guarantee Trustee

     (a)  Subject to the provisions of Section 3.1:

          (i)   The Preferred Guarantee Trustee may conclusively rely, and shall
be fully protected in acting or refraining from acting upon, any resolution,
certificate, statement, instrument, opinion, report, notice, request, direction,
consent, order, bond, debenture, note, other evidence of indebtedness or other
paper or document (whether in its original or facsimile form) reasonably
believed by it to be genuine and to have been signed, sent or presented by the
proper party or parties.

          (ii)  Whenever, in the administration of this Preferred Securities
Guarantee, the Preferred Guarantee Trustee shall deem it desirable that a matter
be proved or established before taking, suffering or omitting any action
hereunder, the Preferred Guarantee Trustee (unless other evidence is herein
specifically prescribed) may, in the absence of bad faith on its part, request
and conclusively rely upon an Officers' Certificate which, upon receipt of such
request, shall be promptly delivered by the Guarantor.

          (iii) The Preferred Guarantee Trustee shall have no duty to see to any
recording, filing or registration of any instrument (or any rerecording,
refiling or registration thereof).

          (iv)  The Preferred Guarantee Trustee may consult with counsel
selected by it in good faith and with due care, and the written advice or
opinion of such counsel with respect to legal matters shall be full and complete
authorization and protection in respect of any action taken, suffered or omitted
by it hereunder in good faith and in reliance upon, and in accordance with such
advice or opinion. Such counsel may be counsel to the Guarantor or any of its
Affiliates and may include any of its employees. The Preferred Guarantee Trustee
shall have the right at any time to seek instructions concerning the
administration of this Preferred Securities Guarantee from any court of
competent jurisdiction.

          (v)   The Preferred Guarantee Trustee shall be under no obligation to
exercise any of the rights or powers vested in it by this Preferred Securities
Guarantee at the request or direction of any Holder, unless such Holder shall
have provided to the Preferred Guarantee Trustee such security and indemnity,
satisfactory to the Preferred Guarantee Trustee, against the costs, expenses
(including attorneys' fees and expenses and the expenses of the Preferred
Guarantee Trustee's agents, nominees or custodians) and liabilities that might
be incurred by it in complying with such request or direction, including such
reasonable advances as may be requested by the Preferred Guarantee Trustee;
provided that, nothing contained in this Section 3.2(a)(v) shall be taken to
relieve the Preferred Guarantee Trustee, upon the occurrence of an Event of
Default, of its obligation to exercise the rights and powers vested in it by
this Preferred Securities Guarantee.
<PAGE>

                                                                              10

          (vi)   The Preferred Guarantee Trustee shall not be bound to make any
investigation into the facts or matters stated in any resolution, certificate,
statement, instrument, opinion, report, notice, request, direction, consent,
order, bond, debenture, note, other evidence of indebtedness or other paper or
document, but the Preferred Guarantee Trustee, in its discretion, may make such
further inquiry or investigation into such facts or matters as it may see fit,
at the expense of the Guarantor and shall incur no liability or additional
liability of any kind by reason of such inquiry or investigation.

          (vii)  The Preferred Guarantee Trustee may execute any of the trusts
or powers hereunder or perform any duties hereunder either directly or by or
through agents, nominees, custodians or attorneys, and the Preferred Guarantee
Trustee shall not be responsible for any misconduct or negligence on the part of
any agent, nominee, custodian or attorney appointed with due care by it
hereunder.

          (viii) Any action taken by the Preferred Guarantee Trustee or its
agents hereunder shall bind the Holders of the Preferred Securities, and the
signature of the Preferred Guarantee Trustee or its agents alone shall be
sufficient and effective to perform any such action. No third party shall be
required to inquire as to the authority of the Preferred Guarantee Trustee to so
act or as to its compliance with any of the terms and provisions of this
Preferred Securities Guarantee, both of which shall be conclusively evidenced by
the Preferred Guarantee Trustee or its agent taking such action.

