Delta was a General Motors compact front-wheel drive automobile and crossover SUV platform, originally developed by Opel Group. Delta was a successor to the Opel T platform; it also replaced J platform and the Z platform used by the Saturn S-Series. The platform debuted in the 2003 Saturn Ion. Vehicles of this platform generally carry the letter "A" in the fourth character of their VINs. Delta uses an independent suspension in front and Twist beam type in the rear. The Ecotec engine is widely used, as are a 4-speed automatic and 5-speed manual transmission. Delta Applications Former vehicles based on this platform: 2003–2007 Saturn Ion 2005–2010 Chevrolet Cobalt 2005–2009 Pontiac G5/G4/Pursuit 2006–2011 Chevrolet HHR Delta II Delta II was General Motors' global compact car platform, developed by Opel in Germany. It was 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 (marketed as compound crank) rear suspension with optional Watt's link which improves vehicle handling; such configuration is used with the Opel Astra, Cadillac ELR, Opel Cascada and higher 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 (IRS). 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. As noted, certain GM brands and models have continued to use the suspension setup, known variously as twist beam, torsion beam or compound crank suspension. This is at a cost saving of €100 per car compared to multi-link rear suspension. The version used on 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 Mégane 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