215/55R17 vs 225/45R18
225/45R18 is 8.0 mm shorter than 215/55R17 in overall diameter (−1.2%), 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 98.8 km/h.
Dimensions side by side
| 215/55R17 | 225/45R18 | |
|---|---|---|
| Overall diameter | 668 mm (26.3″) | 660 mm (26.0″) |
| Section width | 215 mm | 225 mm |
| Sidewall height | 118 mm | 101 mm |
| Rim | 17″ | 18″ |
| Revolutions per km | 477 | 482 |
| In stock | 83 tires from $108.00 | 95 tires from $112.00 |
What changes
- Overall diameter: 225/45R18 is 8.0 mm shorter (−1.2%).
- Speedometer: reads 100 km/h at an actual 98.8 km/h with 225/45R18.
- 225/45R18 is 10 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 215/55R17
Vehicles that use 225/45R18
See every alternate size for 215/55R17
Frequently asked questions
Can I use 225/45R18 instead of 215/55R17?
Usually, yes: 225/45R18 is within 3% of the overall diameter of 215/55R17 (−1.2%). 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 215/55R17 and 225/45R18?
With 225/45R18 instead of 215/55R17, the speedometer shows 100 km/h when you are actually doing 98.8 km/h.
Which vehicles came with both 215/55R17 and 225/45R18?
Both sizes were original equipment, on different trims or packages, on the 2016–2018 Fiat 500X, 2017–2018 Lexus ES, 2011–2015 Kia Optima, 2010–2012 Lexus HS.