          (ix)   Whenever in the administration of this Preferred Securities
Guarantee the Preferred Guarantee Trustee shall deem it desirable to receive
instructions with respect to enforcing any remedy or right or taking any other
action hereunder, the Preferred Guarantee Trustee (i) may request instructions
from the Holders of a Majority in liquidation amount of the Preferred
Securities, (ii) may refrain from enforcing such remedy or right or taking such
other action until such instructions are received, and (iii) shall be protected
in conclusively relying on or acting in accordance with such instructions.

     (b) No provision of this Preferred Securities Guarantee shall be deemed to
impose any duty or obligation on the Preferred Guarantee Trustee to perform any
act or acts or exercise any right, power, duty or obligation conferred or
imposed on it in any jurisdiction in which it shall be illegal, or in which the
Preferred Guarantee Trustee shall be unqualified or incompetent in accordance
with applicable law, to perform any such act or acts or to exercise any such
right, power, duty or obligation. No permissive power or authority available to
the Preferred Guarantee Trustee shall be construed to be a duty.

SECTION 3.3 Not Responsible for Recitals or Issuance of Preferred Securities
            Guarantee

     The recitals contained in this Preferred Securities Guarantee shall be
taken as the statements of the Guarantor, and the Preferred Guarantee Trustee
does not assume any responsibility for their correctness. The Preferred
Guarantee Trustee makes no representation as to the validity or sufficiency of
this Preferred Securities Guarantee.
<PAGE>

                                                                              11


                                   ARTICLE IV

                           PREFERRED GUARANTEE TRUSTEE

SECTION 4.1 Preferred Guarantee Trustee; Eligibility

     (a)  There shall at all times be a Preferred Guarantee Trustee which shall:

          (i)  not be an Affiliate of the Guarantor; and

          (ii) be a corporation organized and doing business under the laws of
the United States of America or any State or Territory thereof or of the
District of Columbia, or a corporation or Person permitted by the Securities and
Exchange Commission to act as an institutional trustee under the Trust Indenture
Act, authorized under such laws to exercise corporate trust powers, having a
combined capital and surplus of at least 50 million U.S. dollars ($50,000,000),
and subject to supervision or examination by Federal, State, Territorial or
District of Columbia authority. If such corporation publishes reports of
condition at least annually, pursuant to law or to the requirements of the
supervising or examining authority referred to above, then, for the purposes of
this Section 4.1(a)(ii), the combined capital and surplus of such corporation
shall be deemed to be its combined capital and surplus as set forth in its most
recent report of condition so published.

     (b) If at any time the Preferred Guarantee Trustee shall cease to be
eligible to so act under Section 4.1(a), the Preferred Guarantee Trustee shall
immediately resign in the manner and with the effect set out in Section 4.2(c).

     (c) If the Preferred Guarantee Trustee has or shall acquire any
"conflicting interest" within the meaning of Section 310(b) of the Trust
Indenture Act, the Preferred Guarantee Trustee and Guarantor shall in all
respects comply with the provisions of Section 310(b) of the Trust Indenture
Act.

SECTION 4.2 Appointment, Removal and Resignation of Preferred Guarantee Trustee

     (a) Subject to Section 4.2(b), the Preferred Guarantee Trustee may be
appointed or removed without cause at any time by the Guarantor.

     (b) The Preferred Guarantee Trustee shall not be removed in accordance with
Section 4.2(a) until a Successor Preferred Guarantee Trustee has been appointed
and has accepted such appointment by written instrument executed by such
Successor Preferred Guarantee Trustee and delivered to the Guarantor.

     (c) The Preferred Guarantee Trustee appointed to office shall hold office
until a Successor Preferred Guarantee Trustee shall have been appointed or until
its removal or resignation. The Preferred Guarantee Trustee may resign from
office (without need for prior or subsequent accounting) by an instrument in
writing executed by the Preferred Guarantee Trustee and delivered to the
Guarantor, which resignation shall not take effect until a Successor Preferred
Guarantee Trustee has been appointed and has accepted such appointment by
instrument in writing executed
<PAGE>

                                                                              12


by such Successor Preferred Guarantee Trustee and delivered to the Guarantor and
the resigning Preferred Guarantee Trustee.

