<PAGE>
                                          
                                   UNITED STATES
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
                                          
                                    FORM 10-K/A
                                  Amendment No. 1

/ x /    Annual Report Pursuant to Section 13 or 15(d) of the Securities
Exchange Act of 1934

For the fiscal year ended April 30, 1998, or

/   /    Transition report pursuant to Section 13 or 15(d) of the
         Securities Exchange Act of 1934

         For the transition period from             to

         Commission File No. 0-16115
                                          
                          IMPCO Technologies, Inc.           
           ------------------------------------------------------
           (Exact name of registrant as specified in its charter)

               Delaware                             91-1039211
        ------------------------              -----------------------
        (State of Incorporation)              (IRS Employer ID. No.)

          16804 Gridley Place, Cerritos, California    90703    
         -----------------------------------------------------------
          (Address of Principal Executive Offices)  (Zip Code)

     Registrant's telephone number, including area code: (562) 860-6666

         Securities registered pursuant to Section 12(b) of the Act:
                                    None
        Securities registered pursuant to Section 12(g) of the Act:
                               Common Stock
     
     Indicate by check mark whether the registrant: (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months, and (2) has been subject to such filing
requirements for the past 90 days. 
          Yes   x                 No         
              -----                  -----

     Indicate by check mark if disclosure of delinquent filers pursuant to Item
405 of Regulation S-K is not contained herein, and will not be contained, to the
best of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K. /    /
     
     Approximate aggregate market value of the voting stock held by 
non-affiliates of the registrant as of June 30, 1998 was $115,238,516
     
     Number of shares outstanding of each of the registrant's classes of common
stock, as of June 30, 1998:
     
                      7,091,601 shares of Common Stock
     
                    Documents incorporated by reference:
     
                                See Item 14
     
     Part III (Items 10, 11, 12 and 13) is hereby added to registrant's Form 
10-K filed on July 29, 1998

<PAGE>
                                                                             2

                                  PART III
                                               
     
ITEM 10  -  DIRECTORS AND EXECUTIVE OFFICERS OF THE REGISTRANT
     
     The following table sets forth information concerning the executive
officers and directors of the Company as of April 30, 1998:
     
<TABLE>
<CAPTION>

Name                               Age       Position With Company
----                               ---       ---------------------
<S>                               <C>       <C>
Robert M. Stemmler (1). . . . . .  62        President, Chief Executive    
                                              Officer and Director    

Thomas M. Costales. . . . . . . .  51        Treasurer and Chief Financial
                                              Officer
     
Dale L. Rasmussen . . . . . . . .  48        Senior Vice President and 
                                              Secretary
     
Syed Hussain. . . . . . . . . . .  45        Vice President of Technology 
                                              and Automotive OEM Operations
     
Hans J. Roehricht . . . . . . . .  57        Vice President of Gaseous Fuel
                                              Products until July 16, 1997
     
Norman L. Bryan (2) . . . . . . .  57        Director
     
V. Robert Colton (1). . . . . . .  68        Director
     
Paul Mlotok (1) . . . . . . . . .  53        Director
     
Christopher G. Mumford (2). . . .  52        Director
     
Edward L. Scarff (3). . . . . . .  67        Director
     
Don J. Simplot (2). . . . . . . .  63        Director
     
Rawland F. Taplett (3). . . . . .  77        Director
     
Douglas W. Toms (3) . . . . . . .  68        Director

</TABLE>
-------------------
(1)  Term as Board of Director member expires 1998.
(2)  Term as Board of Director member expires 1999.
(3)  Term as Board of Director member expires 2000.
     
     The Board of Directors is divided into three classes, each consisting of
three Directors, with the three classes serving staggered three-year terms. The
executive officers are elected annually by the Board of Directors and serve at
the pleasure of the Board of Directors.
     
     ROBERT M. STEMMLER has been a Director since May 1993, and became the 
President and Chief Executive Officer of the Company on July 1, 1993 and has 
acted as interim Chair of the Board of Directors since June 1998. He was a 
full-time consultant to the Company from December 1992 until becoming 
President and CEO. From 1988 until December 1992, Mr. Stemmler was the Chief 
Operating Officer of Sargent Fletcher Company, a manufacturer of fuel tanks, 
aerial refueling systems and specialty mission equipment for military 
aircraft. He was the General Manager of IMPCO Technologies, Inc. from 1982 to 
1985.
     
