One Man, One Engine: Inside An Almost-sterile Assembly Line

The theory behind one person being the caretaker of a single-engine as it rolls down the assembly line is not new. Performance-machine makers have experimented with it from time to time.

- Mark Rechtin

But at AMG’s factory tucked into Affalterbach’s rolling hills northeast of Stuttgart, the philosophy is more than just an experiment—it’s the company’s core DNA.

Not to say you can’t modify DNA, as I saw in a tour of the performance tuner’s factory. Those familiar with AMG’s existing V-8 assembly line know it to be a controlled riot of overhead cables, parts bins, and old-school engine manufacturing processes. Yes, one person is in charge of each engine, but where the new M139 turbo-four will be built, it may as well be a semiconductor cleanroom.

The new M139 cranks out 387 hp in base form and 421 for the S model, which Ralph Illenberger, head of engine development for Mercedes-AMG, notes is “the highest power output per liter. … Even supercars cannot reach this.”