205/55R17 vs 225/45R18
225/45R18 is 3.0 mm taller than 205/55R17 in overall diameter (+0.5%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 225/45R18 fitted, the speedometer reads 100 km/h when you are doing 100.5 km/h.
Dimensions side by side
| 205/55R17 | 225/45R18 | |
|---|---|---|
| Overall diameter | 657 mm (25.9″) | 660 mm (26.0″) |
| Section width | 205 mm | 225 mm |
| Sidewall height | 113 mm | 101 mm |
| Rim | 17″ | 18″ |
| Revolutions per km | 484 | 482 |
| In stock | 24 tires from $108.00 | 95 tires from $112.00 |
What changes
- Overall diameter: 225/45R18 is 3.0 mm taller (+0.5%).
- Speedometer: reads 100 km/h at an actual 100.5 km/h with 225/45R18.
- 225/45R18 is 20 mm wider, so check clearance and the recommended rim width.
- Wheel size changes from 17″ to 18″: you need wheels in the new size.
- Choose a load index at least as high as the one on your door placard.
Vehicles that came with both sizes
Vehicles that use 205/55R17
Vehicles that use 225/45R18
See every alternate size for 205/55R17
Frequently asked questions
Can I use 225/45R18 instead of 205/55R17?
Usually, yes: 225/45R18 is within 3% of the overall diameter of 205/55R17 (+0.5%). Use wheels of the right size and width, match or exceed the original load index, and check clearance at full steering lock.
How much does the speedometer change between 205/55R17 and 225/45R18?
With 225/45R18 instead of 205/55R17, the speedometer shows 100 km/h when you are actually doing 100.5 km/h.
Which vehicles came with both 205/55R17 and 225/45R18?
Both sizes were original equipment, on different trims or packages, on the 2019–2022 Mercedes-Benz A220, 2017–2019 Volkswagen Golf, 2019 Volkswagen Golf Alltrack, 2011–2016 Mini Countryman, 2013–2016 Mini Paceman, 2011–2016 Mini Cooper.