How do I tell what gear ratio my F150 has?
You can determine your F-150’s gear ratio by checking the rear differential axle tag, the vehicle’s window sticker or build sheet, or by decoding the VIN with Ford’s resources or your dealer. The ratio is a number (for example 3.55 or 4.10) that indicates how many times the driveshaft turns for one complete turn of the wheels.
Why the gear ratio matters
The gear ratio affects how your truck accelerates, pulls heavy loads, and cruises at highway speeds. A higher numerical ratio (like 4.10) typically improves towing and off-the-line response but can reduce highway fuel economy, while a lower ratio (like 3.31) tends to favor better highway efficiency and lower engine RPM at cruising speed.
Ways to find your F-150’s gear ratio
Read the differential axle tag on the rear axle
The most direct method is to inspect the axle tag mounted on the differential cover or nearby on the housing. The tag will usually list the axle ratio as a number (for example, 3.55, 3.73, or 4.10). This value is the gear ratio for the rear axle and is the most common reference used for daily driving and towing decisions.
- Safely lift and support the rear of the truck if needed to access the differential.
- Locate the differential cover at the center of the rear axle and look for a small metal tag or stamping on the housing.
- Read the line labeled “RATIO” or “AXLE” followed by a numeric value like 3.55, 3.73, or 4.10.
- If the tag is damaged, missing, or illegible, move to other verification methods.
Even if you don’t see a tag clearly, the rear axle is the primary source for the gear ratio, and there are reliable alternatives if the tag isn’t legible.
Check the door jamb sticker or window sticker
For many trucks, the axle ratio is listed on the Monroney window sticker for new vehicles or on the driver’s side door jamb label for some trim levels. Look for a line labeled “Rear Axle” or “Axle Ratio” with a numeric value (or a code that can be cross-referenced).
- In new vehicles, locate the window sticker; in some cases the door jamb label contains “Rear Axle” with a numeric value.
- If the sticker shows a code rather than a plain number, note the exact code and plan to cross-reference it with build materials.
- Be aware that some labels may show a rear-axle code that requires decoding against Ford’s documentation or a dealer.
This sticker is a quick, non-invasive way to confirm the ratio on many modern F-150s, especially when shopping new or certified pre-owned models.
Decode the VIN or access the build sheet
Your vehicle’s VIN can unlock detailed build information, including the axle ratio, through Ford’s official resources or a dealership. This method is especially useful for used trucks where labels may be worn or missing.
- Find the 17-character VIN on the driver’s-side dashboard or door-post placard, or in your vehicle documents.
- Use Ford’s official VIN decoder or contact your Ford dealer to pull the build data for that VIN. Some online VIN tools also provide axle-related details.
- Review the response for “Rear Axle Ratio” or “Drivetrain” specifications to confirm the exact number.
- If the decoder doesn’t display the axle ratio, request the build data card from the dealer.
VIN-based decoding leverages the truck’s original build configuration and is often the most reliable way to verify the exact ratio when physical labels aren’t accessible.
Manual calculation (advanced, as a last resort)
If you can’t access labels or a VIN decoder, you can infer the ratio by measuring gearing in action. This method is more involved and should be done with the vehicle safely supported and in a controlled environment.
- With the transmission in neutral and the transfer case in the appropriate mode (2WD or 4WD as applicable), rotate the rear wheels and observe the driveshaft rotation.
- Count the number of driveshaft revolutions for a known number of wheel revolutions (for example, 4–5 wheel turns).
- Compute the ratio as driveshaft revolutions per wheel revolution. Note that if you have a transfer case or front axle engaged, additional gearing may affect the math.
- Cross-check the result with other sources (axle tag, sticker, or VIN) to confirm accuracy.
Use caution with this method: working under a vehicle and manipulating driveline components can be dangerous. If in doubt, rely on official labels or dealer-provided data.
Common rear-axle ratios you may see in modern F-150s
Most Ford F-150 configurations use a rear axle ratio in the range of roughly 3.31 to 4.10, with exact values depending on engine, cab/bed configuration, 4x4 versus 4x2, and towing or payload packages. The following values are commonly observed:
- 3.31
- 3.55
- 3.73
- 3.92
- 4.10
Note: This list covers typical options but is not exhaustive. Always verify with the axle tag, sticker, VIN decode, or your dealer.
Summary
Knowing your F-150’s gear ratio helps you understand towing performance, fuel economy, and RPMs at highway speeds. The most dependable sources are the differential’s axle tag, the vehicle’s window or door stickers, and the VIN/build data from Ford or your dealer. If any label is unreadable or missing, use the VIN decoder or request the build data card to confirm the exact rear axle ratio. With the right information, you can tailor your truck’s performance to your needs and avoid mismatched towing or fuel economy expectations.
