Wärtsilä has introduced a new, "-D" version of its RT-flex50 low-speed marine engine type with a higher power rating and lower fuel consumption compared with the existing "-B" version. The maximum continuous power output of the RT-flex50 has been raised by 5.1% from 1660 to 1745 kW/cylinder (2260 to 2375 bhp/cylinder) in the "-D" version at the same running speed of 124 rpm. Thus, with five to eight cylinders in-line, the RT-flex50 in the "-D" version covers a power range of 6100-13,960 kW (8300-19,000 bhp) at 99-124 rpm. At the same time the brake specific fuel consumptions (BSFC) have been reduced by 2 g/kWh. Thus at the maximum continuous rating R1, the full-load BSFC has been reduced from 171 to 169 g/kWh.