<PAGE>
      AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON MAY 16, 1997
                                                      REGISTRATION NO. 333-
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------
 
                                    FORM S-8
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                            ------------------------
 
                                  TENNECO INC.
 
             (Exact name of registrant as specified in its charter)
 
<TABLE>
<S>                              <C>
           DELAWARE                  ISSUER:
                                    76-0515284
 (State or other jurisdiction        (I.R.S.
              of                     Employer
incorporation or organization)    Identification
                                       No.)
</TABLE>
 
                         1275 KING STREET
                     GREENWICH, CONNECTICUT               06831
             (Address of Principal Executive Offices)    (Zip Code)
 
                            ------------------------
 
                    TENNECO THRIFT PLAN FOR HOURLY EMPLOYEES
 
                            (Full Title of the Plan)
 
                                KARL A. STEWART
                          VICE PRESIDENT AND SECRETARY
                                  TENNECO INC.
                                1275 KING STREET
                          GREENWICH, CONNECTICUT 06831
 
                    (Name and address of agent for service)
 
                           TELEPHONE: (203) 863-1000
 
         (Telephone number, including area code, of agent for service)
 
                            ------------------------
 
                        CALCULATION OF REGISTRATION FEE
 
<TABLE>
<CAPTION>
                                                            PROPOSED MAXIMUM    PROPOSED MAXIMUM
         TITLE OF SECURITIES              AMOUNT TO BE       OFFERING PRICE        AGGREGATE           AMOUNT OF
          TO BE REGISTERED                 REGISTERED          PER SHARE*       OFFERING PRICE*    REGISTRATION FEE*
<S>                                    <C>                 <C>                 <C>                 <C>
Common Stock, par value $.01 per
  share (including associated
  rights)............................    64,000 shares           $41.94            $2,684,160             $814
</TABLE>
 
* Calculated pursuant to Rule 457(c) under the Securities Act of 1933, as
  amended (the "Securities Act"), based on the average of the high and low
  prices of the Company's Common Stock as reported on the New York Stock
  Exchange on May 9, 1997.
 
                            ------------------------
 
    In addition, pursuant to Rule 416(c) under the Securities Act, this
Registration Statement also covers an indeterminate amount of interests to be
offered or sold pursuant to the employee benefit plan described herein.
 
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
<PAGE>
    This Registration Statement covers 64,000 shares of Common Stock, par value
$.01 per share, and the associated preferred share purchase rights attached
thereto (the "Common Stock") of Tenneco Inc. (the "Company") which may be
offered or sold from time to time under the Tenneco Thrift Plan for Hourly
Employees, giving effect to the merger (the "Merger") of the Tenneco Packaging
401(k) Savings Plan with and into such Thrift Plan (the "Plan"). This
Registration Statement also covers an indeterminate amount of interests to be
offered or sold from time to time under the Plan. The Merger is expected to take
place on or about August 1, 1997.
 
                                     PART I
 
              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS
 
ITEM 1.  PLAN INFORMATION.
 
    Not required to be included herewith.
 
ITEM 2.  REGISTRANT INFORMATION AND EMPLOYEE PLAN ANNUAL INFORMATION.
 
    Not required to be included herewith.
 
                                    PART II
 
               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
 
ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.
 
    The following documents filed by the Company with the Securities and
Exchange Commission (the "Commission") pursuant to the Securities and Exchange
Act of 1934, as amended (the "Exchange Act"), are hereby incorporated by
reference into this Registration Statement:
 
    (a) The Company's Annual Report on Form 10-K for the year ended December 31,
       1996;
 
    (b) The Company's Current Reports on Form 8-K dated March 27, 1997, April
       25, 1997 and April 29, 1997 and its Current Report on Form 8-K/A dated
       February 24, 1997;
 
    (c) The Company's Quarterly Report on Form 10-Q for the quarter ended March
       31, 1997; and
 
    (d) The description of the Common Stock included in the Company's
       Registration Statement on Form 10, Registration No. 1-12387, originally
       filed with the Commission on October 30, 1996, as amended.
 
    In addition to the foregoing, all documents subsequently filed by the
Company or the Plan pursuant to Sections 13(a), 13(c), 14 or 15(d) of the
Exchange Act, prior to the filing of a post-effective amendment which indicates
that all securities registered hereunder have been issued or which deregisters
all securities offered then remaining unsold, shall be deemed incorporated by
reference in this Registration Statement and to be a part hereof from the date
of the filing of such documents. Any statement, including financial statements,
contained in a document incorporated or deemed to be incorporated by reference
herein shall be deemed to be modified or superseded for purposes of this
Registration Statement to the extent that a statement contained herein or in any
other subsequently filed document which also is or is deemed to be incorporated
by reference herein modifies or supersedes such statement. Any such statement so
modified or superseded shall not be deemed, except as so modified or superseded,
to constitute a part of this Registration Statement.
 
