M281

Daimler joined the Renault–Nissan alliance in 2010, and its clearest product reached showrooms in 2014: the third-generation smart fortwo and forfour, engineered alongside the rear-engined Renault Twingo III and sharing most of their parts with it. The three-cylinder that Mercedes-Benz calls M281 is the alliance unit sold elsewhere as the Renault H4D and H4B — all-aluminum, twin-cam, port-injected, cast-in iron liners, canted over and buried beneath the load floor. The 999 cc version breathed normally; the shorter-stroke 898 cc turbo made 90 PS and 135 N·m, and Brabus later pushed it past 120 PS.

Badging is nearly all that separates it from a wide slice of the small-car market: the same engine is the Twingo III, the Clio IV 0.9 TCe, the Dacia Sandero and Logan 0.9 TCe, and the Nissan Micra K14 1.0. During development Daimler compared notes with Ford on the 1.0 EcoBoost, trading knowledge of its own lean-burn Euro 6 petrol work in return. When smart stopped building petrol cars in 2019 and went electric, the M281 became the last combustion engine the brand sold.