D2-50

The D2-50 is the naturally aspirated rating of Volvo Penta's 2.2-litre four-cylinder D2 block (84 x 100 mm bore and stroke, 23.3:1 compression), rated over a 2700-3000 rpm band. It arrived in the second quarter of 2017 as the emissions-compliant replacement for the D2-55, which had been withdrawn because it no longer met the current Recreational Craft Directive limits; the two are near-identical mechanically and share the same dry weight, so a D2-50 is best read as a re-certified D2-55 rather than a new engine. It is a mid-size sailboat auxiliary for roughly 35-42 ft cruisers, offered as shaft drive through an HS25A or MS25 gearbox or as a saildrive on the 130S/SR leg.