Renntech

Renntech Inc. is an American automotive aftermarket engineering and tuning company founded in 1989 by Hartmut Feyhl. Based in Stuart, Florida, the company specializes in developing, manufacturing, and installing performance parts and complete vehicle upgrades for Mercedes-Benz, Mercedes-AMG, Maybach, and Mercedes-Benz Sprinter vehicles. Its work has also extended to selected Chrysler, Aston Martin, Smart, and other European luxury and performance vehicles. The company emerged from the transition surrounding AMG's integration with Mercedes-Benz. Feyhl had spent 12 years with AMG, working first on major performance programs including the Mercedes-Benz 300E 6.0 AMG, commonly associated with the “Hammer,” and later serving as technical director of AMG North America in Illinois. After the Mercedes-Benz and AMG relationship changed, Feyhl established Renntech to continue serving AMG's North American customer base while maintaining professional links with AMG figures Hans-Werner Aufrecht and Erhard Melcher. The name combines the German word “Renn,” meaning racing, with “technology.” Renntech's core business is performance development rather than mass-market vehicle production. Its programs can include engine calibration, turbocharger and supercharger development, engine construction, exhaust and intake systems, suspension and braking improvements, transmission upgrades, aerodynamic components, and complete vehicle conversions. The company has developed products for a broad range of Mercedes-Benz and AMG platforms, from compact roadsters and sedans to large SUVs, Maybach luxury cars, the Mercedes-Benz Sprinter, and high-output AMG models. Its engineering work is positioned at the intersection of motorsport technology, luxury customization, and road-car usability. Several high-profile projects helped establish the brand's visibility among enthusiasts and automotive media. The RENNtech E7.4RS became a prominent example of the company's large-engine performance work, while the 2006 “Chrome SL” show car attracted attention because of its SL-based design and chrome-finished exterior. Renntech vehicles and technical products have appeared in automotive magazines, specialist publications, blogs, and social-media coverage, reinforcing the company’s image as a specialist authority in Mercedes performance tuning. Renntech broadened its scope after the 1998 Daimler-Benz and Chrysler merger, developing performance upgrades for the Chrysler Crossfire. It later followed the use of Mercedes-derived V8 technology in Aston Martin vehicles by creating upgrades for Aston Martin models using the M177 engine family. Reported Renntech engine programs range from relatively compact 200-horsepower K4 builds for SLK and CLK applications to highly developed twin-turbocharged M177 packages reported at up to 1,198 horsepower for the Mercedes-AMG GT 63 four-door coupe. Beyond its main road-car tuning operation, the company operates RENNtech Motorsports, a racing division that has fielded a Mercedes-AMG GT4 in the SRO North American GT series. RENNtech Classics serves owners of early Renntech cars, pre-merger AMG vehicles, and collectible Mercedes-Benz automobiles, adding restoration and specialist support to the company's performance portfolio. Renntech Karting represents another extension of the brand, producing racing karts based around Aixro XR50 rotary engines. Renntech remains an independent specialist brand rather than a listed automaker or a subsidiary of Mercedes-Benz. Its reputation rests on engineering expertise, close familiarity with Mercedes-Benz platforms, bespoke high-performance builds, and the credibility associated with its founder's former AMG technical experience.

Renntech was established in 1989 by Hartmut Feyhl after his long career with AMG. Feyhl had spent 12 years at AMG, contributing to the development of the Mercedes-Benz 300E 6.0 AMG and later becoming technical director of AMG North America in Westmont, Illinois. The formation of Renntech followed the changing corporate relationship between AMG and Mercedes-Benz. The new company allowed Feyhl to continue supporting AMG-oriented customers in North America while preserving connections with AMG founders Hans-Werner Aufrecht and Erhard Melcher. The name Renntech combines “Renn,” the German term associated with racing, and “technology,” reflecting the company’s intended combination of competition-derived performance and engineering development. From its Florida base, Renntech developed a specialist business centered on Mercedes-Benz and AMG vehicles. Its activities covered the design and production of performance components as well as complete vehicle conversions. The company eventually worked across nearly the entire Mercedes-Benz AMG range, including sports cars, sedans, SUVs, luxury vehicles, and commercial Sprinter vans. Renntech’s public profile grew through technically ambitious and visually distinctive projects. The E7.4RS demonstrated the company’s approach to large-displacement, high-output Mercedes performance, while the 2006 Chrome SL show car used an SL platform with an unusually reflective chrome-painted finish. Such vehicles received attention from automotive publications and specialist media, helping establish Renntech as one of the better-known independent Mercedes tuning firms in the United States. The company expanded its vehicle coverage after Daimler-Benz and Chrysler combined in 1998. One result was the development of upgrades for the Chrysler Crossfire, a model linked to Mercedes-Benz engineering and production. Renntech later applied its Mercedes performance expertise to Aston Martin vehicles equipped with Mercedes-derived M177 V8 engines after Mercedes-AMG entered a strategic engine partnership with Aston Martin. This extended the company’s work beyond Mercedes-badged products while retaining a strong connection to its principal technical specialty. Renntech’s development work has included compact K4 engines for SLK and CLK applications and very high-output twin-turbocharged M177 programs for newer AMG vehicles. The company has also produced or publicized projects involving the Mercedes-Benz SLR McLaren, AMG GT, Maybach, Smart, Sprinter, and numerous Mercedes-Benz chassis generations. Its business model emphasizes bespoke engineering and specialist installation rather than standardized, high-volume aftermarket retail. The brand later developed complementary activities. RENNtech Motorsports functions as a dedicated competition division and has fielded a Mercedes-AMG GT4 in the SRO North American GT series. RENNtech Classics was created to support early Renntech vehicles, pre-merger AMG automobiles, and collectible Mercedes-Benz cars, broadening the company into preservation and specialist ownership services. Renntech Karting produces racing karts using Aixro XR50 rotary engines, including the SLR.Kart designation. Renntech continues to operate as an independent American performance company. Its identity is built around Hartmut Feyhl’s AMG background, long-term familiarity with Mercedes-Benz engineering, high-performance road-car development, motorsport participation, and support for historically significant AMG and Mercedes vehicles.

