Western Star 57X · fluids
Fluids & Fill AmountsHow much oil, coolant, DEF and gear oil this truck takes, and what specification to buy.
Set the year first
Then read the How much column as a refill quantity, not a dry fill. Fill to the dipstick or sight glass and treat the number as a starting point — a drain never gets everything out.
Fill amounts for Western Star 57X
| Fluid | How much | What to buy | Years | Source |
|---|---|---|---|---|
| Engine oil - DD15 Gen 5 (oil + filter)Change it: 35,000-75,000 mi by duty and oil analysis | 45 qt (43 L) | Detroit DFS 93K222 (CK-4) or 93K223 (FA-4) | 2023–2026 | Verified |
| Engine oil - DD13 Gen 5 (oil + filter)Change it: Per oil analysis program | 40 qt (38 L) | Detroit DFS 93K222 / 93K223 | 2023–2026 | Verified |
| Engine oil - DD15 total dry volumeChange it: - | 51.8 qt (49.0 L) | As above | 2023–2026 | Verified |
| Engine coolantChange it: Test at PM | Not verified - consult OEM service manual | Detroit Genuine Coolant / OAT extended life | 2023–2026 | Unconfirmed |
| Diesel exhaust fluid (DEF) tankChange it: Fill at every fuel stop | Order-specific | ISO 22241 DEF | 2023–2026 | Unconfirmed |
| Fuel tankChange it: - | Order-specific | ULSD, 15 ppm max | 2023–2026 | Unconfirmed |
| Transmission - Detroit DT12Change it: Not verified - consult OEM service manual | Not verified - consult OEM service manual | Detroit-approved synthetic ATF | 2023–2026 | Unconfirmed |
Sources: DD Engine Oil Capacities (DTNA); DD Engine Oil Capacities (DTNA), GHG17 table; Detroit DD15 Gen 5 spec sheet DDC-EMC-FLY-0120
Two ways to wreck an engine in five minutes
Overfilling an oil pan aerates the oil and can damage bearings. Running a cooling system low can crack a liner or a head before the gauge even moves. Fill slowly, then check the dipstick or sight glass twice.