     THOMAS M. COSTALES has been the Treasurer and Chief Financial Officer of
the Company since March 1995. From September 1993 until joining the Company, he
was Vice President and Controller of the Omnifax division of Danka Industries,
Inc. He held a similar position with


<PAGE>
                                                                             3

Omnifax's predecessor, Telautograph Corporation, from 1987 until it was 
acquired by Danka Industries.
     
     DALE L. RASMUSSEN has been Senior Vice President and Secretary since June
1989. He jointed the Company in 1984 as Vice President of Finance and
Administration.
     
     SYED HUSSAIN has been Vice President of Technology and Automotive OEM
Operations since 1996. Mr. Hussain joined the Company in 1993 and held various
positions with the Company before becoming a Vice President.
     
     HANS J. ROEHRICHT was Vice President of Gaseous Fuel Products from November
1996 until July 16, 1997, and is now Director of Strategic Planning. He jointed
the Company in 1990 and held various positions with the Company prior to
November 1996.
     
     NORMAN L. BRYAN has been a Director since November 1993 and is Chair of the
Audit Committee. He has been a consultant since 1995. Prior to retiring in 1994
from Pacific Gas and Electric Company, he was Vice President, Marketing from
February 1993 until December 1994, and was Vice President, Clean Air Vehicles
from February 1991 to February 1993.
     
     V. ROBERT COLTON has been a Director of the company since March 1989. Mr.
Colton is a retired dentist and has engaged in real estate investments and
development activities for a number of years.
     
     PAUL MLOTOK has been a Director of the Company since April 1997 and is
Chair of the Strategic Planning Committee. He has been a Principal of Global
Business Network, a consulting firm specializing in strategy development
particularly in the energy and natural resources industries, since June 1995.
From 1989 to 1995, he was a Principal and analyst at Morgan Stanley & Co.
     
     CHRISTOPHER G. MUMFORD has been a Director since June 1998. He is a private
investor and was a Managing Director of Questor Partners Fund, L.P., a private
investment partnership, from 1995 through 1997. He has served as a Director of
Crown Pacific Partners, L.P. and predecessor entities since 1992, and has served
as an officer or director of other private companies, including Executive Vice
President, Treasurer, Chief Financial Officer and Director of Arcata Corporation
1982-1994, Director of Ryder TRS, Inc. 1996-1997 and Director of Ockham Personal
Insurance Holdings PLC (London, England) 1996-1997.
     
     EDWARD L. SCARFF has been a Director since June 1998. He is a private
investor and has been a Principal of the General Partner of Questor Partners
Fund, L.P., a private investment partnership, since 1995. He has been a director
of The Clorox Company since 1986. He has also been an officer or director of
numerous private companies, including Director of Channel Master Holdings since
1997, Director of Ryder TRS, Inc. 1996-1998, Director of Ockham Personal
Insurance Holdings PLC (London, England) 1996-1997 and Chairman of Arcata
Corporation 1982-1994.
     
     DON J. SIMPLOT has been a Director since May 1978 and is Chair of the
Compensation Committee. He is the President of Simplot Industries, Inc., which
is engaged in agricultural enterprises, and a Vice President of J.R. Simplot
Company, which is also engaged in agricultural enterprises. Mr. Simplot is a
Director of Micron Technology, Inc., a designer and manufacturer of
semiconductor memory components primarily used in various computer applications.


<PAGE>
                                                                             4

     RAWLAND F. TAPLETT has been a Director of the Company since May 1978 and is
Chair of the Executive Committee. He served as Chair of the Board of Directors
from 1979 to 1992. He is the founder and owner of R.F. Taplett Fruit and Storage
Company, a grower, packer and marketer of fruit, primarily apples.
     
     DOUGLAS W. TOMS has been a Director of the Company since October 1980. He
served as President and Chief Executive Officer of the Company from October 1980
to April 1989. Since April 1989, Mr. Toms has been a consultant to American
Honda Motor Company, Inc.
     
