Cummins X15N (natural gas, 2024+)
14.90L Inline-6 natural gas (CNG/LNG) • Cummins
About the Cummins X15N (natural gas, 2024+)
The Cummins X15N is the 15L natural-gas heavy-duty Class 8 engine launched 2024 — Cummins' largest-displacement natural-gas engine and the most powerful production NG truck engine in North America. Designed to give natural-gas fleets the same power and torque as diesel X15 (500 hp / 1,850 lb-ft) — closing the power gap that limited ISX12N adoption in long-haul applications. The X15N targets long-haul fleets that want to electrify their carbon footprint without going BEV/FCEV — particularly those with access to RNG.
Overview
The Cummins X15N is the 15L natural-gas heavy-duty Class 8 engine launched 2024 — Cummins' largest-displacement natural-gas engine and the most powerful production NG truck engine in North America. Designed to give natural-gas fleets the same power and torque as diesel X15 (500 hp / 1,850 lb-ft) — closing the power gap that limited ISX12N adoption in long-haul applications. The X15N targets long-haul fleets that want to electrify their carbon footprint without going BEV/FCEV — particularly those with access to RNG.
Specifications
- Manufacturer
- Cummins
- Displacement
- 14.90 liters
- Configuration
- Inline-6 natural gas (CNG/LNG)
- Fuel type
- CNG / LNG / RNG
- Horsepower
- 400–500 hp
- Torque
- 1450–1850 lb-ft
- Production years
- 2024–present
- Truck classes
- Class 8
- Applications
- Long haul, heavy haul, regional haul (natural gas)
Design and engineering
15L inline-6, same block architecture as diesel X15 but with spark ignition, natural-gas injectors, stoichiometric combustion + three-way catalyst. Targets diesel-equivalent power and torque outputs.
Generations and emissions eras
Reliability and longevity
Too new for long-term data. Architecture shares X15 block (proven), with natural-gas head and aftertreatment from ISX12N (proven 2018-present).
Common problems
Unknown — too new. Likely similar wear pattern to ISX12N (spark plugs, NG fuel quality).
Pros and cons
✓ Pros
- • 500 hp natural-gas — closes the power gap vs diesel
- • RNG capable for near-zero carbon
- • Cummins reliability heritage
- • Strong dealer support
⚠ Cons
- • Brand-new — unproven
- • NG infrastructure still gated
- • Premium pricing vs ISX12N