     (d) If no Successor Preferred Guarantee Trustee shall have been appointed
and accepted appointment as provided in this Section 4.2 within 60 days after
delivery to the Guarantor of an instrument of removal or resignation, the
resigning Preferred Guarantee Trustee may petition any court of competent
jurisdiction for appointment of a Successor Preferred Guarantee Trustee. Such
court may thereupon, after prescribing such notice, if any, as it may deem
proper, appoint a Successor Preferred Guarantee Trustee.

     (e) No Preferred Guarantee Trustee shall be liable for the acts or
omissions to act of any Successor Preferred Guarantee Trustee.

     (f) Upon termination of this Preferred Securities Guarantee or removal or
resignation of the Preferred Guarantee Trustee pursuant to this Section 4.2, the
Guarantor shall pay to the Preferred Guarantee Trustee all amounts owning for
fees and reimbursement of expenses which have accrued to the date of such
termination, removal or resignation.

     (g) The Guarantor shall promptly notify the Holders of the resignation,
removal or appointment of the Preferred Guarantee Trustee.

                                    ARTICLE V

                                    GUARANTEE

SECTION 5.1 Guarantee

     The Guarantor irrevocably and unconditionally agrees to pay in full to the
Holders the Guarantee Payments (without duplication of amounts theretofore paid
by the Issuer), as and when due, regardless of any defense, right of set-off or
counterclaim that the Issuer may have or assert. The Guarantor's obligation to
make a Guarantee Payment may be satisfied by direct payment of the required
amounts by the Guarantor to the Holders or by causing the Issuer to pay such
amounts to the Holders.

SECTION 5.2 Waiver of Notice and Demand

     The Guarantor hereby waives notice of acceptance of this Preferred
Securities Guarantee and of any liability to which it applies or may apply,
presentment, demand for payment, any right to require a proceeding first against
the Issuer or any other Person before proceeding against the Guarantor, protest,
notice of nonpayment, notice of dishonor, notice of redemption and all other
notices and demands. Notwithstanding anything to the contrary herein, the
Guarantor retains all of its rights under the Indenture to (i) extend the
interest payment period on the Debentures and the Guarantor shall not be
obligated hereunder to make any Guarantee Payments during any Extended Interest
Payment Period (as defined in the Indenture) with respect to the Distributions
(as defined
<PAGE>

                                                                              13

in the Declaration) on the Preferred Securities, and (ii) change the maturity
date of the Debentures to the extent permitted by the Indenture.

SECTION 5.3 Obligations Not Affected

     The obligations, covenants, agreements and duties of the Guarantor under
this Preferred Securities Guarantee shall in no way be affected or impaired by
reason of the happening from time to time of any of the following:

     (a) the release or waiver, by operation of law or otherwise, of the
performance or observance by the Issuer of any express or implied agreement,
covenant, term or condition relating to the Preferred Securities to be performed
or observed by the Issuer;

     (b) the extension of time for the payment by the Issuer of all or any
portion of the Distributions, Redemption Price, Liquidation Distribution or any
other sums payable under the terms of the Preferred Securities or the extension
of time for the performance of any other obligation under, arising out of, or in
connection with, the Preferred Securities (other than an extension of time for
payment of Distributions, Redemption Price, Liquidation Distribution or other
sum payable that results from the extension of any interest payment period on
the Debentures or any extension of the maturity date of the Debentures permitted
by the Indenture);

     (c) any failure, omission, delay or lack of diligence on the part of the
Holders to enforce, assert or exercise any right, privilege, power or remedy
conferred on the Holders pursuant to the terms of the Preferred Securities, or
any action on the part of the Issuer granting indulgence or extension of any
kind;

     (d) the voluntary or involuntary liquidation, dissolution, sale of any
collateral, receivership, insolvency, bankruptcy, assignment for the benefit of
creditors, reorganization, arrangement, composition or readjustment of debt of,
or other similar proceedings affecting, the Issuer or any of the assets of the
Issuer;

     (e) any invalidity of, or defect or deficiency in, the Preferred
Securities;

     (f) the settlement or compromise of any obligation guaranteed hereby or
hereby incurred; or

     (g) any other circumstance whatsoever that might otherwise constitute a
legal or equitable discharge or defense of a guarantor, it being the intent of
this Section 5.3 that the obligations of the Guarantor hereunder shall be
absolute and unconditional under any and all circumstances.

