225/45R17 vs 245/35R18
245/35R18 is 5.0 mm shorter than 225/45R17 in overall diameter (−0.8%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 245/35R18 fitted, the speedometer reads 100 km/h when you are doing 99.2 km/h.
Dimensions side by side
| 225/45R17 | 245/35R18 | |
|---|---|---|
| Overall diameter | 634 mm (25.0″) | 629 mm (24.8″) |
| Section width | 225 mm | 245 mm |
| Sidewall height | 101 mm | 86 mm |
| Rim | 17″ | 18″ |
| Revolutions per km | 502 | 506 |
| In stock | 59 tires from $101.00 | 6 tires from $200.00 |
What changes
- Overall diameter: 245/35R18 is 5.0 mm shorter (−0.8%).
- Speedometer: reads 100 km/h at an actual 99.2 km/h with 245/35R18.
- 245/35R18 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 225/45R17
Vehicles that use 245/35R18
See every alternate size for 225/45R17
Frequently asked questions
Can I use 245/35R18 instead of 225/45R17?
Usually, yes: 245/35R18 is within 3% of the overall diameter of 225/45R17 (−0.8%). 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 225/45R17 and 245/35R18?
With 245/35R18 instead of 225/45R17, the speedometer shows 100 km/h when you are actually doing 99.2 km/h.
Which vehicles came with both 225/45R17 and 245/35R18?
Both sizes were original equipment, on different trims or packages, on the 2017–2020 Mercedes-Benz SLC300, 2012–2016 Mercedes-Benz SLK350, 2011–2013 BMW 135i.