ElpiAuto225/45R17 vs 235/55R17
235/55R17 is 2.20″ (56 mm) taller than 225/45R17, a 8.8% difference in overall diameter — outside the ±3% band, so expect the speedometer to drift and check for rubbing before fitting.
The sidewall heights are very different — ride and steering feel will change noticeably even though the diameter is close.
| Measurement | 225/45R17 | 235/55R17 | Difference | % |
|---|---|---|---|---|
| Overall diameter | 24.97″ | 27.18″ | +2.20″ | +8.8% |
| Section width | 8.86″ | 9.25″ | +0.39″ | +4.4% |
| Sidewall height | 3.99″ | 5.09″ | +1.10″ | +27.7% |
| Circumference | 78.45″ | 85.38″ | +6.93″ | +8.8% |
| Revs per mile | 807.6 | 742.1 | −65.5 | −8.1% |
| Revs per km | 501.8 | 461.1 | −40.7 | −8.1% |
Speedometer: with 225/45R17 as the original, 235/55R17 makes an indicated 60 mph really about 65.3 mph, and the axle sits ~1.10″ higher.
Reading this comparison
The overall diameter is what matters here: 235/55R17 is the taller tire. It sets ride height, gearing and how far the tire travels per revolution — which is what the speedometer and odometer count. Width and sidewall change fit and feel (a wider tire needs a wider wheel and more clearance; a shorter sidewall sharpens steering) but not the gearing.
Figures are geometric estimates from the size codes; real moulded tires vary by brand by 1–3%. Confirm load rating, wheel width and physical clearance on your vehicle before fitting. To compare any other two sizes, use the tire size comparison tool; to decode one size and see what else fits its wheel, the tire size calculator.