     There shall be no obligation of the Holders to give notice to, or obtain
consent of, the Guarantor with respect to the happening of any of the foregoing.
<PAGE>

                                                                              14

SECTION 5.4 Rights of Holders

     (a) Holders of a Majority in liquidation amount of the Preferred Securities
have the right to direct the time, method and place of conducting of any
proceeding for any remedy available to the Preferred Guarantee Trustee in
respect of this Preferred Securities Guarantee or exercising any trust or power
conferred upon the Preferred Guarantee Trustee under this Preferred Securities
Guarantee.

     (b) If the Preferred Guarantee Trustee fails to enforce such Preferred
Securities Guarantee, any Holder of Preferred Securities may institute a legal
proceeding directly against the Guarantor to enforce such Holder's rights under
this Preferred Securities Guarantee, without first instituting a legal
proceeding against the Issuer, the Preferred Guarantee Trustee or any other
person or entity. Notwithstanding the foregoing, if the Guarantor has failed to
make a Guarantee Payment, a Holder may, subject to the subordination provisions
of Section 6.2, directly institute a proceeding against the Guarantor for
enforcement of the Preferred Securities Guarantee for such payment to the Holder
of the principal of or interest on the Debentures on or after the respective due
dates specified in the Debentures, and the amount of the payment will be based
on the Holder's pro rata share of the amount due and owing on all of the
Preferred Securities. The Guarantor waives any right or remedy to require that
any action be brought first against the Issuer or any other person or entity
before proceeding directly against the Guarantor.

SECTION 5.5 Guarantee of Payment

     This Preferred Securities Guarantee creates a guarantee of payment and not
of collection.

SECTION 5.6 Subrogation

     The Guarantor shall be subrogated to all (if any) rights of the Holders of
Preferred Securities against the Issuer in respect of any amounts paid to such
Holders by the Guarantor under this Preferred Securities Guarantee; provided,
however, that the Guarantor shall not (except to the extent required by
mandatory provisions of law) be entitled to enforce or exercise any right that
it may acquire by way of subrogation or any indemnity, reimbursement or other
agreement, in all cases as a result of payment under this Preferred Securities
Guarantee, if, at the time of any such payment, any amounts are due and unpaid
under this Preferred Securities Guarantee. If any amount shall be paid to the
Guarantor in violation of the preceding sentence, the Guarantor agrees to hold
such amount in trust for the Holders and to pay over such amount to the Holders.

SECTION 5.7 Independent Obligations

     The Guarantor acknowledges that its obligations hereunder are independent
of the obligations of the Issuer with respect to the Preferred Securities, and
that the Guarantor shall be liable as principal and as debtor hereunder to make
Guarantee Payments pursuant to the terms of this Preferred Securities Guarantee
notwithstanding the occurrence of any event referred to in subsections (a)
through (g), inclusive, of Section 5.3 hereof.
<PAGE>

