Dually fitment is not just about what clears when the truck is empty. The real test is whether the tires still have proper clearance when towing, loaded, aired up, and driving in real conditions.
The biggest thing to watch is rear dual tire clearance. Two tires that look fine unloaded can get dangerously close once the truck is loaded.
Why Dually Clearance Matters
Dual rear tires should never touch.
If the tires contact each other under load, it can create heat, wear the sidewalls, and increase the risk of tire failure.
A good general target is:
| Clearance | What It Means |
|---|---|
| 1" unloaded | Ideal target for most towing setups |
| 3/4" unloaded | Often works, but depends on tire/load |
| 1/2" loaded | Minimum clearance we like to see under load |
| Touching | Not acceptable |
Tire brand matters too. A 12.5" or 13.5" tire from one brand may measure wider than another, especially if it has aggressive sidewall lugs.
Simple Dually Offset Explanation
Dually wheels use different offsets depending on position.
| Wheel Position | Common Offset Style |
|---|---|
| Front | Positive offset |
| Rear inner | Positive offset |
| Rear outer | Negative offset |
- Higher positive offset = wheel sits further inward
- More negative offset = wheel sticks further outward
- This works the same for both rear dually wheels (inner and outer).
General Fitment Notes
| Setup | Common Tire Range | Notes |
|---|---|---|
| Stock 17" wheels | 265/70R17 | Safe practical upgrade |
| 17" wheels with spacer | 285-width | More clearance, |
| 20" stock-height truck | 285-295 width | Common clean fitment |
| 20"+ lifted truck | 12.5"-13.5" wide | Must measure actual gap |
| Aggressive mud tires | Varies | Sidewall lugs reduce clearance |
For heavy towing, don’t chase the widest tire possible. Clearance, load rating, and proper air pressure matter more than looks.
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Real-World Dually Fitment Examples
Below are real dually setups showing the rear offsets, and measured dual tire gap at the closest spot.
 Tire sizes on paper do not always match real inflated width.
