BMW 6-Series GC takes on the rivals
The days of the traditional boxy saloon are numbered. Meet the new breed of more-door supercoupe
Posted: 07 Aug 2012
The CLS350 CDI is a bit of a TG favourite, having beaten an A7 in a previous test and been super-popular in our long-term test garage. So why is an A7 back here? Because this one has the new BiTDI engine. And the new kid is the 640d Gran Coupe.
Forget the numbers on the bootlids. They don't correspond to engine sizes. The Audi is a 2.7, the others 3.0 litres, and all have six cylinders - V6 for Audi and Mercedes and straight-six for BMW. The Audi and BMW have the same eight-speed ZF auto 'box (replacing the seven-speed twin-clutch in lower-powered A7s), and Mercedes uses its own seven-speed auto. It's rear-drive for the Mercedes and BMW, quattro for the Audi. The Audi and BMW both use sequential twin turbos - a little one to get things moving at low revs, and a big one for more puff higher up. That gets them each to 313bhp, rudely healthy power for diesel engines.