PACCAR MX-13 ENGINE OIL
OEM SPEC, VISCOSITY GRADES & DRAIN INTERVALS
DIRECT ANSWER
The PACCAR MX-13 requires CK-4 oil. Primary viscosity: 15W-40. FA-4 is not approved for the MX-13. AMSOIL Signature Series Max-Duty 15W-40 (DME) and Heavy-Duty 15W-40 (ADP) both meet CK-4 requirements for the MX-13.
DISPLACEMENT
12.9L
HORSEPOWER
405–510 hp
TORQUE
1,450–1,850 lb-ft
OIL CAPACITY
~43 qt
with filter
OEM SPEC
API CK-4
PRIMARY GRADE
15W-40
OEM OIL SPECIFICATION
- PACCAR MX-13 requires API CK-4 as its base specification
- No proprietary PACCAR spec beyond CK-4 — unlike Cummins (CES 20086) or Volvo (VDS-4.5), PACCAR relies on the API CK-4 category directly
- FA-4 not approved
- Low-SAPS chemistry required for DPF/SCR compatibility
- Viscosity grades: 15W-40 primary, 10W-30 or 5W-40 for cold climates
TIP
PACCAR’s reliance on API CK-4 without a proprietary overlay means any CK-4 approved product qualifies — but not all CK-4 oils perform equally. Quality of the additive package, TBN, and oxidation stability determine how long the oil actually lasts.
VISCOSITY GRADE BY TEMPERATURE
| AMBIENT TEMP | GRADE | NOTES |
|---|---|---|
| Above 14°F (−10°C) | 15W-40 | Standard fleet grade |
| −4°F to 14°F | 10W-30 | Cold start improvement |
| Below −4°F (−20°C) | 5W-40 | Full synthetic required |
DRAIN INTERVALS
OEM STANDARD
25,000 mi
Highway, CK-4 approved oil
EXTENDED (OIL ANALYSIS)
50,000+ mi
AMSOIL program, verified highway
SEVERE SERVICE
15,000–20,000 mi
Reduce interval
⚠ WARNING
PACCAR does not publish extended drain approvals the way Cummins or Detroit do. Extended intervals require oil analysis verification for every application.
RECOMMENDED OILS — AMSOIL
Both products meet API CK-4 requirements for the PACCAR MX-13.
AMSOIL SIGNATURE SERIES MAX-DUTY
15W-40 Diesel Oil (DME)
Full synthetic. Highest protection and extended drain capability. Meets API CK-4.
AMSOIL HEAVY-DUTY SYNTHETIC
15W-40 Diesel Oil (ADP)
Full synthetic at a competitive price point. Meets API CK-4. Solid baseline for fleet use.