              SECTION 16(a) BENEFICIAL OWNERSHIP REPORTING COMPLIANCE
     
     Section 16(a) of the Securities Exchange Act of 1934 requires the 
Company's directors and executive officers, and persons who own more than 10% 
of the Company's Common Stock to file with the Securities and Exchange 
Commission ("SEC") initial reports of ownership and reports of changes in 
ownership of Common Stock and other equity securities of the Company. 
Officers, directors and greater than 10% stockholders are required by SEC 
regulation to furnish the Company with copies of all Section 16(a) reports 
they file. To the Company's knowledge, based solely on review of the copies 
of such reports furnished to the Company or advice that no filings were 
required, during fiscal year 1998 all officers, directors and greater than 
10% beneficial owners complied with the Section 16(a) filing requirements, 
except one Form 4 was filed late by each of Peter B. Bensinger (one 
transaction), Thomas M. Costales (two transactions), Syed Hussain (two 
transactions), Robert M. Stemmler (two transactions), and Edwin J. Schneebeck 
(seven transactions), and two Form 4's were filed late by Dale L. Rasmussen 
(one transaction and two transactions).
     
ITEM 11  -  EXECUTIVE COMPENSATION
     
     The following table sets forth certain information regarding compensation
paid during each of the Company's last three fiscal years to the Company's chief
executive officer and the Company's four other most highly compensated executive
officers.

                           SUMMARY COMPENSATION TABLE

<TABLE>
<CAPTION>
                                                                    
                                                                     Long Term  
                                                                    Compensation 
                                          Annual Compensation          Awards   
                                       -------------------------    -------------
                                                                     Securities  
                                                                     Underlying  
     Name and                 Fiscal     Salary         Bonus          Options           All Other
Principal Position             Year      ($) (1)         ($)         (in shares)        Compensation
--------------------------    ------    --------      ---------     -------------       --------------
<S>                           <C>       <C>           <C>           <C>                 <C>
Robert M. Stemmler             1998     $229,673      $  96,000       200,139 (2)        $ 25,631 (3)
  President and Chief          1997      197,917         62,600        58,535 (2)          31,181
  Executive Officer            1996      198,000         61,500        20,000 (2)          25,878

Dale L. Rasmussen              1998     $ 92,633      $  26,000        60,000 (2)        $ 15,869 (4)
  Senior Vice President        1997       92,000         12,000        12,000 (2)          16,170
  and Secretary                1996       93,416         13,000          -0-               14,865
                                                                     
Syed Hussain                   1998     $134,321      $  30,500       100,000 (2)        $ 13,052 (5)
  Vice President of            1997      108,333         27,900        17,000 (2)          10,900
  Technology and               1996       94,385         23,000         3,000 (2)           9,400
  Automotive OEM


<PAGE>
                                                                             5
  Operations

Thomas M. Costales             1998     $118,458      $  36,000        40,237 (2)        $ 19,238 (6)
  Treasurer and Chief          1997      104,188         30,600         7,048 (2)          17,355
  Financial Officer            1996      101,755         17,300          -0-               15,249

Hans Roehricht                 1998     $128,167 (7)  $  30,500       100,276 (2)        $ 19,812 (8)
  Vice President of            1997      109,167         24,300        11,035 (2)          15,793
  Gaseous Fuel Products        1996      101,538         17,000         2,500 (2)          13,990

</TABLE>
----------------------
(1)  Includes amounts deferred by executive officers pursuant to the IMPCO
     Employee Savings Plan and Deferred Compensation Plan.

(2)  Options under Incentive Stock Option Plans.

(3)  Group term life insurance premium of $9,828, Christmas bonus of $1,000,
     automobile allowance of $11,791 and Company's contribution of $3,012
     pursuant to the IMPCO Employee Savings Plan.

(4)  Group term life insurance premium of $1,414, Company's contribution of
     $2,126 pursuant to the IMPCO Employee Savings Plan, Christmas bonus of
     $1,000 and automobile allowance of $11,329.

(5)  Group term life insurance premium of $261, Christmas bonus of $1,000 and
     automobile allowance of $11,791.

(6)  Group term life insurance premium of $4,032, Company's contribution of
     $2,415 pursuant to the IMPCO Employee Savings Plan, Christmas bonus of
     $1,000 and automobile allowance of $11,791.

(7)  Mr. Roehricht was an executive officer of the Company until July 16, 1997.

(8)  Group life insurance premium of $4,050, Company's contribution of $2,971 to
     the IMPCO Employee Savings Plan, Christmas bonus of $1,000 and automobile
     allowance of $11,791.
     
                                          
                        OPTIONS GRANTED IN FISCAL YEAR 1998
               
     The following table provides information with respect to options granted 
during the last fiscal year.

