225/45R18 vs 225/50R17
225/50R17 is 3.0 mm shorter than 225/45R18 in overall diameter (−0.5%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 225/50R17 fitted, the speedometer reads 100 km/h when you are doing 99.5 km/h.
Dimensions side by side
| 225/45R18 | 225/50R17 | |
|---|---|---|
| Overall diameter | 660 mm (26.0″) | 657 mm (25.9″) |
| Section width | 225 mm | 225 mm |
| Sidewall height | 101 mm | 113 mm |
| Rim | 18″ | 17″ |
| Revolutions per km | 482 | 484 |
| In stock | 95 tires from $112.00 | 51 tires from $111.00 |
What changes
- Overall diameter: 225/50R17 is 3.0 mm shorter (−0.5%).
- Speedometer: reads 100 km/h at an actual 99.5 km/h with 225/50R17.
- Wheel size changes from 18″ to 17″: 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 225/45R18
Vehicles that use 225/50R17
See every alternate size for 225/45R18
Frequently asked questions
Can I use 225/50R17 instead of 225/45R18?
Usually, yes: 225/50R17 is within 3% of the overall diameter of 225/45R18 (−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 225/45R18 and 225/50R17?
With 225/50R17 instead of 225/45R18, the speedometer shows 100 km/h when you are actually doing 99.5 km/h.
Which vehicles came with both 225/45R18 and 225/50R17?
Both sizes were original equipment, on different trims or packages, on the 2017–2024 Alfa Romeo Giulia, 2015–2021 Mercedes-Benz C300, 2017–2019 BMW 330i, 2019 Jaguar XE, 2016–2018 BMW 328d, 2017–2018 BMW 430i.