ITEM 4.  DESCRIPTION OF SECURITIES.
 
    Not applicable.
 
                                       1
<PAGE>
ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.
 
    Certain legal matters regarding the Common Stock offered hereby will be
passed upon for the Company by Theodore R. Tetzlaff, General Counsel of the
Company. As of April 30, 1997, Mr. Tetzlaff beneficially owned 87,623 shares of
Common Stock (including options to purchase 44,118 shares of Common Stock, which
options were either exercisable as of such date or exercisable within 60 days of
such date).
 
ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.
 
    Section 145 of the Delaware General Corporation Law ("DGCL") gives Delaware
corporations broad powers to indemnify their present and former directors and
officers and those of affiliated corporations against expenses incurred in the
defense of any lawsuit to which they are made parties by reason of being or
having been such directors or officers, subject to specified conditions and
exclusions, allows the advancement of costs of defending against litigation, and
permits the Company to purchase insurance on behalf of directors, officers,
employees, and agents. Such indemnification is not exclusive of any other rights
to which those indemnified may be entitled under any by-laws, agreement, vote of
stockholders or otherwise.
 
    The Restated Certificate of Incorporation of the Company (the "Certificate")
provides that a director of the Company will not be liable to the Company or its
stockholders for monetary damages for breach of fiduciary duty as a director,
except to the extent such exemption from liability or limitation thereof is not
permitted under the DGCL as the same exists or may thereafter be amended. Based
on the DGCL as presently in effect, a director of the Company will not be
personally liable to the Company or its stockholders for monetary damages for
breach of fiduciary duty as a director, except for liability (i) for any breach
of the director's duty of loyalty to the Company or its stockholders, (ii) for
acts or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) under Section 174 of the DGCL, which concerns
unlawful payments of dividends, stock purchases or redemptions, or (iv) for any
transactions from which the director derived an improper personal benefit.
 
    While the Certificate provides directors with protection from awards for
monetary damages for breaches of their duty of care, it does not eliminate such
duty. Accordingly, the Certificate has no effect on the availability of
equitable remedies such as an injunction or rescission based on a director's
breach of his or her duty of care. The provisions of the Certificate described
above apply to an officer of the Company only if he or she is a director of the
Company and is acting in his or her capacity as director, and do not apply to
officers of the Company who are not directors.
 
    The Amended and Restated By-laws of the Company (the "By-laws") provide that
the Company will indemnify and hold harmless, to the fullest extent permitted by
applicable law as it presently exists or may thereafter be amended, any person
(an "Indemnitee") who was or is made or is threatened to be made a party or is
otherwise involved in any action, suit or proceeding, whether civil, criminal,
administrative or investigative (a "proceeding"), by reason of the fact that he,
or a person for whom he is the legal representative, is or was a director or
officer of the Company or, while a director or officer of the Company, is or was
serving at the request of the Company as a director, officer, employee or agent
of another Company or of a partnership, joint venture, trust, enterprise or
nonprofit entity, including service with respect to employee benefit plans,
against all liability and loss suffered and expenses (including attorneys' fees)
reasonably incurred by such Indemnitee. The By-laws also provide that,
notwithstanding the foregoing, but except as described in the second following
paragraph, the Company is required to indemnify an Indemnitee in connection with
a proceeding (or part thereof) commenced by such Indemnitee only if the
commencement of such proceeding (or part thereof) by the Indemnitee was
authorized by the Company's Board of Directors.
 
    The By-laws further provide that the Company will pay the expenses
(including attorneys' fees) incurred by an Indemnitee in defending any
proceeding in advance of its final disposition; provided,
 
                                       2
<PAGE>
however, that, to the extent required by law, such payment of expenses in
advance of the final disposition of the proceeding will be made only upon
receipt of an undertaking by the Indemnitee to repay all amounts advanced if it
should be ultimately determined that the Indemnitee is not entitled to be
indemnified under the relevant section of the By-laws or otherwise.
 
    Pursuant to the By-laws, if a claim for indemnification or payment of
expenses thereunder is not paid in full within 30 days after a written claim
therefor by the Indemnitee has been received by the Company, the Indemnitee may
file suit to recover the unpaid amount of such claim and, if successful in whole
or in part, will be entitled to be paid the expense of prosecuting such claim.
The By-laws provide that, in any such action, the Company will have the burden
of proving that the Indemnitee is not entitled to the requested indemnification
or payment of expenses under applicable law.
 
