It’s easy to build a sports car: You make it lightweight and powerful with the engine, transmission, and occupants positioned towards the center of the car for better balance. Tune the suspension to serve up gluttonous portions of grip and balance and presto: You’re done!
Performance sedans are another matter entirely, however. The engineers have to take a car that was packaged for comfort, convenience, and practicality and turn it into something special — something that makes the driver giggle on the right road at the right time, but that handles the daily grind as well as its mundane siblings. Currently, the BMW M5 sets the benchmark, although it’s anything but perfect. The transmission, the looks and the universally loathed iDrive system all detract from the M5 experience, not to mention the fact it’ll cost you close to $90,000 to put one in your driveway.
Although you might suspect its all-aluminum 4.2-liter V-8 is shared with the S4, other than the engine block it’s basically an all-new motor. There are new pistons and connecting rods; a new crankshaft together with its bearings; new cylinder heads; a free-flow twin exhaust system and the latest direct-injection technology to help it achieve its stratospheric 8250-rpm redline. Power peaks at an astonishing 414 hp at 7800 rpm and maximum torque is 317 lb-ft at 6000 rpm, although 90 percent of its twisty impulse is available between 2250 rpm and 7600 rpm so there are no real flat spots anywhere in its delivery.