<TABLE>
<CAPTION>
                                        Individual Grants 
                        -----------------------------------------------------
                        Number of      % of Total
                        Shares         Options
                        Underlying     Granted to     Exercise
                        Options        Employees in   Price Per   Expiration
Name                    Granted (1)    Fiscal Year    Share       Date      
----                    -----------    ------------   ---------   -----------
<S>                     <C>            <C>            <C>         <C>
Robert M. Stemmler      200,000            25%         $ 7.63     05/22/07
                                                                         
Robert M. Stemmler          139             0%          11.00     01/02/08
                                                                         
Dale L. Rasmussen        40,000             5%           7.63     05/22/07


<PAGE>
                                                                             6
                                                    
Dale L. Rasmussen        20,000             3%           8.00     06/30/07
                                                    
Syed Hussain            100,000            13%           7.63     05/22/07
                                                                         
Thomas M. Costales       40,000             5%           7.63     05/22/07
                                                    
Thomas M. Costales          237             0%          11.00     01/02/08
                                                    
Hans J. Roehricht       100,000            13%           7.63     05/22/07
                                                    
Hans J. Roehricht           276             0%          11.00     01/02/08

</TABLE>
                                                  
                                POTENTIAL REALIZABLE
                              VALUE AT ASSUMED ANNUAL
                                RATES OF STOCK PRICE
                          APPRECIATION FOR OPTION TERM (2)
                                          
<TABLE>
<CAPTION>


Name                                  5%                  10%
----                               --------            ----------
<S>                                <C>                 <C>
Robert M. Stemmler                 $960,655            $2,434,488

Dale L. Rasmussen                   292,562               741,409

Syed Hussain                        479,847             1,216,025

Thomas M. Costales                  193,578               490,565

Hans J. Roehricht                   481,756             1,220,864

</TABLE>
--------------------------
(1)  Material terms of options granted under the Incentive Stock Option Plans
     are as follows:  Options are granted at the fair market value of the Common
     Stock on the date of grant and vest cumulatively at the rate of 40% after
     the first two years following the date of the grant and 20% each year
     thereafter so that the employee is 100% vested after five years. However,
     if employment terminates due to death or disability, retirement at or after
     age 62, or termination without cause, then options vest at the rate of 25%
     for each full calendar year of employment. Options may be exercised only
     while an optionee is employed by the Company, or within three months
     following termination of employment. However, if termination results from
     death or disability, options may be exercised within one year of the
     termination date. In no event may options be exercised more than ten years
     after date of grant.

(2)  Based on ten-year option term and annual compounding at rates shown.
     The dollar amounts under these columns are the results of calculations
     at the 5% and 10% rates set by the Securities and Exchange Commission
     and, therefore, are not intended to forecast possible future
     appreciation, if any, of the Common Stock. No gain to optionees is
     possible without stock price appreciation, which will benefit all
     stockholders on a commensurate basis.
     

<PAGE>
                                                                             7

                  AGGREGATED OPTION EXERCISES IN FISCAL YEAR 1998
                                        AND
                           FISCAL YEAR-END OPTION VALUES
     
     The following table provides information with respect to exercise of 
options during fiscal year 1998 and the value of unexercised options at the 
end of fiscal year 1998.

<TABLE>
<CAPTION>

                 Shares                            Number of
                Acquired                          Unexercised                Value of Unexercised
                   On          Value          Options (in shares)            In-The-Money Options
                Exercise      Realized         at Fiscal Year-End           At Fiscal Year-End(2)
   Name           (#)         ($) (1)      Exercisable/Unexercisable      Exercisable/Unexercisable
----------      --------      --------     -------------------------      -------------------------
<S>             <C>           <C>          <C>                            <C>                   
Robert M.         -0-           -0-            117,500 / 281,174             $426,675 /$1,348,490
Stemmler

Dale L.          19,380       $226,552          58,334 /  72,000              449,506 /   359,800
Rasmussen

Syed             13,200       $ 62,280           -0-   / 118,800                  -0- /   593,766
Hussain

Thomas M.         -0-           -0-             9,000  /  50,285               31,500 /   242,686
Costales

Hans J.           -0-           -0-             6,833  / 112,811               42,035 /   555,575
Roehricht

</TABLE>
-------------------------
(1)  Calculated by determining the difference between the fair market value of
     the Common Stock underlying the options on the date each option was
     exercised and the exercise price of the options.

(2)  Calculated by determining the difference between the fair market value
     of the Common Stock underlying the options on April 30, 1998 ($12.50)
     and the exercise price of the options.
     
