225/50R18 vs 245/45R18
245/45R18 is 4.0 mm shorter than 225/50R18 in overall diameter (−0.6%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 245/45R18 fitted, the speedometer reads 100 km/h when you are doing 99.4 km/h.
Dimensions side by side
| 225/50R18 | 245/45R18 | |
|---|---|---|
| Overall diameter | 682 mm (26.9″) | 678 mm (26.7″) |
| Section width | 225 mm | 245 mm |
| Sidewall height | 113 mm | 110 mm |
| Rim | 18″ | 18″ |
| Revolutions per km | 467 | 469 |
| In stock | 59 tires from $132.00 | 50 tires from $118.00 |
What changes
- Overall diameter: 245/45R18 is 4.0 mm shorter (−0.6%).
- Speedometer: reads 100 km/h at an actual 99.4 km/h with 245/45R18.
- 245/45R18 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 225/50R18
Vehicles that use 245/45R18
See every alternate size for 225/50R18
Frequently asked questions
Can I use 245/45R18 instead of 225/50R18?
Usually, yes: 245/45R18 is within 3% of the overall diameter of 225/50R18 (−0.6%). 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 225/50R18 and 245/45R18?
With 245/45R18 instead of 225/50R18, the speedometer shows 100 km/h when you are actually doing 99.4 km/h.
Which vehicles came with both 225/50R18 and 245/45R18?
Both sizes were original equipment, on different trims or packages, on the 2009–2020 Nissan 370Z, 2014–2015 Infiniti Q60, 2009–2013 Infiniti G37, 2007–2008 Infiniti G35.