Delta II is General Motors' current compact car platform, which was developed by Opel in Germany. It is the successor to the GM Delta platform. Internally it is simply known as a new Global Compact Vehicle Architecture or GCV. The platform features a torsion beam rear suspension with optional Watt's link which improves vehicle handling; such configuration is used in the Opel Astra and some trim-levels of the American-market Chevrolet Cruze. This suspension is usually described as semi-independent, meaning that the two wheels can move relative to each other, but their motion is still somewhat inter-linked, to a greater extent than in a true independent rear suspension. This can mildly compromise the handling and ride quality of the vehicle. For this reason, some manufacturers have changed to different linkage designs. As an example, Volkswagen dropped the torsion beam in favour of a true IRS for the Volkswagen Golf Mk5, possibly in response to the Ford Focus' Control Blade rear suspension. Opel/Vauxhall have continued to use twist or torsion beam suspension. This is at a cost saving of €100 per car compared to multi-link rear suspension. Their latest version as used in the 2009-on Opel Astra uses a Watts linkage at a cost of €20 to address the drawbacks and provide a competitive and cost effective rear suspension. The Renault Megane and Citroen C4 also have stayed with the twist beam. The twist beam has been shown to suffer less from bush wear, than fully independent multi-link suspension, thus resulting in a virtually maintenance free rear suspension. GM chose this compact vehicle architecture for its first Voltec application, the Chevrolet Volt. Production began in November 2010 with the first Chevrolet Volts delivered to retails customers in December 2010
General Motors introduced its new global platform named D2XX flexible platform in August 2012. The new platform was mainly engineered by GM's former German subsidiary Opel in Rüsselsheim. According to GM the company invested US$220 million for the all new D2XX platform. The platform was developed for compact vehicle architecture, replacing both Delta II and the midsize crossover GM Theta platform. Vehicles that used the new platform included:
In 2015 Pan Asia Technical Automotive Center, GM's joint development center with SAIC, revealed their own simplified variant of D2XX, known as the "GM-PATAC K" platform. The following vehicles use this variant of the platform, none of which are sold in the United States:
