Ford recommends using Motorcraft 5W-40 synthetic diesel engine oil that meets Ford’s WSS-M2C171-F1 specification and API CK-4 (or CJ-4 for older configurations, depending on the model year). This ensures proper lubrication and protection for the engine and its aftertreatment system.
The 6.7 L Power Stroke, used in Ford Super Duty trucks, depends on the right oil to safeguard the turbo, fuel-injection system, and diesel particulate filter. Specifications can vary by production year, so owners should verify the exact requirement in the vehicle’s owner manual or by checking with a Ford dealer.
Official oil specification for the 6.7 L Power Stroke
To align with Ford’s guidelines and industry standards, the recommended oil is a high-quality full-synthetic diesel engine oil that adheres to Ford’s specifications and API categories compatible with modern aftertreatment systems.
- Viscosity: 5W-40
- Type: Full-synthetic diesel engine oil
- Ford specification: WSS-M2C171-F1
- API category: CK-4 (CJ-4 may apply to older configurations; year-specific)
- Brand: Ford Motorcraft is the canonical option, but any aftermarket oil that explicitly meets WSS-M2C171-F1 and API CK-4/CJ-4 is acceptable
Before listing the core requirements, it helps to know what to look for on the bottle. The following items summarize the key criteria:
In short, the oil should be a 5W-40 synthetic diesel oil that meets Ford’s WSS-M2C171-F1 spec and the appropriate API category for your year model.
Year-by-year nuance
Because the 6.7 L Power Stroke has seen updates across production years, the exact API category can shift. General guidance given by Ford and aftermarket references is as follows, but you should confirm with your owner’s manual or a Ford dealer for your VIN:
- 2011–2016 models: Typically CJ-4 API category with Ford WSS-M2C171-F1
- 2017–present models: Typically CK-4 API category with Ford WSS-M2C171-F1
Note: Some oils marketed as FA-4 are aimed at newer engines with lower SAPS, but Ford’s listed requirement for the 6.7 L Power Stroke has traditionally centered on CK-4/CJ-4 compatibility with WSS-M2C171-F1. Always verify the exact specification for your exact model year and VIN.
How to verify oil compatibility in practice
When buying oil, check the label and product data sheet to ensure the following:
- Viscosity: 5W-40
- Meets Ford WSS-M2C171-F1
- API category: CK-4 or CJ-4 as appropriate for your year
- Brand: Ford Motorcraft or an aftermarket oil explicitly approved to meet the same Ford/API specs
If you’re unsure, consult your Ford dealer or reference your vehicle’s owner manual to confirm the exact specification required for your truck’s year and configuration.
Summary
For the 6.7 L Power Stroke, Ford’s recommended oil is a 5W-40 synthetic diesel engine oil that meets Ford WSS-M2C171-F1 and the appropriate API category (CK-4 for newer years, CJ-4 for older ones). Choose Motorcraft or another brand that explicitly lists these specifications on the label, and always verify the exact requirement for your vehicle’s year and VIN in the owner’s manual or with a Ford dealer.