Borgwarner Inc — Additional Proxy Materials (DEFA14A)

☑    Filed by the Registrant

☐   Filed by a party other than the Registrant

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☐    Preliminary Proxy Statement

☐    Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

☐    Definitive Proxy Statement

☑    Definitive Additional Materials

☐    Soliciting Material under §240.14a-12

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☑    No fee required

☐    Fee paid previously with preliminary materials

☐    Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11

Your Vote Counts! Smartphone users Point your camera here and vote without entering a control number For complete information and to vote, visit www.ProxyVote.com Control # QAARV1-P12345 Get informed before you vote Ricky Campana P.O. Box 123456 Suite 500 51 Mercedes Way Edgewood, NY 11717 148,294 322,224 1 OF 4 30# XXXX XXXX XXXX XXXX V2.1 BORGWARNER INC. 2026 Annual Meeting Vote by April 28, 2026 11:59 PM ET BORGWARNER INC. ATTN: FAVIOLA BOGEN 3850 HAMLIN RD. AUBURN HILLS, MI 48326 You invested in BORGWARNER INC. and it's time to vote! You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy material for the stockholder meeting to be held on April 29, 2026. View the Notice & Proxy Statement, Annual Report on Form 10-K online OR you can receive a free paper or email copy of the material(s) by requesting prior to April 15, 2026. If you would like to request a copy of the material(s) for this and/or future stockholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy. Vote in Person at the Meeting* April 29, 2026 9:00 AM EDT 3850 Hamlin Road Auburn Hills, Michigan, 48326 *Please check the meeting materials for any special requirements for meeting attendance. At the meeting, you will need to request a ballot to vote these shares.

THIS IS NOT A VOTABLE BALLOT Vote at www.ProxyVote.com Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click “Delivery Settings”. QAARV2-P12345 Voting Items Board Recommends Control # XXXX XXXX XXXX XXXX THE COMPANY NAME INC. - COMMON ASDFGHJKL 123456789.1234 THE COMPANY NAME INC. - CLASS A 123456789.1234 THE COMPANY NAME INC. - CLASS B 123456789.1234 THE COMPANY NAME INC. - CLASS C 123456789.1234 THE COMPANY NAME INC. - CLASS D 123456789.1234 THE COMPANY NAME INC. - CLASS E 123456789.1234 THE COMPANY NAME INC. - CLASS F 123456789.1234 THE COMPANY NAME INC. - 401 K 123456789.1234 SHARE CLASSES REPRESENTED FOR VOTING 1.00000 322,224 148,294 CLT ID This is an overview of the proposals being presented at the upcoming stockholder meeting. Please follow the instructions on the reverse side to vote these important matters. 1. Election of Directors Nominees: 1A Joseph F. Fadool For 1B Sara A. Greenstein For 1C Michael S. Hanley For 1D Shaun E. McAlmont For 1E Deborah D. McWhinney For 1F Alexis P. Michas For 1G Sailaja K. Shankar For 1H Hau N. Thai-Tang For 2. Approve, on an advisory basis, the compensation of our named executive officers. For 3. Ratify the selection of PricewaterhouseCoopers LLP as the independent registered public accounting firm for the Company for 2026. For 4 Approve the Amended and Restated BorgWarner Inc. 2023 Stock Incentive Plan. For 5 Vote on stockholder proposal regarding action by written consent. Against NOTE: Transact such other business as may properly come before the meeting or any adjournment or postponement thereof.

Get informed before you vote *If you choose to vote these shares in person at the meeting, you must request a “legal proxy.” To do so, please follow the instructions at www.ProxyVote.com or request a paper copy of the materials, which will contain the appropriate instructions. Please check the meeting materials for any special requirements for meeting attendance. Smartphone users Point your camera here and vote without entering a control number Your Vote Counts! FLASHID-JOB# For complete information and to vote, visit www.ProxyVote.com Control # Ricky Campana P.O. Box 123456 Suite 500 51 Mercedes Way Edgewood, NY 11717 148,294 322,224 1 OF 2 30# Hextone, Inc. P.O. Box 9142 Farmingdale, NY 11735 XXXX XXXX XXXX XXXX BORGWARNER INC. 2026 Annual Meeting Vote by April 28, 2026 11:59 PM ET You invested in BORGWARNER INC. and it's time to vote! You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy material for the shareholder meeting to be held on April 29, 2026. View the Notice & Proxy Statement, Annual Report on Form 10-K online OR you can receive a free paper or email copy of the material(s) by requesting prior to April 15, 2026. If you would like to request a copy of the material(s) for this and/or future shareholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy. Vote in Person at the Meeting* April 29, 2026 9:00 AM EDT 3850 Hamlin Road Auburn Hills, Michigan, 48326

Voting Items Board Recommends THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming shareholder meeting. Please follow the instructions on the reverse side to vote these important matters. Vote at www.ProxyVote.com FLASHID-JOB# Control # XXXX XXXX XXXX XXXX 1.00000 322,224 148,294 Under New York Stock Exchange rules, brokers may vote “routine” matters at their discretion if your voting instructions are not communicated to us at least 10 days before the meeting. We will nevertheless follow your instructions, even if the broker’s discretionary vote has already been given, provided your instructions are received prior to the meeting date. BORGWARNER INC. 2026 Annual Meeting Vote by April 28, 2026 11:59 PM ET 1. Election of Directors Nominees: 1A Joseph F. Fadool For 1B Sara A. Greenstein For 1C Michael S. Hanley For 1D Shaun E. McAlmont For 1E Deborah D. McWhinney For 1F Alexis P. Michas For 1G Sailaja K. Shankar For 1H Hau N. Thai-Tang For 2. Approve, on an advisory basis, the compensation of our named executive officers. For 3. Ratify the selection of PricewaterhouseCoopers LLP as the independent registered public accounting firm for the Company for 2026. For 4 Approve the Amended and Restated BorgWarner Inc. 2023 Stock Incentive Plan. For 5 Vote on stockholder proposal regarding action by written consent. Against NOTE: Transact such other business as may properly come before the meeting or any adjournment or postponement thereof.