2014 BMW M6 Cabriolet: Heavy Artillery Published on May 24, 2013 in Test Drives by Marc Lachapelle Photo: Marc Lachapelle The 4.4-litre V8 – codename S63Tü – produces 560 horsepower at 5,750 rpm and 500 lbs-ft of torque at only 1,500 rpm.
