<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-11-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001012019</issuerCik>
        <issuerName>RUSH ENTERPRISES INC \TX\</issuerName>
        <issuerTradingSymbol>RUSHB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001418745</rptOwnerCik>
            <rptOwnerName>Teton Capital Partners LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>500 WEST 5TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1110</rptOwnerStreet2>
            <rptOwnerCity>AUSTIN</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78701</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001426749</rptOwnerCik>
            <rptOwnerName>Ancient Art, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>500 WEST 5TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1110</rptOwnerStreet2>
            <rptOwnerCity>AUSTIN</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78701</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001502494</rptOwnerCik>
            <rptOwnerName>Whitney, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>500 WEST 5TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1110</rptOwnerStreet2>
            <rptOwnerCity>AUSTIN</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78701</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001502493</rptOwnerCik>
            <rptOwnerName>Trango II, L.L.C.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>500 WEST 5TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1110</rptOwnerStreet2>
            <rptOwnerCity>AUSTIN</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78701</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001119365</rptOwnerCik>
            <rptOwnerName>LEE QUINCY J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>500 WEST 5TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1110</rptOwnerStreet2>
            <rptOwnerCity>AUSTIN</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78701</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock, $.01 Par Value</value>
            </securityTitle>
            <transactionDate>
                <value>2015-11-30</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>57916</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.65</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1106460</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The filing of this Form 4 shall not be construed as an admission that Ancient Art, L.P. (&quot;Ancient Art&quot;), Whitney, L.P. (&quot;Whitney&quot;), Trango II, L.L.C., the general partner of both Ancient Art and Whitney, and Quincy J. Lee, the principal of Trango, is or was for the purposes of Section 16(a) of the Securities Exchange Act of 1934, as amended, or otherwise the beneficial owner of any of the Class B Common Stock, $.01 Par Value (the &quot;Common Stock&quot;), of Rush Enterprises, Inc. (the &quot;Issuer&quot;) purchased by Teton Capital Partners, L.P. (the &quot;Fund&quot;).  Pursuant to Rule 16a-1,  Ancient Art, Whitney, Trango and Mr. Lee disclaim such beneficial ownership except to the extent of its or his spective pecuniary interest therein.</footnote>
        <footnote id="F2">The Fund, for which Ancient Art is the investment manager and Whitney is the general partner, holds 1,106,460 shares of Common Stock of the Issuer.  Trango is the general partner of both Ancient Art and Whitney.  Quincy J. Lee reports the Common Stock held indirectly by Ancient Art, Whitney and Trango because, as the principal of Trango at the time of purchase, he controlled the disposition and voting of the securities.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Quincy J. Lee, manager of Trango II, L.L.C., general partner of Whitney, L.P., general partner of Teton Capital Partners, L.P.</signatureName>
        <signatureDate>2015-12-02</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Quincy J. Lee, manager of Trango II, L.L.C., general partner of Ancient Art, L.P.</signatureName>
        <signatureDate>2015-12-02</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Quincy J. Lee, manager of Trango II, L.L.C., general partner of Whitney, L.P.</signatureName>
        <signatureDate>2015-12-02</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Quincy J. Lee, manager of Trango II, L.L.C.</signatureName>
        <signatureDate>2015-12-02</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Quincy J. Lee</signatureName>
        <signatureDate>2015-12-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
