ElpiAuto235/45R17 vs 225/50R17
225/50R17 is 0.53″ (13 mm) taller than 235/45R17, a 2.1% difference in overall diameter — right at the edge of the ±3% band — fine on most cars, but check clearance at full lock and full suspension compression.
| Measurement | 235/45R17 | 225/50R17 | Difference | % |
|---|---|---|---|---|
| Overall diameter | 25.33″ | 25.86″ | +0.53″ | +2.1% |
| Section width | 9.25″ | 8.86″ | −0.39″ | −4.3% |
| Sidewall height | 4.16″ | 4.43″ | +0.27″ | +6.4% |
| Circumference | 79.57″ | 81.24″ | +1.67″ | +2.1% |
| Revs per mile | 796.3 | 779.9 | −16.4 | −2.1% |
| Revs per km | 494.8 | 484.6 | −10.2 | −2.1% |
Speedometer: with 235/45R17 as the original, 225/50R17 makes an indicated 60 mph really about 61.3 mph, and the axle sits ~0.27″ higher.
Reading this comparison
The overall diameter is what matters here: 225/50R17 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.