                                          
                               EMPLOYMENT AGREEMENTS
     
     An Employment Agreement between the Company and Robert M. Stemmler provides
for two consecutive twelve month periods of employment of Mr. Stemmler as the
President and Chief Executive Officer, commencing April 1, 1997. It is subject
to certain termination events, which include Mr. Stemmler's resignation and the
Company's right to terminate him with or without cause upon payment of lump sum
equal to 100% in the first term and 75% in the second term, respectively, of
base salary, plus certain incentive compensation and payment of benefits for a
period following termination. The Employment Agreement requires payment of an
annual base salary of $230,000, and payment of incentive compensation under the
Company's Bonus Incentive Plan.
                                          
                             COMPENSATION OF DIRECTORS
     
     Each Director who is not an employee of the Company is paid an attendance
fee of $1,000, plus out-of-pocket expenses, for each Board or committee meeting
attended. In addition, annual remuneration is paid to the following: Chair of
the Board of Directors - $25,000; Chair of the Executive Committee - $15,000;
Chair of Strategic Planning Committee - $5,000; Chairs of Audit and Compensation
Committees - $3,000.
     
     A total of 290,000 options have been granted to Directors under the 1993
Stock Option Plan for Nonemployee Directors, of which 210,000 remain


<PAGE>
                                                                             8

unexercised and are held by Messrs. Bryan, Colton, Mlotok, Simplot, Taplett 
and Toms. 60,000 options were available for future grants as of April 30, 
1998. Option exercise prices are the higher of (i) the average market value 
of the stock for the 15 trading days following the date of grant and (ii) the 
market value on the fifteenth trading day following the date of grant. 
Options are not assignable and vest cumulatively at the rate of 25% annually, 
beginning on the first anniversary date of grant. However, if a Director 
dies, becomes disabled or retires at age 62 or later, then options vest at 
the rate of 25% for each full calendar year in which optionee served as a 
Director of the Company. Options must be exercised while a Director or within 
three months following termination as Director, unless termination results 
from death or disability, in which case options may be exercised during the 
one-year period following termination. In no event may options be exercised 
more than ten years after date of grant.
                                           

                           COMPENSATION COMMITTEE REPORT
                             ON EXECUTIVE COMPENSATION
     
     The following report on executive compensation is furnished by the Board of
Directors. In fiscal year 1998, as in prior years, the nonmanagement members of
the Board of Directors determined the compensation to be paid to the executive
officers. An Employment Agreement with Robert M. Stemmler was in effect during
the fiscal year. See "Employment Agreement."
                                          

                           FISCAL YEAR 1998 COMPENSATION
     
                              COMPENSATION PHILOSOPHY

     Compensation of the  executive officers is designed to link compensation
directly to the Company's growth and financial performance. Compensation
consists of base compensation, a Bonus Incentive Plan and options under
Incentive Stock Option Plans. The objective of these three elements, taken
together, is to provide reasonable base compensation and to retain, recognize
and reward superior performance. The compensation philosophy also ensures that
the Company provides a comprehensive compensation package that is competitive in
the marketplace.
     
                                BONUS INCENTIVE PLAN
     
     The Company has a Bonus Incentive Plan which includes a bonus incentive
plan for the chief executive officer and a bonus incentive pool for the
executive officers and staff. These bonus plans have two components:  A "revenue
portion" which is based upon the percentage increase of the Company's gross
revenues to the extent gross revenues exceed 110% of the prior fiscal year gross
revenues, and an "earnings before interest and taxes (EBIT) portion" which is
based upon the incremental growth in EBIT over the prior fiscal year. The
minimum bonus payable to the chief executive officer is 1.5% of the current
fiscal year's EBIT and the maximum bonus is 75% of current salary. The minimum
bonus pool for the other executive officers and staff is 4% of the current
fiscal year's EBIT and the maximum bonus pool is 50% of their current aggregate
salaries.

<PAGE>
                                                                             9

                              DEFERRED COMPENSATION PLAN
     
     The Board of Directors has adopted a Deferred Compensation Plan to provide
a select group of management and highly compensated employees and Directors with
the opportunity to participate in a deferred compensation program. Under the
program, participants may defer up to 100% of their base compensation and
bonuses. The Company is required to make certain matching contributions, a
portion of which is options to purchase the Company's Common Stock granted under
the Incentive Stock Option Plan and another portion is shares of the Company's
Common Stock, subject to vesting provisions. The options are to be granted on
the first day of each calendar year during which the Company's Common Stock is
traded and the exercise price is the closing price on the Nasdaq National Market
or such stock exchange on such first trading day. The plan is not qualified
under Section 401 of the Internal Revenue Code. The Company will pay
participants upon retirement or termination of employment an amount equal to the
amount of deferred compensation plus investment returns and vested shares of the
Company's Common Stock.
     