    The By-laws also provide (i) that the rights conferred on any Indemnitee
thereby are not exclusive of any other rights which such Indemnitee may have or
thereafter acquire under any statute, provision of the Certificate, the By-laws,
agreement, vote of stockholders or disinterested directors or otherwise, (ii)
that the Company's obligation, if any, to indemnify or to advance expenses to
any Indemnitee who was or is serving at its request as a director, officer,
employee or agent of another Company, partnership, joint venture, trust,
enterprise or nonprofit entity will be reduced by any amount such Indemnitee may
collect as indemnification or advancement of expenses from such other Company,
partnership, joint venture, trust, enterprise or nonprofit enterprise and (iii)
that any repeal or modification of the relevant provisions of the By-laws will
not adversely affect any right or protection thereunder of any Indemnitee in
respect of any act or omission occurring prior to the time of such repeal or
modification.
 
    The By-laws also expressly state that the provisions thereof will not limit
the right of the Company, to the extent and in the manner permitted by law, to
indemnify and to advance expenses to persons other than Indemnitees when and as
authorized by appropriate corporate action.
 
    The Company has purchased insurance which purports to insure the Company
against certain costs of indemnification which may be incurred by it pursuant to
the foregoing provisions, and to insure the officers and directors of the
Company, and of its subsidiary companies, against certain liabilities incurred
by them in the discharge of their function as such officers and directors except
for liabilities resulting from their own malfeasance.
 
ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.
 
    Not applicable.
 
                                       3
<PAGE>
ITEM 8.  EXHIBITS.
 
    The following exhibits are filed as part of this Registration Statement:
 
<TABLE>
<C>        <C>        <S>
     *4.1         --  Restated Certificate of Incorporation of the Company.
 
     *4.2         --  Amended and Restated By-laws of the Company.
 
     *4.3         --  Rights Agreement, dated as of December 11, 1996, by and between Tenneco Inc.
                      (formerly New Tenneco Inc.) and First Chicago Trust Company of New York, as
                      Rights Agent.
 
    **4.4         --  Form of Specimen Stock Certificate of Tenneco Inc. Common Stock.
 
      5.1         --  Opinion of Theodore R. Tetzlaff, Esq. as to the legality of the Common Stock
                      being registered.
 
      15          --  None.
 
     23.1         --  Consent of Theodore R. Tetzlaff, Esq. (included in Exhibit 5).
 
     23.2         --  Consent of Arthur Andersen LLP.
 
     24.1         --  Powers of Attorney of the following Directors of the Company: Mark Andrews, W.
                      Michael Blumenthal, M. Kathryn Eickhoff, Peter T. Flawn, Henry U. Harris, Jr.,
                      Belton K. Johnson, John B. McCoy, Sir David Plastow, William L. Weiss and
                      Clifton R. Wharton, Jr.
 
      99          --  None.
</TABLE>
 
------------------------
 
 * Incorporated by reference to the Company's Annual Report on Form 10-K for the
   year ended December 31, 1996.
 
** Incorporated by reference to the Company's Registration Statement on Form 10,
   File No. 1-12387, originally filed with the Commission on October 30, 1996,
   as amended.
 
    The Company will submit or has submitted the Plan, and hereby undertakes to
submit any amendments thereto, to the Internal Revenue Service in a timely
manner and has made or will make all changes required by the Internal Revenue
Service in order to qualify said Plan.
 
ITEM 9.  UNDERTAKINGS.
 
A.  SUBSEQUENT DISCLOSURE.
 
    The Company hereby undertakes:
 
    (1) To file, during any period in which offers or sales are being made of
       the securities registered hereby, a post-effective amendment to this
       Registration Statement:
 
            (i) To include any prospectus required by section 10(a)(3) of the
       Securities Act;
 
            (ii) To reflect in the prospectus any facts or events arising after
       the effective date of this Registration Statement (or the most recent
       post-effective amendment thereof) which, individually or in the
       aggregate, represent a fundamental change in the information set forth in
       this Registration Statement;
 
           (iii) To include any material information with respect to the plan of
       distribution not previously disclosed in this Registration Statement or
       any material change to such information in this Registration Statement;
 
Provided, however, that the undertakings set forth in paragraphs (i) and (ii)
above do not apply if the information required to be included in a
post-effective amendment by those paragraphs is contained in
 
                                       4
<PAGE>
periodic reports filed with or furnished to the Commission by the Company,
pursuant to Section 13 or Section 15(d) of the Exchange Act that are
incorporated by reference in this Registration Statement.
 
    (2) That, for the purpose of determining any liability under the Securities
       Act, each such post-effective amendment shall be deemed to be a new
       registration statement relating to the securities offered therein, and
       the offering of such securities at that time shall be deemed to be the
       initial bona fide offering thereof.
 
    (3) To remove from registration by means of a post-effective amendment any
       of the securities being registered which remain unsold at the termination
       of the offering.
 
B.  INCORPORATION BY REFERENCE.
 
    The Company hereby undertakes that, for purposes of determining any
liability under the Securities Act, each filing of the Company's annual report
pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where
applicable, each filing of an employee benefit plan's annual report pursuant to
Section 15(d) of the Exchange Act) that is incorporated by reference in this
Registration Statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.
 
