John Deere Power Systems (JDPS) launched the PowerTech 6.8L marine propulsion engine towards the end of 2007. The 6068SFM75 offers up to 298kW (400hp) and is the newest marine engine offered by John Deere.
This new engine model meets EPA Tier 2 and EU emissions requirements and is MARPOL Annex VI compliant. The 6.8L marine engine is available in M1 through M5 ratings. The M5 rating is for marine applications that operate 300 hours or less per year and have load factors less than 35 per cent with 30 minutes out of each 8 hours of operation at full power. At M5, its highest rating, the 6.8L offers 298kW (400hp) at 2800rpm and consumes 77.6 liters of fuel per hour (20.5 gallons) at full load rated speed.
The M5 rating is most suitable for recreational applications, but the engine's four other ratings, which are suited for both recreational and commercial applications, also offer increased horsepower. The 6068SFM75 offers top-of-class fuel economy for every rating at both full load rated speed and typical cruising speeds.
The 6068SFM75 offers new features such as a 4-valve cylinder head, a high-pressure common-rail fuel system with pilot injection, a new seawater aftercooler, a heat exchanger with integrated top tank, a water-cooled exhaust manifold and turbo, as well as a viscous damper and a closed crankcase ventilation system.
In addition to its M5 rating, the 6.8L engine is available at other ratings suitable for fishing boats:
• M4: 265kW (355hp) at 2700rpm, 67 liters of fuel per hour (17.7 gallons) consumed at full load rated speed (M4 rating is up to 800 hours per year with load factors up to 40 per cent for applications that use full power for no more than one hour of each 12 hours of operation). Possible applications include inshore crew boats, charter fishing boats, pilot boats and dive boats.
• M3: 239kW (321hp) at 2600rpm, 60.2 liters of fuel per hour (15.9 gallons) consumed at full load rated speed (M3 rating is up to 2,000 hours per year with load factors up to 50 per cent for applications that use full power for no more than four hours out of each 12 hours of operation). Possible applications include coastal fishing boats, offshore crew boats, research boats and short-range ferryboats.
• M1: 186kW (249hp) at 2400rpm, 47.3 liters of fuel per hour (12.5 gallons) consumed at full load rated speed (M1 rating is for applications that may operate up to 24 hours per day at uninterrupted full power for more than 3,000 hours per year and have load factors of more than 65 per cent). Possible applications include line haul tugs and towboats and fish and shrimp trawlers/draggers.