                                  CEO COMPENSATION
     
     Robert M. Stemmler served as chief executive officer pursuant to an
Employment Agreement pursuant to which he was paid a base salary at an annual
rate of $230,000. In addition to the base salary, Mr. Stemmler is eligible for
an annual cash bonus under the Bonus Incentive Plan during each fiscal year. Mr.
Stemmler's bonus for fiscal year 1998 was $96,000.
     
     As longer term compensation, options were granted to purchase 150,000
shares of Common Stock under the Company's Incentive Stock Option Plan. In
addition, Mr. Stemmler was granted options to purchase an additional 50,000
shares of Common Stock which vest only if on or prior to April 30, 1999 the
trading price of the Common Stock equals or exceeds (a) $17.00 per share on any
trading day or (b) $15.30 during 20 of 30 consecutive trading days. The 
trading price requirement was satisfied on June 26, 1998.  The options
are intended to induce Mr. Stemmler's continued employment, allow him to
participate in the ownership of the Company, and provide further long-term
incentive to advance the interest of the Company and increase the value of the
Company's Common Stock.
     
                              OTHER EXECUTIVE OFFICERS
     
     In reviewing and approving base salaries for the executive officers, the
Compensation Committee relies on independent industry surveys to assess the
Company's salary competitiveness and salary range for each position. Base salary
is based upon individual performance, experience, competitive pay practices and
level of responsibilities. Base salaries in fiscal year 1998 reflected the
Committee's determination of compensation levels required to remain competitive,
given each executive officer's performance, the Company's performance and the
competitive environment for executive talent. The purpose of stock options is to
induce selected, key employees of the Company to remain employed with the
Company, to participate in the ownership of the Company, to advance the
interests of the Company and to increase the value of the Company's Common
Stock.


<PAGE>
                                                                            10
     
     The foregoing report was made by the members of the Compensation Committee.
     
     
                                        Don J. Simplot, Chair    
                                        Norman L. Bryan
                                        Rawland F. Taplett       
     
                      OPTIONS GRANTED BY CERTAIN STOCKHOLDERS
     
     On June 5, 1998, Questor Partners Fund, L.P. and its affiliate, Questor
Side-by-Side Partners, L.P. (together, "Questor"), purchased shares of the
Company's Common Stock and 1993 Series 1 Preferred Stock from the estate and
family of a deceased stockholder and on the same day granted options to certain
officers of the Company to purchase of shares of Common Stock as follows:

<TABLE>
<CAPTION>
              <S>                                <C>     
               Robert M. Stemmler                 113,858
               Syed Hussain                       113,858
               Dale L. Rasmussen                   56,928
</TABLE>
     
     The option exercise price is $13.75 per share. The options vest at the rate
of 25% annually commencing June 30, 1999. The options become exercisable only
after Questor's 1993 Series 1 Preferred Stock is converted (or is convertible at
the option of Questor) into Common Stock and then upon the earlier of (i)
June 5, 2003 and (ii) the sale by Questor of 50% or more of the Common Shares
owned by it as of June 5, 1998 (including 614,250 shares of Common Stock into
which the 1993 Series 1 Preferred Stock owned by Questor is convertible). The
options will not be exercisable after December 31, 2003, and any option that is
not vested upon termination of the full-time employment of the option holder
with IMPCO (other than because of death or disability) will terminate.
     
                           COMPARATIVE STOCK PERFORMANCE
     
     The graph below compares the cumulative total stockholder return on the
Company's Common Stock for the last five fiscal years with the cumulative total
return of the CRSP Total Return Index for The Nasdaq Stock Market Index and the
Nasdaq Trucking and Transportation Stock Index over the same period (assuming
the investment of $100 and reinvestment of all dividends).
     
