Audi RS3 Sedan vs. Mercedes-AMG CLA45: By the Numbers

Move over Mercedes-AMG CLA45, the upcoming Audi RS3 sedan is looking to take your crown.

The Mercedes-AMG CLA45 has existed in a class by itself in the U.S. An all-wheel drive performance sedan boasting 375 horsepower from a turbocharged 2.0L four-cylinder. There really hasn't been a direct competitor to it. But at the Paris Motor Show, Audi introduced the RS3 sedan. Boasting close to 400 horsepower and hitting 60 mph in a hair over 4 seconds, Audi is directly taking aim at the CLA45.

We can't help but wonder which one is better. Of course, the best way to answer this is to pit both of them in a comparison test. But with the RS3 not due here in the U.S. till next summer, we're going to be waiting quite a while for this answer. Instead, we're going to be doing some bench racing. Comparing the specs and performance figures of both models to see which one on paper is the better choice.

Power

We'll begin with the stalwart Mercedes-AMG CLA45. It boasts a turbocharged 2.0L four-cylinder producing 375 horsepower and 350 pound-feet of torque. Impressive figures for such a small displacement engine. Over at the Audi RS3, it comes with an all-new turbocharged 2.5L five-cylinder with 400 horsepower and 354 pound-feet of torque. Both engines come paired with seven-speed dual-clutch transmissions and all-wheel drive.

On paper, it seems the Audi has the advantage over the Mercedes. But when you take a look at the performance figures, it is a different story.

The Numbers

Let's begin with 0-60 mph times. Audi says the RS3 sedan will hit 60 mph in 4.1 seconds. With 25 more horsepower, it should leave the CLA45 in the dust. But the CLA45 hits 60 mph in 4.1 seconds, making for a dead heat. Run both models to their top speeds and the RS3 will pull away from the CLA45 - 174 vs. 167 mph. It should be noted these speeds can only be achieved if you opt for the performance packages. The standard models are limited to 155 mph.

Why are the RS3 and CLA45 in a dead heat in 0-60 times?

Our first suspicion was the delivery of torque. The RS3's 354 pound-feet of torque is available between 1,700 - 5,850 rpm. The CLA45's 350 pound-feet is available from 2,250 to 5,000 rpm. Audi has the wider spread, which should, in turn, make it slightly faster. So that wasn't the answer.

Could it be the RS3 sedan is heavier than the CLA45? It might, but Audi hasn't released technical details on the RS3 sedan. We do know that the turbocharged 2.5 four-cylinder used in the RS3 sedan is about 60 pounds lighter than the one used in the RS3 Sportback due to the engine block being made out of aluminum. But we won't know till Audi reveals all of the specifications of the RS3 closer to its launch.

Mercedes say the CLA45 weighs 3,450 lbs.

At the moment, we don't have a good answer.

Final Thoughts

If you were to ask us which one has the edge at the moment, we would say the Audi RS3. The higher top speed when equipped with the performance package gives it the slight edge. But this could change in the coming months with various outlets performing tests on the RS3. It may be that the CLA45 can hold off the RS3 for the honors when the dust settles.

But the performance figures give Audi the win over Mercedes.

Pic Credits: Audi and Mercedes-Benz