Western Star 4900 · 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 4900
| Fluid | How much | What to buy | Years | Source |
|---|---|---|---|---|
| Engine oil - DD15 (oil + filter)Change it: 35,000-75,000 mi by duty and oil analysis | 45.4 qt (43.0 L) | Detroit DFS 93K222 (CK-4) | 2010–2026 | Verified |
| Engine oil - DD13 (oil + filter)Change it: Per oil analysis program | 40 qt (38 L) | Detroit DFS 93K222 (CK-4) | 2017–2026 | Verified |
| Engine oil - Series 60 14L (pan + filter)Change it: 25,000-35,000 mi by duty | 40 qt (38 L) | API CI-4+ or CK-4, 15W-40 | 2000–2010 | Verified |
| Engine oil - Cummins ISX/X15 (pan + filter)Change it: 25,000-75,000 mi by duty | 43.4 qt (41.1 L) steel / 45.4 qt (43.0 L) aluminum | API CK-4, CES 20086, 15W-40 | 2000–2026 | Verified |
| Engine coolantChange it: Test at PM | Not verified - consult OEM service manual | Detroit Genuine Coolant / OAT extended life | 2000–2026 | Unconfirmed |
| DEF tankChange it: Fill at every fuel stop | 6, 13 or 23 gal (23, 49 or 87 L) | ISO 22241 DEF | 2010–2026 | Verified |
| Fuel tankChange it: - | 75-200 gal depending on option | ULSD, 15 ppm max | 2000–2026 | Verified |
Sources: Cummins X15 Quick Reference Guide 6553662; DD Engine Oil Capacities (DTNA), GHG14 table; DD Engine Oil Capacities (DTNA), GHG17 table; Detroit DD Platform Operators Manual Ch. 18; Series 60 Operator's Guide DDC-SVC-MAN-0039; Western Star 4900 technical sheet
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.