     
     
     
             EDGAR REPRESENTATION OF DATA POINTS USED IN PRINTED GRAPH
     
<PAGE>
                                                                            11
<TABLE>
<CAPTION>
                                        Nasdaq
          Value at                      Trucking
          April 30  IMPCO     Nasdaq    Transportation
          --------  -----     ------    --------------
          <S>       <C>       <C>       <C>
          1993      100.0     100.0     100.0
          1994      207.3     111.3     113.3
          1995      165.9     129.4     113.3
          1996      163.4     184.4     134.3
          1997      151.2     195.2     131.6
          1998      243.9     292.1     192.9
</TABLE>
     
ITEM 12  -  SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND 
             MANAGEMENT
     
                            VOTING SECURITIES
     
     The voting securities of the Company consist of Common Stock and 1993
Series 1 Preferred Stock. At August 1, 1998, 7,187,436 shares of Common Stock
and 5,950 shares of 1993 Series 1 Preferred Stock were outstanding.
     
     Each outstanding share of Common Stock is entitled to one vote on all
matters to be presented to stockholders for a vote. Each share of 1993 Series 1
Preferred Stock is also entitled to vote on all such matters and is entitled to
the number of votes equal to the number of full shares of Common Stock into
which it is convertible. On August 1, 1998, each share of 1993 Series 1
Preferred Stock was convertible into the number of shares of Common Stock that
results from dividing $1,000 by a conversion price of $5.29 per share, or 189
votes per share.
                                               
                               COMMON STOCK
     
     The following table sets forth information as of August 1 1998, with
respect to all stockholders known by the Company to be the beneficial owners of
more than 5% of the outstanding Common Stock. Except as otherwise specified,
each named beneficial owner has sole voting and investment power with respect to
the shares set forth opposite its name.

<TABLE>
<CAPTION>
     
Name and Address                   Amount and Nature of    Percent
of Beneficial Owner                Beneficial Ownership    of Class
---------------------------        --------------------    --------
<S>                                <C>                     <C>
Questor Partners Fund, L.P.             2,034,211 (1)       26.07%
  103 Springer Building
  3411 Silverside Road
  Wilmington, DE  19810
     
Rawland F. Taplett                        586,892 (2)        7.92%
  P.O. Box 2188
  Wenatchee, WA  98801
     
BERU Aktiengesellschaft                   558,478            7.77%
  Moerikestrasse 155
  Ludwigsburg, Germany

</TABLE>
------------------------
(1)  Includes 95,095 shares of common stock owned by Questor Side-by-Side
     Partners, L.P. ("Questor SBS"), 573,048 shares subject to conversion rights
     under 3,032 shares of 1993 Series 1 Preferred Stock and


<PAGE>
                                                                            12

     41,202 shares subject to conversion rights under 218 shares of 1993
     Series 1 Preferred Stock owned by Questor SBS.

(2)  Includes 50,000 shares subject to options under the Directors Stock Option
     Plan and 170,100 shares subject to conversion rights under 900 shares of
     1993 Series 1 Preferred Stock.
     
                                          
                                PREFERRED STOCK
     
     The following table sets forth information as of August 1, 1998, with
respect to all stockholders known by the Company to be the beneficial owners of
more than 5% of the outstanding 1993 Series 1 Preferred Stock. Except as
otherwise specified, each named beneficial owner has sole voting and investment
power with respect to the shares set forth opposite his name.

<TABLE>
<CAPTION>
     
    Name of                       Amount and Nature of     Percent
Beneficial Owner                  Beneficial Ownership     of Class
----------------                  --------------------     --------
<S>                               <C>                      <C>
Questor Partners Fund, L.P.             3,250 (1)           54.62%
  103 Springer Building
  3411 Silverside Road
  Wilmington, DE  19810

Don J. Simplot                            900               15.13%
  P.O. Box 27
  Boise, ID  83707

Rawland F. Taplett                        900               15.13%
  P.O. Box 2188
  Wenatchee, WA  98801

Douglas W. Toms                           450                7.56%
  2001 Lakewood
  Olympia, WA  98501
     
Dale L. Rasmussen                         450                7.56%
  29409 - 232nd Avenue S.E.
  Black Diamond, WA  98010              -----              -------
                                        5,950              100.00%
</TABLE>
--------------------
(1) Includes 218 shares owned by Questor Side-by-Side Partners, L.P.

<PAGE>
                                                                            13
                                          
                            OWNERSHIP OF MANAGEMENT
     
     The following table sets forth information as of August 1, 1998, as to the
number of shares of Common Stock and 1993 Series 1 Preferred Stock beneficially
owned by (i) each Director, (ii) the executive officers named in the Summary
Compensation Table and (iii) all Directors and executive officers as a group.
Except as otherwise specified, each named beneficial owner has sole voting and
investment power with respect to the shares set forth opposite his name.

