255/35R19 vs 255/40R18
255/40R18 is 0.0 mm taller than 255/35R19 in overall diameter (±0.0%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 255/40R18 fitted, the speedometer reads 100 km/h when you are doing 100.0 km/h.
Dimensions side by side
| 255/35R19 | 255/40R18 | |
|---|---|---|
| Overall diameter | 661 mm (26.0″) | 661 mm (26.0″) |
| Section width | 255 mm | 255 mm |
| Sidewall height | 89 mm | 102 mm |
| Rim | 19″ | 18″ |
| Revolutions per km | 482 | 482 |
| In stock | 55 tires from $151.00 | 13 tires from $238.00 |
What changes
- Overall diameter: 255/40R18 is 0.0 mm taller (±0.0%).
- Speedometer: reads 100 km/h at an actual 100.0 km/h with 255/40R18.
- Wheel size changes from 19″ 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 255/35R19
Vehicles that use 255/40R18
See every alternate size for 255/35R19
Frequently asked questions
Can I use 255/40R18 instead of 255/35R19?
Usually, yes: 255/40R18 is within 3% of the overall diameter of 255/35R19 (±0.0%). 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 255/35R19 and 255/40R18?
With 255/40R18 instead of 255/35R19, the speedometer shows 100 km/h when you are actually doing 100.0 km/h.
Which vehicles came with both 255/35R19 and 255/40R18?
Both sizes were original equipment, on different trims or packages, on the 2019–2024 BMW Z4, 2020–2024 BMW M340i, 2022–2024 BMW 230i, 2017–2021 Mercedes-Benz C63, 2021 BMW M440i, 2017–2020 BMW 440i.