225/40R18 vs 245/35R18
245/35R18 is 8.0 mm shorter than 225/40R18 in overall diameter (−1.3%), 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 98.7 km/h.
Dimensions side by side
| 225/40R18 | 245/35R18 | |
|---|---|---|
| Overall diameter | 637 mm (25.1″) | 629 mm (24.8″) |
| Section width | 225 mm | 245 mm |
| Sidewall height | 90 mm | 86 mm |
| Rim | 18″ | 18″ |
| Revolutions per km | 500 | 506 |
| In stock | 77 tires from $110.00 | 6 tires from $200.00 |
What changes
- Overall diameter: 245/35R18 is 8.0 mm shorter (−1.3%).
- Speedometer: reads 100 km/h at an actual 98.7 km/h with 245/35R18.
- 245/35R18 is 20 mm wider, so check clearance and the recommended rim width.
- Choose a load index at least as high as the one on your door placard.
Vehicles that came with both sizes
Vehicles that use 225/40R18
Vehicles that use 245/35R18
See every alternate size for 225/40R18
Frequently asked questions
Can I use 245/35R18 instead of 225/40R18?
Usually, yes: 245/35R18 is within 3% of the overall diameter of 225/40R18 (−1.3%). 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 225/40R18 and 245/35R18?
With 245/35R18 instead of 225/40R18, the speedometer shows 100 km/h when you are actually doing 98.7 km/h.
Which vehicles came with both 225/40R18 and 245/35R18?
Both sizes were original equipment, on different trims or packages, on the 2017–2021 BMW 230i, 2017–2021 BMW M240i, 2017–2020 Mercedes-Benz SLC300, 2014–2016 BMW 228i, 2009–2016 Mercedes-Benz SLK350, 2014–2016 BMW M235i.