The 158,000m3 tankers are to be built by Hyundai Heavy Industries’ shipbuilding division (HHI-SBD).While there are already IMO Tier III-compliant vessels with EGR systems in service, the Suezmax newbuildings will be the first vessels with keel-laying after January 1st 2016 to be officially certified as complying with Tier III emission restrictions within existing North American NOx Emission Control Areas (NECAs) and the United States Caribbean Sea NECA, according to the provider of large-bore diesel and gas engines and turbomachinery.EGR is a NOx emission-control technology. MAN Diesel & Turbo originally developed, designed and manufactured the first EGR system for a two-stroke marine diesel engine for operation on a container vessel in service in 2010.In regard to introduction of its G-type engines, MAN Diesel & Turbo says that following efficiency-optimisation trends in the market it evaluated the possibility of using even larger propellers and thereby engines with even lower speeds for the propulsion of tankers and bulk carriers. Such vessels may be more compatible with propellers with larger diameters than designs used so far, and therefore able to facilitate higher efficiencies after adaptation of the aft-hull design to accommodate a larger propeller.It is estimated that such updated aft-ship designs with the G-series of engines offer potential fuel savings of some 4-7%, with a similar reduction in CO2 emissions, according to the company. Simultaneously, the engine itself can achieve a high thermal efficiency using the latest engine process parameters and design features, it says.