• 2013

  Aston Martin performance-development extension

  [1]Renntechen.wikipedia.org

  After Mercedes-AMG began a strategic engine relationship with Aston Martin, Renntech developed performance upgrades for Aston Martin vehicles using the M177 V8 engine family.

• 2009

  Expansion of Smart and Mercedes SUV programs

  [1]Renntechen.wikipedia.org

  The company’s listed projects include a Smart Fortwo program and the GLK350 Hybrid Pikes Peak project, alongside continued work on Mercedes SUV platforms.

• 2006

  Chrome SL show car

  [1]Renntechen.wikipedia.org

  Renntech presents the Chrome SL, an SL-based show car distinguished by its chrome-painted exterior and extensive media attention.

• 1998

  Expansion into Chrysler-related performance work

  [1]Renntechen.wikipedia.org

  Following the Daimler-Benz and Chrysler merger, Renntech expands its aftermarket activity to include performance upgrades for the Chrysler Crossfire.

• 1990

  190E 3.6L W201 program

  [1]Renntechen.wikipedia.org

  Renntech develops a performance project based on the Mercedes-Benz 190E W201, illustrating its early focus on substantial engine and chassis upgrades for Mercedes platforms.

• 1989

  Renntech is founded

  [1]Renntechen.wikipedia.org

  Hartmut Feyhl establishes Renntech in Florida after a 12-year career with AMG, creating a specialist company to serve the North American AMG and Mercedes-Benz performance market.

• RENNtech Motorsports enters GT competition

  [1]Renntechen.wikipedia.org

  The company operates a motorsport division that has fielded a Mercedes-AMG GT4 in the SRO North American GT series.

An independent, engineering-led performance specialist focused primarily on Mercedes-Benz and Mercedes-AMG vehicles, combining luxury-vehicle customization, high-output powertrain development, motorsport expertise, and collector-car support.

• Performance vehicle

  RENNtech E7.4RS

  The E7.4RS is one of Renntech’s best-known high-performance Mercedes projects. It represents the company’s early approach of combining extensive engine development with chassis and vehicle-system upgrades to create a substantially more powerful road car. The project helped attract attention from automotive media and enthusiasts and became an identifiable part of Renntech’s performance-car history.

• Show car · 2006

  Chrome SL

  Introduced in 2006, the Chrome SL was based on a Mercedes-Benz SL and featured an exterior finished in chrome paint. Its visual treatment made it a conspicuous show and media vehicle, demonstrating Renntech’s ability to combine mechanical tuning with highly customized presentation.

• Performance upgrade program

  Mercedes-AMG GT 63 4-Door Coupe programs

  Renntech develops high-output upgrades for the Mercedes-AMG GT 63 4-Door Coupe, including a twin-turbocharged M177 engine program reported at up to 1,198 horsepower. The work reflects the company’s focus on extracting substantially greater performance from current AMG powertrains while retaining the base vehicle’s luxury and grand-touring role.

• Automotive aftermarket · 1989

  Mercedes-Benz and Mercedes-AMG vehicle programs

  Renntech has engineered products and complete builds for a wide range of Mercedes-Benz and AMG platforms, including the C-Class, E-Class, S-Class, SL, SLK, CLK, CL, CLS, G-Class, GL, GLK, ML, Maybach, SLR McLaren, and Sprinter. Depending on the platform, programs may include engine work, calibration, forced induction, exhaust, suspension, braking, drivetrain, and exterior modifications.

• Race car

  RENNtech Motorsports Mercedes-AMG GT4

  The RENNtech Motorsports division campaigns a Mercedes-AMG GT4 in the SRO North American GT series. This activity gives the company a competition platform for demonstrating its motorsport capabilities and maintaining a direct connection between racing and its road-car engineering identity.

• Classic-car services

  RENNtech Classics

  RENNtech Classics provides specialist support for early Renntech vehicles, pre-merger AMG automobiles, and collectible Mercedes-Benz cars. The division broadens the brand beyond contemporary tuning into preservation, maintenance, restoration, and ownership support for historically significant performance vehicles.

• Racing kart

  SLR.Kart

  SLR.Kart is associated with Renntech’s karting activity. Renntech Karting develops racing karts using Aixro XR50 rotary engines, extending the company’s performance and motorsport engineering interests into a smaller competition vehicle format.

1. 1Renntechen.wikipedia.org