-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 3iB+mKNSETxIsD0EIDgjPw==

<SEC-DOCUMENT>0001015033-05-000002.txt : 20050301
<SEC-HEADER>0001015033-05-000002.hdr.sgml : 20050301
<ACCEPTANCE-DATETIME>20050301110224
ACCESSION NUMBER:		0001015033-05-000002
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050228
FILED AS OF DATE:		20050301
DATE AS OF CHANGE:		20050301

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LUBRIZOL CORP
		CENTRAL INDEX KEY:			0000060751
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL ORGANIC CHEMICALS [2860]
		IRS NUMBER:				340367600
		STATE OF INCORPORATION:			OH
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		29400 LAKELAND BLVD
		CITY:			WICKLIFFE
		STATE:			OH
		ZIP:			44092
		BUSINESS PHONE:		2169434200

	MAIL ADDRESS:	
		STREET 1:		29400 LAKELAND BLVD
		CITY:			WICKLIFFE
		STATE:			OH
		ZIP:			44092

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SOMERS DANIEL E
		CENTRAL INDEX KEY:			0001082950

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-05263
		FILM NUMBER:		05648472

	BUSINESS ADDRESS:	
		STREET 1:		C/O LUBRIZOL CORP
		STREET 2:		29400 LAKELAND BLVD
		CITY:			WICKLIFFE
		STATE:			OH
		ZIP:			44092
		BUSINESS PHONE:		4409434200

	MAIL ADDRESS:	
		STREET 1:		1157 CENTURY DR
		CITY:			LOUISVILLE
		STATE:			CO
		ZIP:			80027
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-02-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000060751</issuerCik>
        <issuerName>LUBRIZOL CORP</issuerName>
        <issuerTradingSymbol>LZ</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001082950</rptOwnerCik>
            <rptOwnerName>SOMERS DANIEL E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>THE LUBRIZOL CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>29400 LAKELAND BOULEVARD</rptOwnerStreet2>
            <rptOwnerCity>WICKLIFFE</rptOwnerCity>
            <rptOwnerState>OH</rptOwnerState>
            <rptOwnerZipCode>44092</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2005-02-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>26.8438</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10580.7191</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Director Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>26.8438</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-02-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>1999-04-26</value>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2009-04-26</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Reflects acquisitions pursuant to a dividend reinvestment plan exempt under Rule 16a-11.</footnote>
        <footnote id="F2">Options vest 50% one year after grant date, 75% two years after grant date and 100% three years after grant date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Daniel E. Somers by Andrea A. Zwegat</signatureName>
        <signatureDate>2005-03-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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