225/65R17 vs 235/55R18
235/55R18 is 8.0 mm shorter than 225/65R17 in overall diameter (−1.1%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 235/55R18 fitted, the speedometer reads 100 km/h when you are doing 98.9 km/h.
Dimensions side by side
| 225/65R17 | 235/55R18 | |
|---|---|---|
| Overall diameter | 724 mm (28.5″) | 716 mm (28.2″) |
| Section width | 225 mm | 235 mm |
| Sidewall height | 146 mm | 129 mm |
| Rim | 17″ | 18″ |
| Revolutions per km | 440 | 445 |
| In stock | 84 tires from $115.00 | 60 tires from $128.00 |
What changes
- Overall diameter: 235/55R18 is 8.0 mm shorter (−1.1%).
- Speedometer: reads 100 km/h at an actual 98.9 km/h with 235/55R18.
- 235/55R18 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 225/65R17
Vehicles that use 235/55R18
See every alternate size for 225/65R17
Frequently asked questions
Can I use 235/55R18 instead of 225/65R17?
Usually, yes: 235/55R18 is within 3% of the overall diameter of 225/65R17 (−1.1%). 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 225/65R17 and 235/55R18?
With 235/55R18 instead of 225/65R17, the speedometer shows 100 km/h when you are actually doing 98.9 km/h.
Which vehicles came with both 225/65R17 and 235/55R18?
Both sizes were original equipment, on different trims or packages, on the 2010–2017 Chevrolet Equinox, 2010–2011 GMC Terrain, 2004–2009 Lexus RX.