Detroit DD15 Engine Oil
DFS 93K222 Spec, FA-4 Approved (GHG17), Drain Intervals
The Detroit DD15 GHG17 requires DFS 93K222 approved oil. FA-4 (5W-30) is preferred for GHG17 platforms for fuel economy. CK-4 15W-40 is also approved. EPA10 DD15 engines require DFS 93K218 and CK-4 only — FA-4 is not compatible.
GHG17 vs EPA10 — Different Engine, Different Oil
The DD15 spans two emissions platforms. Getting the spec wrong isn’t a minor issue — it’s an engine warranty and longevity concern.
DFS 93K222
- FA-4 5W-30 — preferred for fuel economy
- CK-4 15W-40 — fully approved, heavy-haul use
- IntelliServ oil life monitoring
- Drain interval: up to 50,000 km (31,000 mi)
DFS 93K218
- CK-4 15W-40 — required
- FA-4 is not approved for EPA10
- Lower HTHS tolerance — older clearances
- Conventional drain intervals apply
Do not use FA-4 oil in a pre-2017 EPA10 DD15. The lower HTHS viscosity is not compatible with older engine tolerances. FA-4 was engineered for GHG17 platform clearances. Using it in an EPA10 engine risks accelerated wear.
DFS 93K222 — What It Requires
DFS 93K222 is Detroit Diesel’s proprietary oil specification for GHG17 engines. It goes beyond what API CK-4 or FA-4 alone requires. Meeting API categories is a prerequisite — not a guarantee of DFS 93K222 compliance. Detroit maintains an approved product list.
- Requires API CK-4 or FA-4 as the base category
- Additional soot handling requirements beyond API base
- Enhanced oxidation stability for extended drain capability
- Low-SAPS formulation for DPF/SCR aftertreatment compatibility
- Validated against Detroit’s EGR and IntelliServ system requirements
IntelliServ is Detroit’s oil-life monitoring system. It calculates remaining oil life based on actual operating conditions — temperature, load, idle time, and more. The stated 50,000 km interval is the maximum with DFS 93K222 approved oil. IntelliServ may shorten that based on your duty cycle.
For the full technical breakdown of what DFS 93K222 requires, see the DFS 93K222 specification page.
AMSOIL Products for the Detroit DD15
Both products below carry DFS 93K222 approval for GHG17 DD15 engines. Select based on your platform year and operating preference.
Signature Series Max-Duty 5W-30
Primary recommendation for GHG17 DD15. FA-4 rating delivers measurable fuel economy vs CK-4. DFS 93K222 approved. Extended drain capable.
Signature Series Max-Duty 15W-40 (DME)
CK-4 approved for both GHG17 (DFS 93K222) and EPA10 (DFS 93K218) DD15 engines. Preferred by fleets in heavy haul or high-temp applications.
Detroit DD15 Oil — Common Questions
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GHG17 (2017+): DFS 93K222 approved oil. FA-4 5W-30 preferred for fuel economy. CK-4 15W-40 also fully approved.
EPA10 (2010–2016): DFS 93K218 approved oil. CK-4 15W-40. FA-4 is not compatible with the EPA10 platform.
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Model year is the primary indicator — 2017 and newer are GHG17. You can also check the emissions label on the engine or the DPF/SCR configuration. GHG17 engines have more sophisticated aftertreatment systems with SCR (selective catalytic reduction) in addition to DPF. If you need confirmation, check the Engine Serial Number with Detroit Diesel customer support.
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FA-4 provides a measurable fuel economy benefit on GHG17 Detroit platforms because the engine was engineered for lower HTHS viscosity. The improvement is real — typically 0.5–1.0%. For high-mileage highway fleets, it adds up over the course of a year. CK-4 15W-40 is not a wrong choice — it’s preferred in heavy haul and high-temperature operating profiles where the higher film strength matters more than the efficiency delta.
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Detroit Fuel Specification 93K222 is Detroit Diesel’s proprietary oil approval standard for GHG17 engines. It requires specific performance characteristics beyond API CK-4/FA-4 for soot handling, oxidation resistance, and aftertreatment compatibility. Meeting CK-4 or FA-4 alone is not sufficient — an oil must be specifically tested and approved against DFS 93K222. See the full DFS 93K222 specification breakdown.