Abstract
Fuel economy is one of the most important issues facing marine industries from the standpoint of both reducing greenhouse gas emissions and saving costs. Although engine manufacturers, ship builders, and ship owners have evaluated various means to improve the fuel efficiency of ships, there are only a few studies that deal with the contribution of marine engine lubricants to fuel efficiency. The authors investigated the influence of viscosity characteristics and additives (e.g. friction modifiers) in lubricants on the fuel efficiency of medium-speed trunk piston engines. Through laboratory tests, bench-and full-scale engine tests, it was found that optimized formulations with unprecedented low-viscosity improved fuel efficiency. The best formulation improved fuel efficiency by over 3% in full scale engine.
