After Volvo Penta introduced the D4 and D6 marine diesel engines in 2003, the engines quickly became known for their power and high-speed capabilities. Since then, more than 100,000 versions of the D4 and D6 have been installed in workboats, rescue boats, recreational boats and other vessels. The engines were so tough that Zodiac MilPro selected them for use in military boats that get dropped from airplanes.
Now, the Swedish company has completely redesigned the two engines to have more power, greater fuel efficiency, easier maintenance and lower operating costs. The company will offer three variants of the engines: IPS, Inboard and Aquamatic sterndrive. To go with the new engines, Volvo Penta also introduced a new sterndrive, an updated IPS drive and an upgraded Vessel Control System.
The powerplants have a redesigned engine management system, fuel injection system, turbo charger, supercharger, cylinder head, pistons, valves and crankshaft. The D4 now has a maximum output of 320 horsepower, while the D6 will boast as much as 480 horsepower. This represents a 10 percent increase at the top end over the previous designs.
You can read more about the new Volvo Penta engines here.