F-150 Axle Ratio Towing
Your axle ratio can materially change GCWR and maximum loaded trailer weight, but the “best” ratio depends on your engine, cab/bed, wheelbase, drivetrain, and tow equipment.
On the 2025 F-150 towing selector, Ford shows different tow ratings across axle ratio rows (including 3.15/3.55 groupings and 3.73 listings), with big swings by configuration.
📊 Comparison table (what each ratio is best for)
| Axle ratio | Best for | Practical takeaway |
|---|---|---|
| 3.15 | Daily driving + light towing | Lower engine RPM at cruise, but you typically give up towing headroom compared to “tow-focused” specs (depending on your configuration). |
| 3.55 | Balanced tow + daily use | The most “middle ground” choice, and commonly paired with tow equipment paths in Ford’s towing documentation. |
| 3.73 | Heavier towing | Often the “tow-first” option, and in Ford’s selector tables you’ll see higher tow numbers on some 3.73 lines for certain builds. |
Important: It is not enough to say “3.73 tows more.”
Ford’s published numbers change by wheelbase, 4×2 vs 4×4, cab, and engine.
🔧 What an axle ratio actually does (in plain English)
A higher numeric ratio (example: 3.73 vs 3.15) multiplies torque more aggressively at the wheels.
That generally helps the truck start moving under load and hold gears more confidently when towing.
A lower numeric ratio typically cruises at lower RPM.
That can feel smoother and may help efficiency, but it can reduce towing headroom depending on the rest of the build.
Ford’s towing selector tables operationalize all of this by changing GCWR and max trailer weight by axle ratio and configuration.
🧮 Real Ford examples from the 2025 towing selector
These are specific lines from Ford’s 2025 Trailer Towing Selector to show how axle ratio changes outcomes.
Example 1: 2.7L EcoBoost shows a large jump to 3.73 in some configs
Ford lists the 2.7L GTDI V6 with a 3.15/3.55 grouping and multiple tow ratings (example line includes 7,400 lbs in a listed configuration).
Ford also lists a 3.73 axle ratio line where the table shows 8,400 lbs in a listed configuration.
Takeaway: On some 2.7L builds, moving to a tow-focused axle ratio can create meaningful towing headroom.
Example 2: 3.5L EcoBoost uses different ratio rows (and you must match the exact row)
For the 3.5L GTDI V6, Ford lists axle ratio rows including 3.31, 3.55, and a 3.73 row.
Ford also shows the highest conventional tow ratings on the 19,400 GCWR line (including 13,500 lbs in a listed configuration), and ties those top outcomes to required equipment notes.
Takeaway: On 3.5L trucks, you cannot assume the ratio alone tells the story—use the selector line that matches your exact truck.
Example 3: 5.0L V8 has multiple axle ratio rows, and the “best” depends on the specific listing
Ford lists 5.0L V8 entries that include axle ratios such as 3.15, 3.31, and 3.73, with tow ratings that vary by wheelbase/drivetrain lines.
Takeaway: Even within one engine family, the top trailer number can move up or down based on the rest of the truck build, not just the axle ratio.
🔍 How to find your axle ratio on your truck (fast)
If you do not know your axle ratio, Ford instructs you to check the Safety Compliance Certification Label (driver door area).
Look for the word AXLE and a two-digit code.
Then use Ford’s axle code chart in the guide to map that code to the axle ratio.
⚠ Two towing rules Ford states clearly (do not skip)
1) No weight-distribution hitch means a 5,000-lb limit.
Ford’s notes state: Do not exceed trailer weight of 5,000 lbs when towing without a weight-distribution system.
2) Tongue weight and payload control real-world towing.
Ford states trailer tongue load weight should be about 10% of total loaded trailer weight, and your added tongue weight, passengers, and cargo cannot exceed GVWR/GAWR.
✅ The decision guide (which ratio should you target?)
Choose 3.15 if…
You tow light and you care more about daily driving than maximum tow headroom.
You still must validate your exact tow rating using Ford’s selector, because towing varies by configuration.
Choose 3.55 if…
You want the most balanced “do-everything” spec.
You tow often enough that staying in the right selector rows matters, but you are not always chasing the maximum rating line.
Choose 3.73 if…
Your priority is towing heavier trailers with more margin.
Ford’s selector shows higher tow figures on certain 3.73 lines for specific builds (for example, 2.7L listings that reach 8,400 lbs in a shown configuration).
- 2025 Ford F-150 Towing Guide (official PDF) Ford VDM
- Ford towing calculator (VIN-based towing capacity lookup) Ford Motor Company
- F-150 towing capacity chart (by engine & axle)
- F-150 towing by engine: 2.7 vs 3.5 vs 5.0
- F-150 payload vs towing: the simple math
❓ FAQs
Does a 3.73 axle ratio always tow more than a 3.55?
Not always.
Ford’s published towing numbers vary by engine, cab/bed, wheelbase, and drivetrain, so you must match your exact selector line.
Where do I find my F-150 axle ratio?
Check your driver door certification label for the AXLE code, then map it using Ford’s axle code chart in the towing guide.
Can I tow over 5,000 lbs without a weight-distribution hitch?
Ford states you should not exceed 5,000 lbs of trailer weight when towing without a weight-distribution system.
What tongue weight should I plan for?
Ford states trailer tongue load weight should be about 10% of total loaded trailer weight, and that payload limits (GVWR/GAWR) must not be exceeded.
🏁 Conclusion
Axle ratio matters, but it is only one lever in Ford’s towing math. Ford VDM
If you want the correct answer for your truck, identify your axle code and then use Ford’s selector table or VIN tool to confirm the exact tow rating line that matches your build.
Like and comment with your engine, cab (Regular/SuperCab/SuperCrew), 4×2 or 4×4, wheelbase, and axle ratio, and I’ll tell you which towing-selector line you should be using from Ford’s guide, and visit us again truckreportgeeks.com