In terms of power output, the smallest engine here has the most horsepower, the A45 claiming 421 PS. Then comes the BMW M2 Competition with 410 PS and the Audi RS3 with 400. Therefore, everything tips the scale in favor of the Mercedes-AMG model. Even the acceleration times claimed by the manufacturers point in only one direction, with the AMG A45 hitting 62 mph in under four seconds. The RS3 can do the same. While the M2 Competition takes about 4-seconds flat to hit 62 mph. The biggest issue for the M2 Competition is putting the power down as a dyno run done by the guys from Motor1 – included in the video – revealed it had the most power.