The Mercedes-Benz S-Class (W221 generation) marks a strong comeback for the brand with the star in terms of build quality and reliability, following a highly criticized W220 generation. A flagship par excellence, it introduces cutting-edge technologies (night vision, Distronic Plus adaptive cruise control, dynamic massaging seats). The 2009 facelift brings LED daytime running lights, redesigned bumpers, and above all, a major update to the engines and the correction of early teething problems (notably on the petrol V6/V8s and the Airmatic suspension). Although generally very robust, the W221 remains a technological showcase whose maintenance requires a substantial budget.
The Mercedes S-Class W221 is an excellent luxury sedan, much better born than its predecessor. For a diesel purchase, the 3.0 V6 CDI (OM642) is the only reasonable choice, provided you check that the oil cooler seal has been replaced and the gearbox oil has been changed. Absolutely avoid the diesel V8 (S 420/450 CDI) and the 4-cylinder (S 250 CDI) which is too fragile. Favor a facelifted model (post-2009) which corrects the early teething problems of the electronics and engines. Plan a financial reserve of €2,000 to €3,000 to cover any potential whims of the air suspension or sensors.