Mack MP8 Engine Oil
The Mack MP8 takes Mack EOS-4.5 oil — a proprietary spec that goes beyond generic API CK-4.
Standard viscosity is 15W-40 CK-4; 2017+ GHG17 engines also accept 5W-30 FA-4 for improved fuel economy.
Capacity is 40 quarts (10 gallons) with filter. OEM drain interval is 25,000 miles on highway service.
OEM Oil Spec
Primary Grade
Oil Capacity
OEM Drain (Hwy)
Severe Service
FA-4 (2017+)
MP8 Quick Spec
| Engine | Mack MP8 |
| Displacement | 12.8L Inline-6 |
| Vehicles | Mack Anthem, Pinnacle, Granite |
| Applications | Line haul, regional, vocational |
| OEM Oil Spec | Mack EOS-4.5 (CK-4 equivalent + proprietary) |
| Primary Grade | 15W-40 CK-4 |
| FA-4 Grade | 5W-30 FA-4 (2017+ GHG17 only) |
| Cold Weather | 10W-30 CK-4 (above -4°F); 5W-30 FA-4 preferred |
| Oil Capacity | 40 qt / 10 gal with filter |
| OEM Drain | 25,000 mi highway; 15,000 mi severe |
| Extended Drain | 50,000+ mi with full synthetic + oil analysis |
What Is Mack EOS-4.5?
Mack EOS-4.5 (Engine Oil Specification 4.5) is Mack’s proprietary engine oil standard. It overlaps with API CK-4 but adds Mack-specific bench and engine tests that generic CK-4 oils do not have to pass. Running CK-4 oil that carries the EOS-4.5 mark protects your warranty; running plain CK-4 without EOS-4.5 approval does not.
EOS-4.5 sets tighter limits on oxidation stability, shear stability, and liner wear — areas where the MP8’s high-load duty cycles put oil under sustained stress. Mack maintains its own approved oil list; only oils on that list are considered fully compliant for warranty purposes.
- Tighter oxidation and nitration limits than base CK-4
- Stricter cam/follower wear protection thresholds
- Shear stability requirements for 12.8L high-load cycles
- Mack validates and publishes its own approved oil list
- EOS-4.5 FA-4 variant covers 2017+ GHG17 engines with 5W-30
Pre-2017 vs 2017+ MP8 — What Changes?
The 2017 GHG17 emission standards brought a revised MP8 tune and SCR system upgrades. That change also opened the door to FA-4 approvals. If you’re running a pre-2017 MP8, FA-4 is off the table — CK-4/EOS-4.5 only. On 2017+, Mack approved EOS-4.5 FA-4 (5W-30) for owners who want the fuel economy benefit of the lower-HTHS FA-4 category.
| Factor | Pre-2017 MP8 | 2017+ MP8 (GHG17) |
|---|---|---|
| OEM Spec | Mack EOS-4.5 (CK-4) | Mack EOS-4.5 (CK-4 or FA-4) |
| FA-4 Approved? | No | Yes — 5W-30 FA-4 only |
| Primary Viscosity | 15W-40 CK-4 | 15W-40 CK-4 or 5W-30 FA-4 |
| Cold Start Grade | 10W-30 CK-4 | 5W-30 FA-4 (preferred for cold) |
| Fuel Economy Benefit | Standard | Up to 1–3% with FA-4 5W-30 |
| Emission System | EGR + DPF | EGR + DPF + improved SCR |
Mack MP8 Oil Viscosity Grades
Three grades cover the MP8 under all operating conditions. Match the grade to your engine year, climate, and duty cycle.
Standard
The default Mack MP8 oil type. Works in all MP8 variants (pre-2017 and 2017+). Best for mixed-temperature operations above 10°F. Highest film strength — preferred for loaded vocational and severe-service applications.
2017+ Only
Mack EOS-4.5 FA-4 variant. Lower HTHS viscosity improves fuel economy by 1–3% versus 15W-40. Approved for 2017+ GHG17 MP8 only. Also the preferred cold-start grade for northern-climate operators on 2017+ trucks.
Cold Weather
Cold-climate alternative for pre-2017 MP8 when ambient temps stay above -4°F. On 2017+ engines, 5W-30 FA-4 is the better cold-weather pick. Use 10W-30 CK-4 on older MP8s that don’t qualify for FA-4.
