OM622

The Daimler and Renault-Nissan co-operation produced few things as plainly stated as this one. The base engine is Renault's R9M 1.6 dCi, built at Cléon in France and finished at Bremen with Mercedes hardware around it: the company's own stop-start system, its own air-conditioning compressor and alternator, a specific dual-mass flywheel, and a control unit carrying Mercedes exhaust after-treatment. Like the R9M it came from, it runs steel pistons rather than aluminum — among the first passenger-car diesels anywhere to do so — with low-tension rings for less friction.

What it made possible mattered more than what it made. Because it sits transversely, it gave the W447 Vito of October 2014 the first front-wheel-drive layout in the model's history, taking 70 to 100 kg out of the lightest versions. In that form, detuned for van work, it powered the Vito 109 CDI at 65 kW and the 111 CDI at 84 kW, sitting beneath the in-house OM651 in the rear-drive models. Its longitudinal twin, the OM626, did the equivalent job in the W205 C-Class.