Daum, S., Bhosale, S., Graf, G., and Ray, D., "Cost Efficient Tier 4 Final Solution for NRMM Engines up to 37 kW," SAE Technical Paper 2013-01-2466, 2013, doi:10.4271/2013-01-2466.
The increasingly stringent emission legislations provide a continuous challenge for the non-road market. In parallel to transient test cycles, increased emission durability as well as real driving emissions must be fulfilled. The enormous diversification of engines within the different power classes as well as the specific operation requirements regarding various duty cycles, robustness and durability, requires specific solutions to meet these legal limits.The publication shows a cost efficient, reliable and durable approach based on the example of a tractor engine jointly developed by Mahindra & Mahindra Ltd. (M&M) and AVL.It was found that a naturally aspirated (NA) application equipped with common rail and combined with cooled exhaust gas recirculation (EGR) is able to fulfill all legal Environmental Protection Agency (EPA) Tier 4 requirements with a minimum effort on the exhaust aftertreatment side by using only a diesel oxidation catalyst.In the paper the technical feasibility, the boundaries and challenges of such an application, as well as a trade-off between power density and technology for tractor engines in this segment are defined. The performance and emission reduction technology was been developed jointly by AVL & M&M and will be seen on M&M Tier 4 tractors in production.