Mercedes-AMG A45 S (W177) vs Audi RS3: 0-100 km/h launch

Mercedes-AMG A45: mechanical breakdown

A45 S against the RS3 from standstill

Caption: A45 S against an Audi RS3, which is faster. The clip runs 9 s and covers a launch and acceleration. No modifications are named, so the figures to hold it against are the factory ones: the A45 S 4MATIC+ is rated at 421 PS and 500 Nm, with a claimed 3.9 s to 100 km/h. Those numbers come from a 2.0-litre M139 feeding an 8-speed AMG Speedshift DCT 8G and AMG Performance 4MATIC+ all-wheel drive. The brief gives no result for the race itself, so none is claimed here.

Rear axle clutches and Drift Mode

Behind the 4MATIC+ system, the rear axle carries AMG Torque Control. It uses two multi-plate clutches to split torque between the left and right rear wheels. An open differential shares drive passively; these clutches apportion it actively, so the car can send drive to one rear wheel on demand. That is the hardware that makes Drift Mode possible. The cost is complexity: two clutch packs sit downstream of the 8-speed dual-clutch gearbox, which already has a known weak point in low-speed jerkiness, especially on early cars. The 500 Nm of the A45 S goes through all of it.

Remaps, downpipes and intercoolers on the M139

Software comes first. An ECU remap gives the M139 large gains in power and torque with no hardware, but it can void the warranty and adds stress on the gearbox and drivetrain, which includes the dual-clutch and the rear clutch packs. Owners who want sound go to a downpipe or GPF-delete. European cars run a gasoline particulate filter that strongly mutes the exhaust, so removing it is louder and leaves more headroom for tuning; it is usually not road-legal and can fail an emissions inspection. An uprated intercooler lowers intake temperatures and keeps power consistent on repeated runs. It costs money and takes effort to install.