Which engines received an enhanced EGR cooler and coolant collector in the Gen 5 series?

In the Gen 5 series, the DD13 and DD15 engines are equipped with an enhanced Exhaust Gas Recirculation (EGR) cooler and coolant collector. This upgrade is fundamental as it improves the efficiency of the EGR system, allowing for better control of exhaust emissions and enhancing overall engine performance. The enhanced components help manage engine temperatures more effectively and contribute to the overall reliability and durability of the engine under various operational conditions.

The EGR cooler plays a vital role in the process by cooling the recirculated exhaust gases before they re-enter the combustion chamber, which helps in reducing nitrogen oxide (NOx) emissions. Coupled with the improved coolant collector design, these enhancements support more effective coolant flow and thermal management, ensuring optimal engine operation.

In contrast, other engine models mentioned in the options, like the DD14, DD16, and those not noted, have different specifications or configurations that do not include the same enhanced EGR cooler and coolant collector, making this choice specifically linked to the DD13 and DD15 engines within the Gen 5 lineup.