Here we have a real world dyno chart for the BMW F82 M4. It lets us compare and evaluate these numbers against what BMW has put out as official specs.
Official specs says that the M4 model makes 431 HP and 550 Nm of torque.
This dyno chart tells a slightly different story. It says that the M4 makes 465 HP between 6,000 and 7,000 RPM and up to 577 Nm of torque between 3,200 and 5,800 RPM. That is about a 35 HP and 30 Nm difference between the official numbers and the real world numbers.