Mack MP8 vs Volvo D13 — Same Engine Family
The Mack MP8 and Volvo D13 share the same engine platform. Both are 12.8L inline-6 diesels developed under the Volvo Group umbrella. In practice this means the oil specification requirements run parallel: the D13 requires Volvo VDS-4.5, which is Volvo’s proprietary equivalent to Mack’s EOS-4.5. Both specs sit on top of API CK-4 and track the same performance benchmarks.
- Mack MP8 = Volvo D13 platform — shared engineering, same block architecture
- Mack EOS-4.5 (CK-4) ↔ Volvo VDS-4.5 (CK-4) — parallel proprietary specs
- Mack EOS-4.5 FA-4 ↔ Volvo VDS-4.5 FA-4 — same for 2017+ fuel-efficient grade
- Oils approved for both specs exist (AMSOIL DME carries both EOS-4.5 and VDS-4.5)
- Do not assume cross-brand substitution without verifying both approval marks on the oil datasheet
More detail: Volvo D13 engine oil
Mack MP8 Oil Change Intervals
Mack publishes drain intervals by service classification, not just mileage. Match the interval to how the truck actually runs.
AMSOIL for the Mack MP8
AMSOIL’s Max-Duty line carries Mack EOS-4.5 approval and is rated for extended drain intervals up to 60,000 miles under the right conditions. Three options cover every MP8 variant.
AMSOIL Signature Series Max-Duty 15W-40 Synthetic Diesel Oil (DME)
Full synthetic CK-4 / SN formula with Mack EOS-4.5 and Volvo VDS-4.5 approval. Rated for 60,000-mile extended drains with oil analysis. AMSOIL’s independent testing shows 6× better wear protection than API CK-4 minimum standards. The right choice for any MP8, any year.
AMSOIL Signature Series Max-Duty 5W-30 Synthetic Diesel Oil FA-4
EOS-4.5 FA-4 approved for 2017+ GHG17 MP8 engines. Lower HTHS viscosity delivers measurable fuel economy gains on highway routes. Same synthetic base and extended-drain capability as the DME 15W-40. Best choice for 2017+ Anthems and Pinnacles running dedicated highway lanes.
AMSOIL Heavy-Duty Synthetic Diesel Oil 15W-40 (ADP)
Synthetic CK-4 formulation at a lower price point. Carries EOS-4.5 approval for MP8 warranty compliance. Solid choice for fleets managing cost-per-mile who still want synthetic protection and proprietary spec coverage. Use with standard OEM drain intervals.
Mack MP8 Engine Oil — FAQ
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The Mack MP8 requires oil that meets the Mack EOS-4.5 specification. The standard viscosity is 15W-40 CK-4. On 2017 and newer MP8 engines (GHG17 emissions), Mack also approves 5W-30 FA-4 under the EOS-4.5 FA-4 variant. Generic API CK-4 alone is not sufficient — the oil must carry the EOS-4.5 approval mark to meet Mack’s warranty requirements.
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Mack EOS-4.5 (Engine Oil Specification 4.5) is Mack’s proprietary engine oil approval standard. It builds on the API CK-4 baseline and adds Mack-specific tests for oxidation stability, cam wear protection, and shear stability. Oils must pass Mack’s own bench and engine test protocols to earn the EOS-4.5 approval. Mack publishes and maintains an approved oil list. Only oils on that list are considered fully warranty-compliant for the MP8 and other Mack EOS-4.5 engines.
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Only on 2017 and newer MP8 engines. Mack approved the EOS-4.5 FA-4 category (5W-30 FA-4) for GHG17-era MP8s to deliver improved fuel economy. Pre-2017 MP8 engines are not approved for FA-4 — use CK-4 EOS-4.5 only on those. FA-4 has lower high-temperature high-shear (HTHS) viscosity than CK-4, which benefits newer engines designed for it but can increase wear in older engines not engineered around that lower film thickness.
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The Mack MP8 holds 40 quarts (10 gallons) with a filter change. Always check the dipstick after filling and run the engine briefly before rechecking — the large oil system and filter volume mean the first reading after a fill can be slightly off. Use only EOS-4.5 approved oil when topping up or performing a full drain-and-fill.
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Mack’s OEM interval for the MP8 is 25,000 miles for highway service and 15,000 miles for severe service (vocational, stop-and-go, heavy idling, PTO use). With full-synthetic EOS-4.5 oil and regular oil analysis, some operators extend to 50,000 miles or beyond. Oil analysis is not optional at extended intervals — it’s the only way to verify TBN levels and catch wear metals or contamination before they cause damage.
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