                                                                              15

                                   ARTICLE VI

                    LIMITATION OF TRANSACTIONS; SUBORDINATION

SECTION 6.1 Limitation of Transactions

     So long as any Preferred Securities remain outstanding, if there shall have
occurred an Event of Default or an event of default under the Declaration, then
(a) the Guarantor shall not declare or pay any dividend on, make any
distributions with respect to, or redeem, purchase, acquire or make a
liquidation payment with respect to, any of its capital stock (other than (i)
purchases or acquisitions of shares of the common stock of the Guarantor in
connection with the satisfaction by the Guarantor of its obligations under any
employee benefit plans, dividend re-investment plans, or direct access plans,
(ii) as a result of a reclassification of the Guarantor's capital stock or the
exchange or conversion of one class or series of the Guarantor's capital stock
for another class or series of the Guarantor's capital stock or, (iii) the
purchase of fractional interests in shares of the Guarantor's capital stock
pursuant to the conversion or exchange provisions of such capital stock of the
Guarantor or the security being converted or exchanged, (iv) dividends or
distributions in options, warrants, or rights to subscribe for or purchase
common stock of the Guarantor, or (v) any declaration of a dividend in
connection with the implementation of a shareholders' rights plan, or the
issuance of shares under any such plan in the future, or the redemption or
repurchase of any such rights pursuant thereto) or make any guarantee payments
with respect to the foregoing or (b) the Guarantor shall not make any payment of
interest, principal or premium, if any, on or repay, repurchase or redeem any
debt securities (including guarantees) issued by the Guarantor which rank pari
passu with or junior to the Debentures.

SECTION 6.2 Ranking

     This Preferred Securities Guarantee will constitute an unsecured obligation
of the Guarantor and will rank (i) subordinate and junior in right of payment to
all other liabilities of the Guarantor, (ii) pari passu with the most senior
preferred or preference stock now or hereafter issued by the Guarantor and with
any guarantee now or hereafter entered into by the Guarantor in respect of any
Preferred or preference stock of any Affiliate of the Guarantor, and (iii)
senior to the Guarantor's common stock.

                                   ARTICLE VII

                                   TERMINATION

SECTION 7.1 Termination

     This Preferred Securities Guarantee shall terminate upon (i) full payment
of the Redemption Price of all Preferred Securities, (ii) upon the distribution
of the Debentures to the Holders of all of the Preferred Securities or (iii)
upon full payment of the amounts payable in accordance with the Declaration upon
liquidation of the Issuer. Notwithstanding the foregoing, this Preferred
Securities Guarantee will continue to be effective or will be reinstated, as the
case
<PAGE>

                                                                              16

may be, if at any time any Holder of Preferred Securities must restore payment
of any sums paid under the Preferred Securities or under this Preferred
Securities Guarantee.

                                  ARTICLE VIII

                                 INDEMNIFICATION

SECTION 8.1 Exculpation

     (a) No Indemnified Person shall be liable, responsible or accountable in
damages or otherwise to the Guarantor or any Covered Person for any loss, damage
or claim incurred by reason of any act or omission performed or omitted by such
Indemnified Person in good faith in accordance with this Preferred Securities
Guarantee and in a manner that such Indemnified Person reasonably believed to be
within the scope of the authority conferred on such Indemnified Person by this
Preferred Securities Guarantee or by law, except that an Indemnified Person
shall be liable for any such loss, damage or claim incurred by reason of such
Indemnified Person's negligence or willful misconduct with respect to such acts
or omissions.

     (b) An Indemnified Person shall be fully protected in relying in good faith
upon the records of the Guarantor and upon such information, opinions, reports
or statements presented to the Guarantor by any Person as to matters the
Indemnified Person reasonably believes are within such other Person's
professional or expert competence and who has been selected with reasonable care
by or on behalf of the Guarantor, including information, opinions, reports or
statements as to the value and amount of the assets, liabilities, profits,
losses, or any other facts pertinent to the existence and amount of assets from
which Distributions to Holders of Preferred Securities might properly be paid.

SECTION 8.2 Indemnification

     The Guarantor agrees to indemnify each Indemnified Person for, and to hold
each Indemnified Person harmless against, any loss, liability or expense
incurred without negligence or bad faith on its part, arising out of or in
connection with the acceptance or administration of the trust or trusts
hereunder, including the costs and expenses (including reasonable legal fees and
expenses) of defending itself against, or investigating, any claim or liability
in connection with the exercise or performance of any of its powers or duties
hereunder. The obligation to indemnify as set forth in this Section 8.2 shall
survive the termination of this Preferred Securities Guarantee and the
resignation or removal of the Preferred Guarantee Trustee.

