Audi's 189mph estate car - Telegraph Not content with its RS4 Avant, Audi has announced details of the new RS6, an estate car that's as fast as a Ferrari. The £77,000 RS6 is based on the A6 Avant, and retains that car's 565-litre boot (1,680 litres with the rear seats folded). However, Audi has filled the engine bay with a twin-turbocharged V8 that produces 552bhp and 516lb ft of torque. That's enough to propel this five-seater estate from 0-62mph in 3.9sec and, with Audi's "Dynamic Plus" option specified, a top speed of 189mph (the standard car is limited to 155mph). The £152,000 Ferrari California meanwhile has 490bhp, can travel from 0-62mph in 3.8sec and has a top speed of 193mph. The RS6's power is sent to all four wheels via an eight-speed automatic gearbox, and the engine also features the VW Group's cylinder on demand technology, allowing it to run on just four cylinders to save fuel. The switch between four and eight cylinders is said to happen within a few hundredths of a second and, along with a 100kg reduction in weight, helps the new RS6 be 40 per cent more fuel efficient than its twin-turbocharged V10 predecessor - it returns 28.8mpg on the EU Combined cycle. The RS6 also features adaptive air suspension as standard or optional sports suspension with active dampers, as well 390mm brake discs which can be upgraded to 420mm carbon-ceramic items. The standard equipment list will include parking sensors, satnav and a DAB radio when the Audi RS6 goes on sale in the new year. The first deliveries are expected in the summer.