Evaluation of Noise, Vibration, and Harshness–Optimized Cylinder Deactivation on a Class 8 Diesel Truck with Impact on Emissions and Fuel Consumption: A Development of Strategy to Reduce Emissions and Fuel Consumption with Cylinder Deactivation While Providing an Acceptable Cabin Environment

Anticipated NO_X emission standards will require that selective catalytic reduction (SCR) systems sustain exhaust temperatures of 200°C or higher for effective conversion performance. Maintaining these temperatures becomes challenging during low-load conditions such as idling, deceleration, and coasting, which lower exhaust heat and must be addressed in both regulatory test cycles and day-to-day operation. Cylinder deactivation (CDA) has proven effective in elevating exhaust temperatures while also reducing fuel consumption. This study investigates a flexible 6-cylinder CDA system capable of operating across any combination of fixed firing modes and dynamic skip-firing patterns, where cylinders transition between activation states nearly cycle-by-cycle. This operational flexibility extends the CDA usable range beyond prior implementations. Data was primarily collected from a test cell engine equipped with the dynamic CDA system, while a matching engine in a 2018 long-haul sleeper cab served to identify firing patterns that minimize noise, vibration, and harshness (NVH). These patterns were subsequently validated under controlled conditions. Results showed a broader deactivation operating range and enhanced NVH characteristics. Despite accommodations for real-world NVH constraints, the flexible system delivered NO_X and fuel efficiency benefits comparable to those achieved by previous work performed on this engine.