BorgWarner Inc. is an American worldwide automotive industry components and parts supplier. It is primarily known for its powertrain products, which include manual and automatic transmissions and transmission components, such as electro-hydraulic control components, transmission control units, friction materials, and one-way clutches, turbochargers, engine valve timing system components, along with four-wheel drive system components.

The company has 60 manufacturing facilities across 18 countries, including the U.S., Canada, Europe, and Asia. It provides drivetrain components to all three U.S. automakers, as well as a variety of European and Asian original equipment manufacturer (OEM) customers. BorgWarner has diversified into several automotive-related markets (1999), including ignition interlock technology (ACS Corporation est.1976) for preventing impaired operation of vehicles.

Historically, BorgWarner was also known for its ownership of the Norge appliance company (washers and dryers).

The original Borg-Warner Corporation was formed in 1928 by the merger of Warner Gear, which itself was founded by Thomas Warner in 1901, and Borg & Beck founded by Charles Borg and Marshall Beck in 1903, Marvel Schelber Carburetor Co founded in 1905 by George Schebler and the Mechanics Universal Joint Co. The company was best known as the supplier of Warner Gear overdrive units for cars of the 1930s to the 1970s, and as the developer of Studebaker's three-speed automatic transmission introduced in 1950, along with 'Holley' brand Borg & Beck carburetors. Ford took up development of the transmission in Studebaker's place in 1955. The early Ford automatics are derivatives of the Borg Warner.

In the 21st century, the company changed the styling of its name from Borg-Warner to BorgWarner.

The company is also notable for co-developing a variable-geometry turbocharger with Porsche, the Variable Turbine Geometry (VTG) system, used in the 2007 911 Turbo. BorgWarner claims this technology will reach mainstream cars within 10 years. From 2002, Peugeot, Ford and Renault became major customers for the company's turbochargers with the Volkswagen Group on-board since 1999, choosing to exclusively use the BorgWarner K-Series turbochargers for their then-new 1.8T power plant.

BorgWarner supplies wet clutches and hydraulic modules for dual-clutch transmission systems. With their DualTronic technology, BorgWarner has gained contracts with European automakers that want to use dual clutch transmissions. The German automotive concern Volkswagen Group is BorgWarner's largest customer (by sales), and Europe is their largest market. Light vehicles (automobiles, car-derived vans, and light commercial vehicles) account for 72% of BorgWarner's total sales.

The company's world headquarters is in Auburn Hills, Michigan. Robert S. Ingersoll formerly served as the company's CEO and Chairman. BorgWarner's Powertrain Technical Center (PTC) is also based in Auburn Hills.

The BorgWarner Indianapolis 500 Trophy is presented to the winner of the annual Indianapolis 500 auto racing event; this has been provided by the company since 1936, as a legacy of Louie Schwitzer who won the first automobile racing event held at the facility, in 1909. It was announced by the Izod Indycar Series that BorgWarner has been selected as the official supplier for the turbochargers to be used in the 2.2L turbocharged engine formula for the series which took effect in 2012. On October 2, 2006, BorgWarner announced the purchase of the European Transmission and Engine Controls product lines from Eaton Corporation.

In 2002, BorgWarner Inc. was split into two key business divisions:

The following are subsidiary companies of the parent, BorgWarner Inc., and/or its primary divisions, and outline their respective products:

BorgWarner Inc. has the following production locations:

On April 12, 2005, BorgWarner won a 2005 Automotive News PACE Award at a ceremony in Detroit. The award recognized automotive suppliers for superior innovation, technological advancement and business performance.

Since 2012 season, BorgWarner currently supplies turbochargers for IndyCar Series with designation EFR7163. Since 1936 BorgWarner also sponsoring Indianapolis 500-winning presented trophy. Each year, the winning driver is presented with a miniature replica during a reception in January, about seven months after the race. Prior to the trophy's inception, the Wheeler-Schebler Trophy was awarded to the leader at the 400-mile mark, but was retired when car owner Harry Hartz claimed it three times. Since 2014 season, BorgWarner currently supplies turbochargers for Renault Sport Energy F1 V6 Turbo Power Units as an expertisement of hybrid turbochargers. BorgWarner also currently supplying turbochargers for all Renault R.S.01 cars since 2015 season.