C.  COMMISSION POSITION ON INDEMNIFICATION.
 
    The Company hereby undertakes that, insofar as indemnification for
liabilities arising under the Securities Act may be permitted to directors,
officers and controlling persons of the Company pursuant to the foregoing
provisions, or otherwise, the Company has been advised that in the opinion of
the Commission such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the Company
of expenses incurred or paid by a director, officer or controlling person of the
Company in the successful defense of any action, suit or proceeding) is asserted
by such director, officer or controlling person in connection with the
securities being registered, the Company will, unless in the opinion of its
counsel the matter has been settled by controlling precedent, submit to a court
of appropriate jurisdiction the question whether such indemnification by it is
against public policy as expressed in the Securities Act and will be governed by
the final adjudication of such issue.
 
                                       5
<PAGE>
                                   SIGNATURES
 
    THE REGISTRANT.  Pursuant to the requirements of the Securities Act of 1933,
the Registrant certifies that it has reasonable grounds to believe that it meets
all of the requirements for filing on Form S-8 and has duly caused this
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Greenwich, State of Connecticut, on this 16th
day of May, 1997.
 
                                          TENNECO INC.
 
                                          By          /s/ DANA G. MEAD
 
                                          --------------------------------------
 
                                                       Dana G. Mead
                                           CHAIRMAN AND CHIEF EXECUTIVE OFFICER
 
    Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the date indicated.
 
            SIGNATURE                           TITLE                  DATE
----------------------------------  ------------------------------  -----------
 
         /s/ DANA G. MEAD
----------------------------------  Principal Executive Officer       May 16,
           Dana G. Mead               and Director                     1997
 
      /s/ ROBERT T. BLAKELY
----------------------------------  Principal Financial and           May 16,
        Robert T. Blakely             Accounting Officer               1997
 
Mark Andrews, W. Michael            Directors
Blumenthal, M. Kathryn Eickhoff,
Peter T. Flawn, Henry U. Harris,
Jr., Belton K. Johnson, John B.
McCoy, Sir David Plastow, William
L. Weiss, Clifton R. Wharton, Jr.
 
By      /s/ THEODORE R.
TETZLAFF
----------------------------------                                    May 16,
            Theodore R.                                                1997
Tetzlaff
               ATTORNEY-IN-FACT
<PAGE>
                                   SIGNATURES
 
    THE PLAN.  Pursuant to the requirements of the Securities Act of 1933, the
Committee appointed under the Tenneco Thrift Plan for Hourly Employees has duly
caused this Registration Statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of Greenwich, State of
Connecticut, on this 16th day of May, 1997.
 
                                          TENNECO THRIFT PLAN FOR HOURLY
                                          EMPLOYEES
 
                                          By          /s/ DANA G. MEAD
 
                                            ------------------------------------
 
                                                        Dana G. Mead
                                                  CHAIRMAN OF TENNECO INC.
                                                     BENEFITS COMMITTEE
<PAGE>
                                 EXHIBIT INDEX
 
<TABLE>
<CAPTION>
 EXHIBIT
  NUMBER                                                       DESCRIPTION
---------             ----------------------------------------------------------------------------------------------
<C>        <S>        <C>
     *4.1  --         Restated Certificate of Incorporation of the Company.
 
     *4.2  --         Amended and Restated By-laws of the Company.
 
     *4.3  --         Rights Agreement, dated as of December 11, 1996, by and between Tenneco Inc. (formerly New
                      Tenneco Inc.) and First Chicago Trust Company of New York, as Rights Agent.
 
    **4.4  --         Form of Specimen Stock Certificate of Tenneco Inc. Common Stock.
 
      5.1  --         Opinion of Theodore R. Tetzlaff, Esq. as to the legality of the Common Stock being registered.
 
      15   --         None.
 
     23.1  --         Consent of Theodore R. Tetzlaff, Esq. (included in Exhibit 5).
 
     23.2  --         Consent of Arthur Andersen LLP.
 
     24.1  --         Powers of Attorney of the following Directors of the Company: Mark Andrews, W. Michael
                      Blumenthal, M. Kathryn Eickhoff, Peter T. Flawn, Henry U. Harris, Jr., Belton K. Johnson, John
                      B. McCoy, Sir David Plastow, William L. Weiss and Clifton R. Wharton, Jr.
 
      99   --         None.
</TABLE>
 
------------------------
 
 * Incorporated by reference to the Company's Annual Report on Form 10-K for the
   year ended December 31, 1996.
 
