Steer-by-wire

Space Drive, have been available since as early as 2003 for existing production vehicles. Several one-off vehicles and concept vehicles implemented steer-by-wire, such as the early-1990s Saab Prometheus, 1996 Mercedes F200, 2001 SKF Filo based on the Opel Zafira, 2003 General Motors Hy-wire, 2005 GM Sequel, 2007 Mazda Ryuga, and others. Schaeffler Paravan Technologie has provided steer-by-wire systems for one-off racing vehicles, for example: a steer-by-wire Porsche Cayman GT4 raced the 2020 24 Hours of Nürburgring and finished 2nd place in its class and 29th overall; a steer-by-wire Mercedes-AMG GT3 raced the following year using the same system and finished 16th overall. == Production combustion-engine vehicles ==

Coupled with traditional steering Rear-axle-only steer-by-wire may be coupled with traditional front wheel steering for conditional four-wheel steering, reducing turning radius at low speeds and increasing stability at high speeds. Purely mechanical four-wheel steering systems have been available in production cars since the mid 1980s, soon followed by computer-controlled systems in the late 1980s. Manufacturers implementing these systems included Citroën, Honda, Isuzu, Mazda, Mitsubishi, Nissan, Porsche, and Toyota. The popularity of four-wheel steering waned in the 1990s, with few models being offered in the early 2000s. Four-wheel steering systems reappeared in the late 2000s and 2010s in models by manufacturers including Acura, BMW, Nissan, Porsche, and Renault. Car manufacturers that have offered rear-axle steering in the 2020s include Acura, Audi, Bentley, BMW, Cadillac, Ferrari, General Motors, Genesis, Lamborghini, Lexus, Mercedes-Benz, Porsche, and Rolls-Royce. One such rear-axle-only steer-by-wire system couple with traditional front steering was Quadrasteer. It was developed by Delphi and was offered starting 2002 on some General Motors trucks. Despite favorable reception the system was discontinued in 2005 due to poor market penetration of only 17 percent of sales of the same model, partially due to lack of familiarity with the system and partially due to its $1000 mark-up. The front wheel steering uses electric power assist while an electronic system controls the rear wheel steering and turns them in the opposite direction of the front wheels when turning at lower speeds, and slightly in the same direction as the front wheels at higher speeds in order to increase stability. Without traditional steering . Steer-by-wire continued to be offered with the QX50 and QX55, and as late as 2022 it was being offered with the Infiniti Q60 coupe, which was discontinued that year. == Production electric vehicles ==

Production battery electric vehicles (BEVs) with rear-axle SbW coupled with traditional front-wheel steering include as of 2024 the Rolls-Royce Spectre, Lotus Eletre, Planned production vehicles with no-steering-column SbW as of 2023 include: Lexus RZ 450e, Nio ET9, Toyota bZ4X, As of 2023 Lotus, Mercedes-Benz, and Peugeot plan to offer no-steering-column steer-by-wire cars in the mid to late 2020s. ==References==