BMW M5 F10 BMW's 4.4-litre V8 lurks beneath the long bonnet and, courtesy of the Competition Pack, has a small power bump to 423 kW and 680 Nm of torque. The V8 is direct-injected and has two twin scroll turbos to make all that go. This is also the first M engine to use BMW's Valvetronic technology. The same engine is found in the X6 M but in the M5 has a higher compression ratio and higher turbo boost pressure. The claimed fuel economy is 9.9 litres per 100km, and while we saw closer to 13.5, this is quite an achievement given all the power on tap and how much we indulged in it. Handling the power's transfer to the road is a seven-speed DCT, driving the rear wheels only. Between the rear wheels is the fabled M Differential, which changes behaviour based on the drive mode selected with the iDrive controller. The M diff is electronically controlled and incredibly complicated, but it is of the limited slip variety and one of the most effective understeer-ki...