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Cummins X15 (EPA 2024) specs
Oil drain, fuel filter, DEF filter and overhead (valve lash) adjustment intervals for the EPA 2024 Cummins X15, from Cummins' own quick reference guide.
Maintenance intervals by duty cycle (EPA 2024 X15)
Extreme severe duty (<3 mpg): oil drain every 4,500 mi, 500 hrs or 12 months. If idle + PTO time exceeds 40% on Short Haul, Normal or Light, use the next lower drain interval.
| Spec | Severe (3–4.9 mpg) | Short Haul (5–5.9) | Normal (6–6.9) | Light (7+) |
|---|---|---|---|---|
| Oil drain interval | 25,000 mi / 12 months | 50,000 mi / 12 months | 60,000 mi / 12 months | 75,000 mi / 12 months |
| Fuel filter(s) | 25,000 mi | 50,000 mi | 60,000 mi | 75,000 mi |
| DEF filter | 300,000 mi / 6,750 hrs | 300,000 mi / 6,750 hrs | 300,000 mi / 6,750 hrs | 300,000 mi / 6,750 hrs |
| Overhead adjustment (valve lash) | 500,000 mi / 10,000 hrs / 60 months | 500,000 mi / 10,000 hrs / 60 months | 500,000 mi / 10,000 hrs / 60 months | 500,000 mi / 10,000 hrs / 60 months |
| Engine brake assembly | 500,000 mi / 10,000 hrs / 60 months | 500,000 mi / 10,000 hrs / 60 months | 500,000 mi / 10,000 hrs / 60 months | 500,000 mi / 10,000 hrs / 60 months |
| Coolant system flush | Follow OEM coolant recommendations | Follow OEM coolant recommendations | Follow OEM coolant recommendations | Follow OEM coolant recommendations |
Source: Cummins Inc., Quick Reference Guide – Truck Maintenance and Operation 2024 – X15 (6553662, revised EPA 2024). Always confirm against your engine's serial-number documentation.
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