<TABLE>
<CAPTION>

Title of         Name of Beneficial      Amount and Nature of       Percent of
Class            Owner                   Beneficial Ownership         Class
--------         ------------------      --------------------       ----------
<S>              <C>                     <C>                        <C>
Common           Norman L. Bryan                21,000 (1)                *
                                                                    
Common           V. Robert Colton              146,666 (2)              2.03%
                                                                    
Common           Thomas M. Costales             10,000 (3)                *
                                                                    
Common           Syed Hussain                     -0-                     *
                                                                    
Common           Paul Mlotok                     5,000 (4)                *
                                                                    
Common           Christopher G.              2,034,211 (5)              26.07%
                 Mumford                                            
                                                                    
Common           Dale L. Rasmussen             144,981 (6)               1.98%
                                                                    
Common           Hans Roehricht                  6,833 (7)                *
                                                                    
Common           Edward L. Scarff            2,034,211 (8)              26.07%
                                                                    
Common           Don J. Simplot                295,901 (9)               4.01%
                                                                    
Common           Robert M. Stemmler            131,241 (10)              1.79%
                                                                    
Common           Rawland F. Taplett            586,892 (11)              7.92%
                                                                    
Common           Douglas W. Toms               240,715 (12)              3.29%
                                                                    
Common           All executive               3,623,440                  41.64%
                 officers and
                 directors as a group
                 (13 persons)

Preferred        See "Ownership of
                 Certain Beneficial
                 Owners - Preferred
                 Stock" for ownership
                 of 1993 Preferred
                 Stock


                 All executive
                 officers and                         
                 directors as a group            5,950 (13)            100.00%
                 (13 persons)
</TABLE>

<PAGE>
                                                                            14
------------------------
 *    Less than 1%

(1)  Includes 20,000 shares subject to options under Directors Stock Option
     Plan.

(2)  Includes 30,000 shares subject to options under Directors Stock Option
     Plan. Mr. Colton's term as a Director ends in 1998 and he had declined to
     be nominated for reelection to the Board of Directors.

(3)  Includes 9,000 shares subject to options under Incentive Stock Option Plan.

(4)  5,000 shares subject to options under Directors Stock Option Plan.

(5)  Shares voting and investment power with respect to shares beneficially
     owned by Questor Partners Fund, L.P. and Questor Side-by-Side Partners,
     L.P. See "Ownership of Certain Beneficial Owners."

(6)  Includes 25,000 shares subject to options under Incentive Stock Option
     Plan, 33,334 shares subject to options under the 1991 Executive Stock
     Option Plan and 85,050 shares subject to conversion rights under 450 shares
     of 1993 Series 1 Preferred Stock.

(7)  6,833 shares subject to options under Incentive Stock Option Plan. Mr.
     Roehricht was an officer of the Company until July 16, 1997.

(8)  Shares voting and investment power with respect to shares beneficially
     owned by Questor Partners Fund, L.P. and Questor Side-by-Side Partners,
     L.P. See "Ownership of Certain Beneficial Owners."

(9)  Includes 30,000 shares subject to options under Directors Stock Option Plan
     and 170,100 shares subject to conversion rights under 900 shares of 1993
     Series 1 Preferred Stock.

(10) Includes 130,000 shares subject to options under Incentive Stock Option
     Plan and 1,241 shares held in a self-directed 401(k) plan.

(11) Includes 50,000 shares subject to options under Directors Stock Option Plan
     and 170,100 shares subject to conversion rights under 900 shares of 1993
     Series 1 Preferred Stock.

(12) Includes 50,000 shares subject to options under Directors Stock Option Plan
     and 85,050 shares subject to conversion rights under 450 shares of 1993
     Series 1 Preferred Stock.

(13) Includes 3,250 shares owned by Questor Partners Fund, L.P. and Questor
     Side-by-Side Partners, L.P. See footnotes (5) and (8) above.
     

ITEM 13  -  CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS
     
     None.

<PAGE>
                                                                            15

SIGNATURES
----------
     
Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, the registrant has duly caused this report to be
signed on its behalf by the undersigned thereunto duly authorized.

Dated August 27, 1998.

                                   IMPCO TECHNOLOGIES, INC.


                                   By /s/Thomas M. Costales
                                      --------------------------
                                      Thomas M. Costales,
                                      Chief Financial Officer
                                      and Treasurer