SECTION 8.3 Compensation.

     The Guarantor agrees to pay to the Preferred Guarantee Trustee from time to
time reasonable compensation, as mutually agreed to by the Guarantor and the
Preferred Guarantee Trustee, for all services rendered by it hereunder (which
compensation shall not be limited by any provision of law in regard to the
compensation of a trustee of an express trust).
<PAGE>

                                                                              17

                                   ARTICLE IX

                                  MISCELLANEOUS

SECTION 9.1 Successors and Assigns

     All guarantees and agreements contained in this Preferred Securities
Guarantee shall bind the successors, assigns, receivers, trustees and
representatives of the Guarantor and shall inure to the benefit of the Holders
of the Preferred Securities then outstanding. Except in connection with any
merger or consolidation of the Guarantor with or into another entity or any
sale, transfer or lease of the Guarantor's assets to another entity, in each
case, to the extent permitted under the Indenture, the Guarantor may not assign
its rights or delegate its obligations under this Guarantee.

SECTION 9.2 Amendments

     Except with respect to any changes that do not materially adversely affect
the rights of Holders (in which case no consent of Holders will be required),
this Preferred Securities Guarantee may only be amended with the prior approval
of the Guarantor, the Preferred Securities Guarantee Trustee and the Holders of
at least a Majority in liquidation amount (including the stated amount that
would be paid on redemption, liquidation or otherwise, plus accrued and unpaid
Distributions to the date upon which the voting percentages are determined) of
all the outstanding Preferred Securities. The provisions of Section 11.2 of the
Declaration with respect to meetings of Holders of the Securities apply to the
giving of such approval.

SECTION 9.3 Notices

     All notices provided for in this Preferred Securities Guarantee shall be in
writing, duly signed by the party giving such notice, and shall be delivered,
telecopied or mailed by registered or certified mail, as follows:

          (a) if given to the Preferred Guarantee Trustee, at the Preferred
Guarantee Trustee's mailing address set forth below (or such other address as
the Preferred Guarantee Trustee may give notice of to the Holders of the
Preferred Securities):

                      Bankers Trust Company
                      Corporate Trust and Agency Services
                      Four Albany Street, 4th Floor
                      New York, NY 10006
                      Attention: _____________

          (b) if given to the Guarantor, at the Guarantor's mailing address set
forth below (or such other address as the Guarantor may give notice of to the
Holders of the Preferred Securities):

                      Sunoco, Inc.
                      Ten Penn Center
                      1801 Market Street
                      Philadelphia, PA 19103
                      Attention: ______________

          (c) if given to any Holder of Preferred Securities, at the address set
forth on the books and records of the Issuer.
<PAGE>

                                                                              18

     All such notices shall be deemed to have been given when received in
person, telecopied with receipt confirmed, or mailed by first class mail,
postage prepaid except that if a notice or other document is refused delivery or
cannot be delivered because of a changed address of which no notice was given,
such notice or other document shall be deemed to have been delivered on the date
of such refusal or inability to deliver.

SECTION 9.4 Benefit

     This Preferred Securities Guarantee is solely for the benefit of the
Holders of the Preferred Securities and, subject to Section 3.1(a), is not
separately transferable from the Preferred Securities.

SECTION 9.5 Governing Law

     THIS PREFERRED SECURITIES GUARANTEE SHALL BE GOVERNED BY, AND CONSTRUED AND
INTERPRETED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

SECTION 9.6 Counterparts

     This Preferred Securities Guarantee may be executed in counterparts, each
of which shall be an original; but such counterparts together shall constitute
one and the same instrument.
<PAGE>

                                                                              19

     THIS PREFERRED SECURITIES GUARANTEE is executed as of the day and year
first above written.

                                 Sunoco, Inc.
                                 as Guarantor


                                 By:
                                    ----------------------------------
                                    Name:
                                    Title:


                                 Bankers Trust Company
                                 as Preferred Guarantee Trustee


                                 By:
                                    ----------------------------------
                                    Name:
                                    Title: