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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-07-17</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000808450</issuerCik>
        <issuerName>NAVISTAR INTERNATIONAL CORP</issuerName>
        <issuerTradingSymbol>NAV</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001697835</rptOwnerCik>
            <rptOwnerName>Volkswagen Truck &amp; Bus GmbH</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BRAWO PARK</rptOwnerStreet1>
            <rptOwnerStreet2>WILLY-BRANDT-PLATZ 19</rptOwnerStreet2>
            <rptOwnerCity>BRAUNSCHWEIG</rptOwnerCity>
            <rptOwnerState>2M</rptOwnerState>
            <rptOwnerZipCode>38102</rptOwnerZipCode>
            <rptOwnerStateDescription>GERMANY</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001111708</rptOwnerCik>
            <rptOwnerName>VOLKSWAGEN AG</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>VOLKSWAGEN AG</rptOwnerStreet1>
            <rptOwnerStreet2>BERLINER RING 2</rptOwnerStreet2>
            <rptOwnerCity>WOLFSBURG, LOWER SAXONY</rptOwnerCity>
            <rptOwnerState>2M</rptOwnerState>
            <rptOwnerZipCode>38440</rptOwnerZipCode>
            <rptOwnerStateDescription>GERMANY</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.10 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2017-07-17</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2017-07-18</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>43501</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>29.25</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16285513</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.10 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2017-07-18</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2017-07-19</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>52625</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>29.13</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16338138</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.10 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2017-07-19</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2017-07-20</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>61900</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>29.18</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16400038</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This statement is being filed jointly by Volkswagen Truck &amp; Bus GmbH (&quot;VW T&amp;B&quot;) and Volkswagen AG (&quot;Volkswagen&quot; and together with VW T&amp;B, the &quot;Reporting Persons&quot;). VW T&amp;B is a wholly-owned subsidiary of Volkswagen and is the direct holder of the securities reported on this statement.</footnote>
        <footnote id="F2">Shares of Navistar International Corporation common stock, par value $0.10 per share, were purchased by VW T&amp;B, a wholly owned subsidiary of Volkswagen, in open market transactions.</footnote>
        <footnote id="F3">The purchases reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by VW T&amp;B on June 16, 2017.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Andreea Costa, Attorney in fact for Volkswagen Truck &amp; Bus GmbH /s/ Andreea Costa</signatureName>
        <signatureDate>2017-07-20</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Frederik Fragemann, Attorney in fact for Volkswagen Truck &amp; Bus GmbH /s/ Frederik Fragemann</signatureName>
        <signatureDate>2017-07-20</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Andreea Costa, Attorney in fact for Volkswagen AG /s/ Andreea Costa</signatureName>
        <signatureDate>2017-07-20</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Frederik Fragemann, Attorney in fact for Volkswagen AG /s/ Frederik Fragemann</signatureName>
        <signatureDate>2017-07-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
