285/40R22 vs 285/45R21
285/45R21 is 3.0 mm taller than 285/40R22 in overall diameter (+0.4%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 285/45R21 fitted, the speedometer reads 100 km/h when you are doing 100.4 km/h.
Dimensions side by side
| 285/40R22 | 285/45R21 | |
|---|---|---|
| Overall diameter | 787 mm (31.0″) | 790 mm (31.1″) |
| Section width | 285 mm | 285 mm |
| Sidewall height | 114 mm | 128 mm |
| Rim | 22″ | 21″ |
| Revolutions per km | 404 | 403 |
| In stock | 18 tires from $399.00 | 23 tires from $400.00 |
What changes
- Overall diameter: 285/45R21 is 3.0 mm taller (+0.4%).
- Speedometer: reads 100 km/h at an actual 100.4 km/h with 285/45R21.
- Wheel size changes from 22″ to 21″: 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 285/40R22
Vehicles that use 285/45R21
See every alternate size for 285/40R22
Frequently asked questions
Can I use 285/45R21 instead of 285/40R22?
Usually, yes: 285/45R21 is within 3% of the overall diameter of 285/40R22 (+0.4%). 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 285/40R22 and 285/45R21?
With 285/45R21 instead of 285/40R22, the speedometer shows 100 km/h when you are actually doing 100.4 km/h.
Which vehicles came with both 285/40R22 and 285/45R21?
Both sizes were original equipment, on different trims or packages, on the 2016–2024 Bentley Bentayga, 2018–2024 Rolls Royce Phantom, 2019–2024 Audi Q8, 2020–2024 Rolls Royce Cullinan, 2020–2024 Audi SQ8, 2019–2024 Lamborghini Urus.