Mercedes AMG A45 RS 525

The Mercedes AMG A45 RS 525 is one of two tuning packages available from Posaidon for AMG’s mega hatch.

This is followed by the RaceChip announcement according to which it had unlocked nearly 500bhp from the already weapons-grade ‘M139’ engine in the Mercedes-AMG A45 S. Now, though, Posaidon has gone a step further.

Using a new engine map and an “upgraded turbocharger”, the A45 ‘RS 525’ churns out a ridiculous 518bhp and 443lb ft, up from the stock figures of 416bhp and 369lb ft.

Mercedes AMG A45 RS 525

Mercedes AMG A45 RS 525 Speed

With the added thrust and deletion of the electronic top speed limiter, the RS 525 can hit 201mph and will dispatch 0-62mph in just 3.4 seconds.

So, it’ll match a Porsche 911 Carrera 4S with Sport Chrono to 62mph, and edge it out by around 10mph at the top end.


Impressive, but perhaps a little excessive. If you agree, you might be more interested in the “lower-tier” option, which leaves the turbo alone and focuses on the software tweaks.

The result is 469bhp and 413lb ft, making for a still extremely impressive 0-62mph time of 3.6 seconds and a top speed of 198mph. Both of these solutions will be available for the CLA 45 S in May.

If instead, you want more than 518bhp, Posaidon will soon have a ‘plus’ version, along with beefed-up brakes, a cat-back sports exhaust and carbon fibre ‘Evolution One’ rims.