The Mercedes-AMG A45 S is the current king of the hot hatch world. In the S trim, it's 2.0-litre turbocharged four-cylinder is good for 416 bhp (310 kilowatts) and 369 pound-feet (500 Newton-metres) of torque, and even the base model has 382 hp (285 kW) and 354 lb-ft (480 Nm).
On paper, the odds are in the Mercedes' favour. The base model of the 911 uses a 3.0-litre, twin-turbo flat-six engine making 379 bhp (283 kW) and 331 lb-ft (449 Nm). In addition, it's rear-wheel drive in contrast to the A45's AWD layout.
Gallery: Mercedes-AMG A45 S versus Porsche 911 drag race
The real-world results are more illuminating, though. The numbers show both of them requiring 3.9 seconds to reach 62 miles per hour (100 kilometres per hour) from a standing start with launch control. While not evident in the figures, the video appears to show the Mercedes having a slight edge at lower speeds.
However, the 911 is able to cut through the air better than the A45 S. This becomes evident at 87 mph (140 kph) where the Porsche needs 6.9 seconds to reach that speed, versus 7.0 seconds for the Mercedes.
At the end of the 400-metre (1,312-foot) distance, the results are about the same. The Porsche crosses the line in 12.1 seconds at 117.13 mph (188.5 kph). The Mercedes is just a step behind by requiring 12.2 seconds at 115.08 mph (185.2 kph).
While not in this video, Which Car also did three separate 0-62 mph (100 kph) sprints with both vehicles. The A45 S completed the runs in 4.1 seconds, 4.0 seconds, and 3.9 seconds. In comparison, the Porsche hit that velocity in 4.1 seconds, 4.0 seconds, and 3.9 seconds. Yes, those are the exact same times.