-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 NjwIAuOBtx11zRNr7CoZB1y8P9j+7LsQEVfeyQS+x710IBqKSkBh3+Ywp5Vr79ix
 jnin+VIU77sFQ8wydADMog==

<SEC-DOCUMENT>0000095304-06-000007.txt : 20060120
<SEC-HEADER>0000095304-06-000007.hdr.sgml : 20060120
<ACCEPTANCE-DATETIME>20060120121102
ACCESSION NUMBER:		0000095304-06-000007
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20051231
FILED AS OF DATE:		20060120
DATE AS OF CHANGE:		20060120

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KROTT JOSEPH P
		CENTRAL INDEX KEY:			0001174598

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-06841
		FILM NUMBER:		06539978

	BUSINESS ADDRESS:	
		STREET 1:		1801 MARKET STREET
		CITY:			PHILADELPHIA
		STATE:			PA
		ZIP:			19103-1699

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SUNOCO INC
		CENTRAL INDEX KEY:			0000095304
		STANDARD INDUSTRIAL CLASSIFICATION:	PETROLEUM REFINING [2911]
		IRS NUMBER:				231743282
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		TEN PENN CENTER
		STREET 2:		1801 MARKET ST
		CITY:			PHILADELPHIA
		STATE:			PA
		ZIP:			19103-1699
		BUSINESS PHONE:		2159773000

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SUN CO INC
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SUN OIL CO
		DATE OF NAME CHANGE:	19760608
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2005-12-31</periodOfReport>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000095304</issuerCik>
        <issuerName>SUNOCO INC</issuerName>
        <issuerTradingSymbol>SUN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001174598</rptOwnerCik>
            <rptOwnerName>KROTT JOSEPH P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1735 MARKET STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PHILADELPHIA</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>19103-7583</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Comptroller</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4840</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2005-12-30</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>59</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7321</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>ESOP Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">On August 1, 2005, the common stock of Sunoco, Inc. split 2-for-1, resulting in a doubling of the shares beneficially owned (direct or indirect) by the reporting person.</footnote>
        <footnote id="F3">Price ranged from $72.70 to $125.73 during fiscal year 2005.  This information is supplied by the Plan Administrator for the Sunoco, Inc. Capital Accumulation Plan.</footnote>
        <footnote id="F2">Routine, periodic acquisition of share equivalents pursuant to the Sunoco, Inc. Capital Accumulation Plan in transactions exempt under Rule 16(b).  This information is supplied by the Plan Administrator.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>John J. DiRocco, Jr., Attorney-in-fact for Joseph P. Krott</signatureName>
        <signatureDate>2006-01-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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