As part of its efforts to create more environmentally-responsible products, Yanmar Marine USA Corp has endorsed the use of B5 biodiesel in its diesel engines. The eco-friendly diesel alternative has been approved for use across Yanmar's recreational marine line.

Compared to standard diesel fuel, B5 biodiesel can help reduce greenhouse gases and particulate matter, also known as soot, according to the engine maker. Producing less pollution, the blended fuel is 95 percent standard diesel with a maximum of 5 percent biodiesel. This B5 base conforms to stringent specifications outlined in ASTM D6751 or ISO EN14214.

Yanmar Marine offers a variety of pleasure boating engines approved for B5 biodiesel use. For the 9.1- to 125-hp range, the 1GM10, 2YM15, 3YM20, 3YM30, 3JH4E, 4JH3-HTE, 4JH3-DTE, 4JH4E, 4JH4-TE and 4JH4AE all accept the greener fuel. 

B5 biodiesel-compliant engines from 150- to 260-hp include the 4LHA-HTP, 4LH-HTZP, 4LHA-DTP, 4LHA-DTZP, 4LHA-STP, 4LH-STZP, 4BY150, 4BY150Z, 4BY180, 4BY180Z, 6BY220, 6BY220Z, 6BY260 and 6BY260Z.

For boaters who require more powerful 260- to 500-hp engines, the 6LPA-DTP, 6LPA-DTZP, 6LPA-STP, 6LPA-STP2, 6LPA-STZP, 6LPA-STZP2, 6LYA-STP, 6LY2A-STP, 6LY3-ETP, 6LY3-STP, 6LY3-UTP and 6CXM-STP are also compliant. In the 720- to 900-hp range, the 6SY-STP, 6SY-STP2, 6SY655 and 8SY-STP can all operate on B5 biodiesel.

With any biodiesel blend, there's a chance it may adversely affect certain metal, rubber and plastic engine fuel system components that aren't compatible with the eco-friendly alternative, according to Yanmar. The fuel can also produce higher moisture content, cold temperature flow and possible damage to painted surfaces.

Yanmar says consumers and boatbuilders should verify they are using biodiesel-compatible parts for all fuel supply and return systems, as failure caused by using non-compatible materials would void the engine warranty.