The most powerful four-cylinder hot hatch is bowing out, and Euro 7 is why
A send-off in yellow, for an engine emissions rules killed
The Mercedes-AMG A 45 S has spent years as the benchmark answer to a simple question: how much power can you extract from a four-cylinder in a hatchback. The answer was a hand-built 421 hp, more than anyone else managed. Now it is ending, and this Final Edition is the send-off. The reason it is ending is the part worth understanding.
What the Final Edition is
The send-off is almost entirely visual. It gets 19-inch AMG forged wheels with yellow accents, yellow mirror caps and lower-body trim, 45 S door graphics and Dark Chrome door handles, along with both AMG Night Packages and the optional AMG Aerodynamics Package with its splitter, rear wing and diffuser. Inside there is yellow contrast stitching, embroidered 45 S headrests, a 45 S Final Edition console plaque and illuminated sill panels. It comes in a choice of paint finishes, costs around 67,965 pounds in the UK, roughly 2,500 pounds over the standard car, and there is no announced production limit.
What it is not
Mechanically it is a standard A 45 S. The hand-built 2.0-litre M139 turbo four still makes 421 hp and 500 Nm, driving through an eight-speed dual-clutch and 4Matic+ with torque vectoring, good for 0 to 100 km/h in 3.9 seconds and an electronically limited 270 km/h. There are no chassis, brake or power changes. This is a trim and paint edition, not a sharper car, and it is worth being clear about that up front.
Why it is really ending
The Final Edition exists because the M139 engine cannot be made to meet the incoming Euro 7 emissions standard. As a result both the A 35 and the A 45 S are being withdrawn. This is regulation retiring an engine, not a brand deciding a model has run its course, and it is the same pressure quietly reshaping performance cars across the industry. The most powerful production four-cylinder ever built is being legislated out rather than beaten.
What comes next
The nameplate is not dead. A fifth-generation A-Class arrives in 2028 on the MMA platform with hybrid and electric power, and a hot AMG version is expected to borrow the electric CLA 45's tri-motor setup, worth around 671 hp. On paper the successor will humble this car, but it will be a completely different machine: heavier, electric, and without the hand-built engine that made the A 45 S what it was. More power, less of the thing people actually loved.
The honest caveat
A cosmetic Final Edition sits a little awkwardly against how some rivals have handled their own goodbyes. Audi sent off versions of the combustion RS 3 with genuine chassis and braking hardware rather than just a colour and a badge. Marking the end of an engine this significant with a set of yellow accents feels like a lighter tribute than the car deserves, however good the yellow looks.
AutoNext Take
The A 45 S deserves its send-off, because it genuinely was something special: a hand-assembled four-cylinder making supercar-era power in a five-door hatch, built to a standard nobody else matched. That it is ending because of emissions law rather than a lack of buyers is the story of the affordable performance car in miniature, and it is a quietly sad one. The combustion super-hatch, the everyday enthusiast's dream car, is being switched off one model at a time.
The frustration is that the send-off itself is so thin. A car this important ending on a paint pack and a plaque, with no mechanical farewell, undersells what is actually being lost. If you want one for what it is rather than how it looks, buy the engine, not the yellow. That M139 is the part that will be remembered.