** Incorporated by reference to the Company's Registration Statement on Form 10,
   File No. 1-12387, originally filed with the Commission on October 30, 1996,
   as amended.
[{"type": "S-8", "sequence": "1", "description": "S-8", "secsgml_size_bytes": 24279}]
{"company-data": {"conformed-name": "TENNECO INC /DE", "cik": "0001024725", "assigned-sic": "3523", "irs-number": "760515284", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-27279", "film-number": "97610486"}, "business-address": {"street1": "1275 KING STREET", "city": "GREENWICH", "state": "CT", "zip": "06831", "phone": "2038631000"}, "mail-address": {"street1": "1010 MILAM STREET", "street2": "ROOM T 2560B", "city": "HOUSTON", "state": "TX", "zip": "77002"}, "former-company": {"former-conformed-name": "NEW TENNECO INC", "date-changed": "19961011"}}
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON MAY 16, 1997
                                                      REGISTRATION NO. 333-
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------
 
                                    FORM S-8
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                            ------------------------
 
                                  TENNECO INC.
 
             (Exact name of registrant as specified in its charter)
DELAWARE                  ISSUER:
                                    76-0515284
 (State or other jurisdiction        (I.R.S.
              of                     Employer
incorporation or organization)    Identification
                                       No.)
1275 KING STREET
                     GREENWICH, CONNECTICUT               06831
             (Address of Principal Executive Offices)    (Zip Code)
 
                            ------------------------
 
                    TENNECO THRIFT PLAN FOR HOURLY EMPLOYEES
 
                            (Full Title of the Plan)
 
                                KARL A. STEWART
                          VICE PRESIDENT AND SECRETARY
                                  TENNECO INC.
                                1275 KING STREET
                          GREENWICH, CONNECTICUT 06831
 
                    (Name and address of agent for service)
 
                           TELEPHONE: (203) 863-1000
 
         (Telephone number, including area code, of agent for service)
 
                            ------------------------
 
                        CALCULATION OF REGISTRATION FEE
PROPOSED MAXIMUM    PROPOSED MAXIMUM
         TITLE OF SECURITIES              AMOUNT TO BE       OFFERING PRICE        AGGREGATE           AMOUNT OF
          TO BE REGISTERED                 REGISTERED          PER SHARE*       OFFERING PRICE*    REGISTRATION FEE*
Common Stock, par value $.01 per
  share (including associated
  rights)............................    64,000 shares           $41.94            $2,684,160             $814
* Calculated pursuant to Rule 457(c) under the Securities Act of 1933, as
  amended (the "Securities Act"), based on the average of the high and low
  prices of the Company's Common Stock as reported on the New York Stock
  Exchange on May 9, 1997.
 
                            ------------------------
 
    In addition, pursuant to Rule 416(c) under the Securities Act, this
Registration Statement also covers an indeterminate amount of interests to be
offered or sold pursuant to the employee benefit plan described herein.
 
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
This Registration Statement covers 64,000 shares of Common Stock, par value
$.01 per share, and the associated preferred share purchase rights attached
thereto (the "Common Stock") of Tenneco Inc. (the "Company") which may be
offered or sold from time to time under the Tenneco Thrift Plan for Hourly
Employees, giving effect to the merger (the "Merger") of the Tenneco Packaging
401(k) Savings Plan with and into such Thrift Plan (the "Plan"). This
Registration Statement also covers an indeterminate amount of interests to be
offered or sold from time to time under the Plan. The Merger is expected to take
place on or about August 1, 1997.
 
                                     PART I
 
              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS
 
ITEM 1.  PLAN INFORMATION.
 
    Not required to be included herewith.
 
ITEM 2.  REGISTRANT INFORMATION AND EMPLOYEE PLAN ANNUAL INFORMATION.
 
    Not required to be included herewith.
 
                                    PART II
 
               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
 
ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.
 
    The following documents filed by the Company with the Securities and
Exchange Commission (the "Commission") pursuant to the Securities and Exchange
Act of 1934, as amended (the "Exchange Act"), are hereby incorporated by
reference into this Registration Statement:
 
    (a) The Company's Annual Report on Form 10-K for the year ended December 31,
       1996;
 
    (b) The Company's Current Reports on Form 8-K dated March 27, 1997, April
       25, 1997 and April 29, 1997 and its Current Report on Form 8-K/A dated
       February 24, 1997;
 
    (c) The Company's Quarterly Report on Form 10-Q for the quarter ended March
       31, 1997; and
 
    (d) The description of the Common Stock included in the Company's
       Registration Statement on Form 10, Registration No. 1-12387, originally
       filed with the Commission on October 30, 1996, as amended.
 
    In addition to the foregoing, all documents subsequently filed by the
Company or the Plan pursuant to Sections 13(a), 13(c), 14 or 15(d) of the
Exchange Act, prior to the filing of a post-effective amendment which indicates
that all securities registered hereunder have been issued or which deregisters
all securities offered then remaining unsold, shall be deemed incorporated by
reference in this Registration Statement and to be a part hereof from the date
of the filing of such documents. Any statement, including financial statements,
contained in a document incorporated or deemed to be incorporated by reference
herein shall be deemed to be modified or superseded for purposes of this
Registration Statement to the extent that a statement contained herein or in any
other subsequently filed document which also is or is deemed to be incorporated
by reference herein modifies or supersedes such statement. Any such statement so
modified or superseded shall not be deemed, except as so modified or superseded,
to constitute a part of this Registration Statement.
 
