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This Mercedes-AMG A45 S has a 201mph top speed

Mercedes-AMG’s latest A45 is one the most potent hot hatches around, but Posaidon has taken it a step further

Affalterbach’s latest A45 has the world’s highest specific output production four-cylinder, making it one of the most capable hot hatches on the market today. A number of tuners have applied an ECU tune to find even greater numbers, but German firm Posaidon has taken matters up a notch further with its A45 RS 525.

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416bhp and 369lb ft of torque are what you receive from the factory in the A45 S, numbers that wouldn’t have looked out of place in a supercar not too long ago. Thanks to the brand’s 4Matic all-wheel-drive system and an eight-speed dual-clutch transmission, this power is translated into a 3.9sec 0-62mph time and a 168mph top speed. 

> 2019 Mercedes-AMG A45 S review - a new high water mark?

This, however, is not enough for some. In Posaidon’s two-tier upgrade, out goes AMG’s turbocharger and in goes an uprated unit, helping to increase efficiency and hurl even more boost at the 2.0-litre four-pot. To ensure everything works in harmony, both the engine and gearbox see software tweaks, with the final result being an output of 518bhp and 443lb ft of torque. Yes, from a 2-litre four cylinder...

Thanks to an extra 102bhp and 74lb ft over factory, the ‘A45 RS 525’ will cover the 0-62mph sprint in a quoted 3.4sec, sooner than even the £188,345 AMG GT R Pro. More impressive still is its monumental 201mph (quoted) top speed, a number that also exceeds that of the brand’s aforementioned flagship. 

For those that would like to see their engine in one piece for a little longer, more conventional ECU tunes can also be had, bringing output to a still-bonkers 459bhp and 413lb ft of torque, enough for a 3.6sec 0-62mph time and 198mph top speed. 

Later this year, the brand will launch its own high-performance braking system to help tame the additional power, with a new exhaust system, uprated turbocharger and full-carbon 20” wheels, weighing just 4.9kg a piece, also in the pipeline. 

Though details are yet to be revealed, the tuner has also said that ‘further projects’ are under development, with a more powerful ‘plus’ model to be released at a later date. Let’s hope it includes a reinforced grab handle...

All of the above can be applied to any of Mercedes-AMG’s new 45 models sporting the M139 unit. Pricing can be had upon application.

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