Mercedes-AMG A45 S Plus (W177) walkaround: DCT 8G gearbox

Mercedes-AMG A45: mechanical breakdown

A 69-second dealer walkaround

A 69-second walkaround of an A45 S Plus, captioned with an asking price of £42,250. The caption names no parts and no events. The S is the version most markets receive: a 2.0-litre M139 rated at 421 PS and 500 Nm, with 0-100 km/h in 3.9 s.

DCT 8G shift behavior and its flaw

Power goes through the AMG Speedshift DCT 8G, an 8-speed dual-clutch gearbox, behind an M139 that revs to 7,200 rpm. The 3.9 s to 100 km/h in the S 4MATIC+ is a figure for the whole drivetrain, and the gearbox is the part that sets how quickly each ratio change is completed. The known flaw is at the other end of the speed range. Low-speed jerkiness is a documented weak point of this DCT, especially in early cars, and it shows up in stop-start traffic and parking maneuvers rather than at full throttle. Owners of later cars report it far less often.

Remap, GPF delete and intercooler trade-offs

A remap is the usual first step on the M139, because software alone gives large gains in power and torque. The cost lands on the DCT 8G and the 4MATIC+ driveline, which carry the extra load, and it can void the warranty. The second change is a downpipe with GPF delete. On European cars the particulate filter strongly mutes the exhaust, so removing it makes the car louder and leaves more headroom for tuning, but it is usually not road-legal and can fail an emissions inspection. An uprated intercooler targets repeated runs: the turbo keeps lower intake temperatures, so power stays consistent from one pull to the next. It costs money and installation time.