Sulzer 12RTA96C low-speed marine diesel engines are made for the economic propulsion of large, fast container liners. The main aim of globally regulated slow steaming would be to reduce emissions of carbon dioxide (CO2), nitrogen oxides (NOx), sulfur oxide (SOx), and particular matters (PM) from shipping. A global regime limits the average speed of ships to 85% of their average speed in 2007. This result in slow steaming is already widely practiced because of changed market circumstances. Ship engines are designed for optimal combustion at specific loads near the high end of their rated power. Reducing load, as occurs with slow steaming, leads to less optimal combustion and an increase in specific fuel consumption. So, at lower speeds, even though a ship uses less fuel to go the same distance, it requires more fuel per unit of power delivered by the engines because combustion is not optimal.