Cummins details 2027 Twin Module diesel aftertreatment for X10 and X15
Cummins has outlined its Twin Module aftertreatment system for 2027 X10 and X15 diesel engines, combining familiar catalysts and filters with electric heating and parallel-flow SCR to meet EPA 2027 emissions rules.
- 2027
- X10 and X15
- 48-volt
- Two
What Happened
Cummins' Twin Module is the company's diesel aftertreatment architecture for its X10 and X15 diesel engines under U.S. Environmental Protection Agency 2027 emissions requirements. It is designed and optimized for those engines in EPA 2027 applications. The system treats exhaust after combustion to help the engine system meet emissions requirements while supporting durability, efficiency and real-world performance.
Aftertreatment treats exhaust after it leaves the engine, using catalyst and filter technologies to reduce emissions, including particulate matter and nitrogen oxides, before exhaust exits the vehicle. Twin Module builds on Cummins' familiar aftertreatment foundation: a diesel oxidation catalyst, a diesel particulate filter, selective catalytic reduction and single diesel exhaust fluid dosing. It keeps those proven building blocks while adding new technologies for 2027.
- Diesel oxidation catalyst, diesel particulate filter, selective catalytic reduction and single DEF dosing
- Two-assembly layout, updated catalyst technology, electric heating and parallel-flow SCR
The updates are meant to help the system manage emissions during cold starts, low-load operation and other real-world duty cycles; low-load operation means the engine is running but not working as hard, which can make exhaust temperatures lower. Twin Module is delivered as two main catalyst assemblies, a DPF assembly and an SCR assembly, which contain the filters and catalysts used to treat exhaust. This layout gives OEMs more flexibility as they package the aftertreatment system into different chassis designs. Twin Module uses single DEF dosing, with DEF injected once in the body mixer, a section designed to help mix DEF with exhaust before it reaches the SCR system.
- Electric heating helps the aftertreatment system reach the right operating temperature faster, especially during cold starts and low-load operation, because catalysts need heat to work effectively.
- Twin Module's electric heating is powered by a belt-driven 48-volt alternator.
- Parallel-flow SCR routes exhaust through the SCR system in parallel paths rather than one longer path, helping maximize NOx conversion and heat retention while reducing total system length and backpressure, or resistance to exhaust flow.
Twin Module combines familiar aftertreatment architecture with service-friendly updates and is designed to help meet 2027 requirements while preserving service familiarity where possible. Heater modules have no service intervals, but technicians may need to remove them for other maintenance, such as cleaning or replacing a DPF; V-band clamp connections, removable band-style clamps, help technicians access the heater modules. Cummins says Twin Module is designed to keep DPF service intervals unchanged even as emissions requirements become more stringent. Technicians should follow the latest Cummins service information, training and procedures for the engine and aftertreatment system they are servicing because the 2027 system includes new architecture and electric heating.
Previously from Cummins Inc.
Earlier in October 2026, Cummins said tens of thousands of engines had already received updated diesel exhaust fluid calibrations under EPA guidance. Those calibrations give operators more time before power or speed reductions.
Background drawn from MotorClaw's earlier coverage of Cummins Inc.'s official releases.
Why this matters
It matters to OEMs packaging these engines and to technicians servicing them, because Cummins says Twin Module is designed to help meet EPA 2027 diesel emissions requirements while keeping DPF service intervals unchanged and preserving service familiarity where possible. The two-assembly layout is also intended to give OEMs more flexibility in different chassis designs.
Terms in This Story
- Aftertreatment
- Equipment that treats exhaust after it leaves an engine to reduce emissions.
- Diesel exhaust fluid (DEF)
- A fluid used in selective catalytic reduction systems to help reduce nitrogen oxides in diesel exhaust.
- Selective catalytic reduction (SCR)
- An exhaust treatment system that uses a catalyst and a reductant to reduce nitrogen oxides.
- Diesel particulate filter (DPF)
- A filter in the exhaust system that captures particulate matter from diesel exhaust.
Summarised from the linked release; details can be imperfect — always verify against the original source.