The 420 Sedan Bridge even inherited spirited performance, courtesy of the MerCruiser-Cummins synergy. My test boat was equipped with a pair of optional 446-shp (480-bhp) 480C-E Cummins diesels, along with with the optional SmartCraft electronic monitoring system. Putting her through her paces on a dead-calm day&mdasah;great for boating but not for a sea trial&mdasah;I posted a 30.1-knot (34.7-mph) WOT speed, and at 2000 rpm I measured a 20.7-knot (23.8-mph) cruising speed. When I nudged her up to 2250 rpm, she clipped along at 25.1 knots (28.9 mph). With 350 gallons of fuel, she should have a 272-NM range at slow cruise and 250-NM range at fast cruise. [links]