C18 ACERT auxiliary/generator set engines incorporate a separate circuit aftercooling system (SCAC) for all configurations. The primary advantage of the SCAC systsem is reduced aftercooler corrosion since no sea water circulates through the aftercooler. Many other improvements on these engines also contribute to minimizing owning and operating costs. The IMO II compliant ratings are available with heat exchanger or keel cooled options. All major MCS type approvals are available from the factory.