ITEM 4.  DESCRIPTION OF SECURITIES.
 
    Not applicable.
 
                                       1
ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.
 
    Certain legal matters regarding the Common Stock offered hereby will be
passed upon for the Company by Theodore R. Tetzlaff, General Counsel of the
Company. As of April 30, 1997, Mr. Tetzlaff beneficially owned 87,623 shares of
Common Stock (including options to purchase 44,118 shares of Common Stock, which
options were either exercisable as of such date or exercisable within 60 days of
such date).
 
ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.
 
    Section 145 of the Delaware General Corporation Law ("DGCL") gives Delaware
corporations broad powers to indemnify their present and former directors and
officers and those of affiliated corporations against expenses incurred in the
defense of any lawsuit to which they are made parties by reason of being or
having been such directors or officers, subject to specified conditions and
exclusions, allows the advancement of costs of defending against litigation, and
permits the Company to purchase insurance on behalf of directors, officers,
employees, and agents. Such indemnification is not exclusive of any other rights
to which those indemnified may be entitled under any by-laws, agreement, vote of
stockholders or otherwise.
 
    The Restated Certificate of Incorporation of the Company (the "Certificate")
provides that a director of the Company will not be liable to the Company or its
stockholders for monetary damages for breach of fiduciary duty as a director,
except to the extent such exemption from liability or limitation thereof is not
permitted under the DGCL as the same exists or may thereafter be amended. Based
on the DGCL as presently in effect, a director of the Company will not be
personally liable to the Company or its stockholders for monetary damages for
breach of fiduciary duty as a director, except for liability (i) for any breach
of the director's duty of loyalty to the Company or its stockholders, (ii) for
acts or omissions not in good faith or which involve intentional misconduct or a
knowing violation of law, (iii) under Section 174 of the DGCL, which concerns
unlawful payments of dividends, stock purchases or redemptions, or (iv) for any
transactions from which the director derived an improper personal benefit.
 
    While the Certificate provides directors with protection from awards for
monetary damages for breaches of their duty of care, it does not eliminate such
duty. Accordingly, the Certificate has no effect on the availability of
equitable remedies such as an injunction or rescission based on a director's
breach of his or her duty of care. The provisions of the Certificate described
above apply to an officer of the Company only if he or she is a director of the
Company and is acting in his or her capacity as director, and do not apply to
officers of the Company who are not directors.
 
    The Amended and Restated By-laws of the Company (the "By-laws") provide that
the Company will indemnify and hold harmless, to the fullest extent permitted by
applicable law as it presently exists or may thereafter be amended, any person
(an "Indemnitee") who was or is made or is threatened to be made a party or is
otherwise involved in any action, suit or proceeding, whether civil, criminal,
administrative or investigative (a "proceeding"), by reason of the fact that he,
or a person for whom he is the legal representative, is or was a director or
officer of the Company or, while a director or officer of the Company, is or was
serving at the request of the Company as a director, officer, employee or agent
of another Company or of a partnership, joint venture, trust, enterprise or
nonprofit entity, including service with respect to employee benefit plans,
against all liability and loss suffered and expenses (including attorneys' fees)
reasonably incurred by such Indemnitee. The By-laws also provide that,
notwithstanding the foregoing, but except as described in the second following
paragraph, the Company is required to indemnify an Indemnitee in connection with
a proceeding (or part thereof) commenced by such Indemnitee only if the
commencement of such proceeding (or part thereof) by the Indemnitee was
authorized by the Company's Board of Directors.
 
    The By-laws further provide that the Company will pay the expenses
(including attorneys' fees) incurred by an Indemnitee in defending any
proceeding in advance of its final disposition; provided,
 
                                       2
however, that, to the extent required by law, such payment of expenses in
advance of the final disposition of the proceeding will be made only upon
receipt of an undertaking by the Indemnitee to repay all amounts advanced if it
should be ultimately determined that the Indemnitee is not entitled to be
indemnified under the relevant section of the By-laws or otherwise.
 
    Pursuant to the By-laws, if a claim for indemnification or payment of
expenses thereunder is not paid in full within 30 days after a written claim
therefor by the Indemnitee has been received by the Company, the Indemnitee may
file suit to recover the unpaid amount of such claim and, if successful in whole
or in part, will be entitled to be paid the expense of prosecuting such claim.
The By-laws provide that, in any such action, the Company will have the burden
of proving that the Indemnitee is not entitled to the requested indemnification
or payment of expenses under applicable law.
 
