245/40R18 vs 255/35R19
255/35R19 is 8.0 mm taller than 245/40R18 in overall diameter (+1.2%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 255/35R19 fitted, the speedometer reads 100 km/h when you are doing 101.2 km/h.
Dimensions side by side
| 245/40R18 | 255/35R19 | |
|---|---|---|
| Overall diameter | 653 mm (25.7″) | 661 mm (26.0″) |
| Section width | 245 mm | 255 mm |
| Sidewall height | 98 mm | 89 mm |
| Rim | 18″ | 19″ |
| Revolutions per km | 487 | 482 |
| In stock | 62 tires from $119.00 | 55 tires from $151.00 |
What changes
- Overall diameter: 255/35R19 is 8.0 mm taller (+1.2%).
- Speedometer: reads 100 km/h at an actual 101.2 km/h with 255/35R19.
- 255/35R19 is 10 mm wider, so check clearance and the recommended rim width.
- Wheel size changes from 18″ to 19″: 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 245/40R18
Vehicles that use 255/35R19
See every alternate size for 245/40R18
Frequently asked questions
Can I use 255/35R19 instead of 245/40R18?
Usually, yes: 255/35R19 is within 3% of the overall diameter of 245/40R18 (+1.2%). 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 245/40R18 and 255/35R19?
With 255/35R19 instead of 245/40R18, the speedometer shows 100 km/h when you are actually doing 101.2 km/h.
Which vehicles came with both 245/40R18 and 255/35R19?
Both sizes were original equipment, on different trims or packages, on the 2010–2024 Audi A5, 2015–2024 Mercedes-Benz C300, 2009–2016, 2020–2024 Audi S4, 2017–2023 Mercedes-Benz C43, 2020–2023 Mercedes-Benz CLA45, 2013–2021 Audi S5.