What is the axle ratio on a 6.7 PowerStroke?
There isn’t a single axle ratio tied to Ford’s 6.7 PowerStroke engine. The ratio depends on the specific Super Duty configuration, with common factory gear options around 3.73:1 and 4.10:1, and other ratios appearing on select builds.
How axle gearing interacts with the 6.7 PowerStroke
The axle ratio is part of the vehicle’s drivetrain gearing and determines how engine power is translated into rear-wheel speed. The 6.7L Power Stroke is the diesel engine used in Ford’s F-250, F-350 and F-450 Super Duty trucks, but the exact axle ratio is chosen by the factory based on the intended use (payload, towing, highway cruising) and the specific model year and trim. To know the exact ratio for a given truck, you’ll need to check the vehicle’s build information from the manufacturer or inspect its axle tag or VIN-derived data.
Common axle ratio options for 6.7L Power Stroke trucks
Below are the axle ratios most frequently encountered in 6.7-powered Super Duty models. Availability varies by year, body style (2WD vs. 4x4), and towing or heavy-duty packages.
- 3.73:1
- 4.10:1
- 3.55:1 (less common, used on some configurations)
- 4.30:1 (rare, in certain specialized/towing-focused builds)
Understanding these options helps explain differences in towing performance, launch feel, and highway RPM across different trucks equipped with the 6.7 PowerStroke. The exact ratio for a specific vehicle dictates how quickly the engine needs to spin to reach highway speeds and how well it maintains torque during climbs or when pulling heavy loads.
How to find the exact axle ratio on your 6.7 PowerStroke truck
To confirm the precise gearing of a particular vehicle, use these steps:
- Check the driver’s door placard or window sticker for the axle specification. It often lists the axle ratio (for example, “Axle: 3.73”).
- Inspect the differential–axle tag on the axle housing itself, which typically prints the exact axle ratio.
- Refer to the vehicle’s build sheet or VIN (Vehicle Identification Number) via Ford’s official tools or a dealer, which will include the axle specification.
- If you’re unsure, contact a Ford dealer with the VIN; they can pull the complete drivetrain configuration, including the axle ratio.
Why the axle ratio matters for performance
A higher numerical ratio (for example, 4.10:1) provides more torque multiplication and better performance when towing heavy loads, at the cost of higher engine RPM and reduced highway fuel efficiency. A lower numerical ratio (for example, 3.55:1) improves highway cruising efficiency and fuel economy but offers less low-end torque for steep grades or heavy trailers. The right ratio depends on how you use the truck—towing big payloads vs. everyday highway driving.
Summary
In short, the 6.7 PowerStroke does not have a fixed axle ratio. The most common factory options are in the 3.7x to 4.1x range, with exact numbers varying by year, trim, and configuration. To know the precise ratio for a specific vehicle, consult the door sticker, differential tag, build sheet, or VIN-based records from Ford or a dealership. This gearing choice influences towing capability, acceleration, and fuel economy, so identifying the correct ratio helps set expectations for performance.
