Semi Truck Tire Sizes
11R22.5 vs 295/75R22.5
The common mistake is treating 11R22.5 and 295/75R22.5 as the same tire because both fit a 22.5-inch wheel. They may be close in some applications, but close is not the same as approved.
The right comparison starts with dimensions, then moves to load capacity, dual spacing, loaded radius, and fleet policy.
What the numbers mean
11R22.5 is an older inch-based radial size format. 295/75R22.5 is a metric low-profile size format. Both include the rim diameter, but they express section width and profile differently. The 295 in the metric format is section width in millimeters; the 75 is the aspect ratio (sidewall height as a percentage of section width).
Typical dimension comparison
Typical values from published manufacturer data — exact figures depend on the specific tire brand and model. Confirm from manufacturer data sheets before making a substitution decision.
| Dimension | 11R22.5 (typical) | 295/75R22.5 (typical) | Why it matters |
|---|---|---|---|
| Overall diameter | 41.2 – 41.5 in | 39.4 – 40.0 in | Affects speedometer, gearing, ride height, and dual matching |
| Section width | 10.8 – 11.0 in | 11.4 – 11.7 in | Affects rim width approval and dual spacing clearance |
| Revolutions / mile | 494 – 500 | 515 – 524 | Different rolling circumference — do not assume odometers stay accurate |
| Loaded radius | 19.8 – 20.0 in | 18.9 – 19.3 in | Changes fifth-wheel and dock height relationship |
Key differences in practice
- The 11R22.5 is approximately 1.5 to 2 inches taller in overall diameter than the 295/75R22.5.
- The 295/75R22.5 is generally wider in section width despite being shorter in profile.
- Mixing the two sizes in a dual set causes diameter mismatch and load imbalance.
- A fleet moving from one to the other should verify speedometer accuracy, clearance, and load tables.
When a substitution may be considered
A substitution may be worth evaluating when a fleet is standardizing inventory, replacing older equipment specs, or moving to a tire line that is more available in the operating region. The evaluation should be done as a fleet decision, not one tire at a time in a roadside shortage.
The cleanest comparison uses the exact tire models being considered, not only the size names. Overall diameter, loaded radius, revolutions per mile, approved rim width, and load/inflation data can vary enough by model to affect the decision.
When not to substitute
- Do not mix 11R22.5 and 295/75R22.5 as dual mates.
- Do not replace one axle position and leave a mismatched rolling diameter on the same axle.
- Do not approve the change if rim width, dual spacing, or load capacity cannot be verified.
- Do not assume the speedometer, fifth-wheel height, or dock height will remain unchanged.
- Do not treat a tire-shop availability problem as proof that the replacement size is approved.
Size Verification Checklist
- Match by manufacturer data, not forum advice.
- Do not pair different rolling diameters in a dual set.
- Verify the wheel width is approved for the tire.
- Check dual spacing before changing drive or trailer positions.
- Recheck inflation guidance after any size change.
FAQ
Are 11R22.5 and 295/75R22.5 tires interchangeable?
They are not automatic substitutes. Both fit a 22.5-inch rim diameter, but they differ meaningfully in overall diameter, section width, loaded radius, and revolutions per mile. The 295/75R22.5 is typically about 1.5 to 2 inches shorter in overall diameter. This affects speedometer accuracy, gearing feel, fifth-wheel height, and dual matching. Any substitution must be confirmed against manufacturer data for the specific tires involved.
Which is bigger — 11R22.5 or 295/75R22.5?
The 11R22.5 is typically taller, with an overall diameter roughly 1.5 to 2 inches larger than the 295/75R22.5. The 295/75R22.5 is generally wider in section width. For dual assembly clearance checks, ride height, and gearing effects, overall diameter is the more important dimension to compare.
Does changing from 11R22.5 to 295/75R22.5 affect the speedometer?
Yes. A change in overall diameter changes revolutions per mile, which affects speedometer accuracy. The difference between these two sizes — roughly 20 to 30 revolutions per mile — is enough to produce a noticeable speedometer discrepancy. Confirm the actual diameter difference using manufacturer data and evaluate whether speedometer recalibration is needed before completing a fleet-wide size change.
Source Notes
- Manufacturer Michelin Truck Tire Data Book / Load and Inflation Resources
- Manufacturer Goodyear Commercial Truck Tire Resources
- Site note TruckTireGuide.com editorial notes
Editorial Review
TruckTireGuide.com editorial team
Maintained by an independent editor with fleet tire-program experience in regional Class 8 operations, supported by transportation regulatory research and commercial vehicle technical writing.
Pages are checked against public regulations, manufacturer resources, industry references, and conservative field practice. The site does not approve tires for service or replace qualified inspection.