    The By-laws also provide (i) that the rights conferred on any Indemnitee
thereby are not exclusive of any other rights which such Indemnitee may have or
thereafter acquire under any statute, provision of the Certificate, the By-laws,
agreement, vote of stockholders or disinterested directors or otherwise, (ii)
that the Company's obligation, if any, to indemnify or to advance expenses to
any Indemnitee who was or is serving at its request as a director, officer,
employee or agent of another Company, partnership, joint venture, trust,
enterprise or nonprofit entity will be reduced by any amount such Indemnitee may
collect as indemnification or advancement of expenses from such other Company,
partnership, joint venture, trust, enterprise or nonprofit enterprise and (iii)
that any repeal or modification of the relevant provisions of the By-laws will
not adversely affect any right or protection thereunder of any Indemnitee in
respect of any act or omission occurring prior to the time of such repeal or
modification.
 
    The By-laws also expressly state that the provisions thereof will not limit
the right of the Company, to the extent and in the manner permitted by law, to
indemnify and to advance expenses to persons other than Indemnitees when and as
authorized by appropriate corporate action.
 
    The Company has purchased insurance which purports to insure the Company
against certain costs of indemnification which may be incurred by it pursuant to
the foregoing provisions, and to insure the officers and directors of the
Company, and of its subsidiary companies, against certain liabilities incurred
by them in the discharge of their function as such officers and directors except
for liabilities resulting from their own malfeasance.
 
ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.
 
    Not applicable.
 
                                       3
ITEM 8.  EXHIBITS.
 
    The following exhibits are filed as part of this Registration Statement:
*4.1         --  Restated Certificate of Incorporation of the Company.
 
     *4.2         --  Amended and Restated By-laws of the Company.
 
     *4.3         --  Rights Agreement, dated as of December 11, 1996, by and between Tenneco Inc.
                      (formerly New Tenneco Inc.) and First Chicago Trust Company of New York, as
                      Rights Agent.
 
    **4.4         --  Form of Specimen Stock Certificate of Tenneco Inc. Common Stock.
 
      5.1         --  Opinion of Theodore R. Tetzlaff, Esq. as to the legality of the Common Stock
                      being registered.
 
      15          --  None.
 
     23.1         --  Consent of Theodore R. Tetzlaff, Esq. (included in Exhibit 5).
 
     23.2         --  Consent of Arthur Andersen LLP.
 
     24.1         --  Powers of Attorney of the following Directors of the Company: Mark Andrews, W.
                      Michael Blumenthal, M. Kathryn Eickhoff, Peter T. Flawn, Henry U. Harris, Jr.,
                      Belton K. Johnson, John B. McCoy, Sir David Plastow, William L. Weiss and
                      Clifton R. Wharton, Jr.
 
      99          --  None.
------------------------
 
 * Incorporated by reference to the Company's Annual Report on Form 10-K for the
   year ended December 31, 1996.
 
** Incorporated by reference to the Company's Registration Statement on Form 10,
   File No. 1-12387, originally filed with the Commission on October 30, 1996,
   as amended.
 
    The Company will submit or has submitted the Plan, and hereby undertakes to
submit any amendments thereto, to the Internal Revenue Service in a timely
manner and has made or will make all changes required by the Internal Revenue
Service in order to qualify said Plan.
 
ITEM 9.  UNDERTAKINGS.
 
A.  SUBSEQUENT DISCLOSURE.
 
    The Company hereby undertakes:
 
    (1) To file, during any period in which offers or sales are being made of
       the securities registered hereby, a post-effective amendment to this
       Registration Statement:
 
            (i) To include any prospectus required by section 10(a)(3) of the
       Securities Act;
 
            (ii) To reflect in the prospectus any facts or events arising after
       the effective date of this Registration Statement (or the most recent
       post-effective amendment thereof) which, individually or in the
       aggregate, represent a fundamental change in the information set forth in
       this Registration Statement;
 
           (iii) To include any material information with respect to the plan of
       distribution not previously disclosed in this Registration Statement or
       any material change to such information in this Registration Statement;
 
Provided, however, that the undertakings set forth in paragraphs (i) and (ii)
above do not apply if the information required to be included in a
post-effective amendment by those paragraphs is contained in
 
                                       4
periodic reports filed with or furnished to the Commission by the Company,
pursuant to Section 13 or Section 15(d) of the Exchange Act that are
incorporated by reference in this Registration Statement.
 
    (2) That, for the purpose of determining any liability under the Securities
       Act, each such post-effective amendment shall be deemed to be a new
       registration statement relating to the securities offered therein, and
       the offering of such securities at that time shall be deemed to be the
       initial bona fide offering thereof.
 
    (3) To remove from registration by means of a post-effective amendment any
       of the securities being registered which remain unsold at the termination
       of the offering.
 
