ST205/75R15 vs ST225/75R15: Which Trailer Tire Does Your Build Need?
ST225/75R15 is about 20 mm wider and roughly 1.2 inches taller than ST205/75R15, and carries several hundred pounds more per tire at the same load range. Trailer manufacturers typically spec ST205/75R15 on single-axle utility trailers and step up to ST225/75R15 on tandem axles and heavier builds. The two sizes are not interchangeable without checking fender clearance and wheel width.
Side by side
| Spec (typical radial) | ST205/75R15 | ST225/75R15 |
|---|---|---|
| Section width | ~205 mm (8.1") | ~225 mm (8.9") |
| Overall diameter | ~27.1" | ~28.3" |
| Common load ranges | C, D | D, E |
| Typical rim width | 5–6.5" | 6–7" |
| Typical use | Single-axle utility, landscape, small enclosed | Tandem car haulers, larger enclosed, heavier utility |
Exact capacity depends on the load range and inflation printed on the sidewall — always verify against the tire you're actually buying.
When the 205 is the right call
Lighter single-axle builds where the certification plate calls for it. It's cheaper, fits narrower fenders, and at load range C or D covers most 2,990–3,500 lb GVWR trailers.
When to step up to the 225
- Tandem-axle builds where per-tire load climbs
- Car haulers and equipment trailers that see full-GVWR loading
- Any spec sheet that calls for load range D/E capacity with 15" wheels
The extra inch of diameter also drops revolutions per mile slightly — marginally cooler running on long Texas interstate pulls.
Can you swap one for the other?
Only if all three check out: (1) fender/frame clearance for the taller, wider tire; (2) wheel width in the approved range; (3) total capacity still meets the certification plate. When in doubt, match the plate.
For trailer manufacturers
We keep both sizes — tires and mounted tire-and-wheel assemblies — in our Dallas warehouse for production-line supply across Dallas–Fort Worth. Request factory supply pricing or see how our dealer program works.