Tier III compliance for MTU Series 4000

Representatives of several class societies tested the 20-cylinder version, which was awarded approval as being representative of the remaining versions. NOx emissions have been reduced by 75% compared to IMO Tier II limits and particulate emissions have been cut to 65% below the EPA Tier 3 limit.

MTU attributed the reduced emissions to advances in turbocharger, combustion and fuel injection technology, noting that an additional diesel particulate filter is not required. According to the company, improving the efficiency of the engines’ turbocharger has reduced fuel consumption by a further 5% compared with the predecessor model.

The engines are currently available from MTU as 12, 16 and 20-cylinder versions for a power range extending from 2,160-3,900kW, covering yachts and patrol boats. For work boats, including tugs and ferries, MTU will gradually be introducing the engines complying with IMO Tier III and EPA Tier 4 emission regulations onto the market as 12, 16 and 20-cylinder versions covering a power range from 1,119-3,220kW.

The integrated propulsion system and SCR treatment is designed for flexible installation and features a high power-to-weight ratio. Vessels can switch between IMO Tier II and Tier III modes during operation to comply with the emission requirements of the region in which the yacht is sailing.

The SCR system offers real-time NOx measurement both upstream and downstream to ensure that precisely the required amount of reactant is introduced regardless of the conditions.

MTU will continue to offer IMO Tier II versions of the Series 4000 engines.