B.  INCORPORATION BY REFERENCE.
 
    The Company hereby undertakes that, for purposes of determining any
liability under the Securities Act, each filing of the Company's annual report
pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where
applicable, each filing of an employee benefit plan's annual report pursuant to
Section 15(d) of the Exchange Act) that is incorporated by reference in this
Registration Statement shall be deemed to be a new registration statement
relating to the securities offered therein, and the offering of such securities
at that time shall be deemed to be the initial bona fide offering thereof.
 
C.  COMMISSION POSITION ON INDEMNIFICATION.
 
    The Company hereby undertakes that, insofar as indemnification for
liabilities arising under the Securities Act may be permitted to directors,
officers and controlling persons of the Company pursuant to the foregoing
provisions, or otherwise, the Company has been advised that in the opinion of
the Commission such indemnification is against public policy as expressed in the
Securities Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the Company
of expenses incurred or paid by a director, officer or controlling person of the
Company in the successful defense of any action, suit or proceeding) is asserted
by such director, officer or controlling person in connection with the
securities being registered, the Company will, unless in the opinion of its
counsel the matter has been settled by controlling precedent, submit to a court
of appropriate jurisdiction the question whether such indemnification by it is
against public policy as expressed in the Securities Act and will be governed by
the final adjudication of such issue.
 
                                       5
SIGNATURES
 
    THE REGISTRANT.  Pursuant to the requirements of the Securities Act of 1933,
the Registrant certifies that it has reasonable grounds to believe that it meets
all of the requirements for filing on Form S-8 and has duly caused this
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Greenwich, State of Connecticut, on this 16th
day of May, 1997.
 
                                          TENNECO INC.
 
                                          By          /s/ DANA G. MEAD
 
                                          --------------------------------------
 
                                                       Dana G. Mead
                                           CHAIRMAN AND CHIEF EXECUTIVE OFFICER
 
    Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the date indicated.
 
            SIGNATURE                           TITLE                  DATE
----------------------------------  ------------------------------  -----------
 
         /s/ DANA G. MEAD
----------------------------------  Principal Executive Officer       May 16,
           Dana G. Mead               and Director                     1997
 
      /s/ ROBERT T. BLAKELY
----------------------------------  Principal Financial and           May 16,
        Robert T. Blakely             Accounting Officer               1997
 
Mark Andrews, W. Michael            Directors
Blumenthal, M. Kathryn Eickhoff,
Peter T. Flawn, Henry U. Harris,
Jr., Belton K. Johnson, John B.
McCoy, Sir David Plastow, William
L. Weiss, Clifton R. Wharton, Jr.
 
By      /s/ THEODORE R.
TETZLAFF
----------------------------------                                    May 16,
            Theodore R.                                                1997
Tetzlaff
               ATTORNEY-IN-FACT
SIGNATURES
 
    THE PLAN.  Pursuant to the requirements of the Securities Act of 1933, the
Committee appointed under the Tenneco Thrift Plan for Hourly Employees has duly
caused this Registration Statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of Greenwich, State of
Connecticut, on this 16th day of May, 1997.
 
                                          TENNECO THRIFT PLAN FOR HOURLY
                                          EMPLOYEES
 
                                          By          /s/ DANA G. MEAD
 
                                            ------------------------------------
 
                                                        Dana G. Mead
                                                  CHAIRMAN OF TENNECO INC.
                                                     BENEFITS COMMITTEE
EXHIBIT INDEX
EXHIBIT
  NUMBER                                                       DESCRIPTION
---------             ----------------------------------------------------------------------------------------------
*4.1  --         Restated Certificate of Incorporation of the Company.
 
     *4.2  --         Amended and Restated By-laws of the Company.
 
     *4.3  --         Rights Agreement, dated as of December 11, 1996, by and between Tenneco Inc. (formerly New
                      Tenneco Inc.) and First Chicago Trust Company of New York, as Rights Agent.
 
    **4.4  --         Form of Specimen Stock Certificate of Tenneco Inc. Common Stock.
 
      5.1  --         Opinion of Theodore R. Tetzlaff, Esq. as to the legality of the Common Stock being registered.
 
      15   --         None.
 
     23.1  --         Consent of Theodore R. Tetzlaff, Esq. (included in Exhibit 5).
 
     23.2  --         Consent of Arthur Andersen LLP.
 
     24.1  --         Powers of Attorney of the following Directors of the Company: Mark Andrews, W. Michael
                      Blumenthal, M. Kathryn Eickhoff, Peter T. Flawn, Henry U. Harris, Jr., Belton K. Johnson, John
                      B. McCoy, Sir David Plastow, William L. Weiss and Clifton R. Wharton, Jr.
 
      99   --         None.
------------------------
 
 * Incorporated by reference to the Company's Annual Report on Form 10-K for the
   year ended December 31, 1996.
 
** Incorporated by reference to the Company's Registration Statement on Form 10,
   File No. 1-12387, originally filed with the Commission on October 30, 1996,
   as amended.