245/35R19 vs 245/40R18
245/40R18 is 1.0 mm shorter than 245/35R19 in overall diameter (−0.2%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 245/40R18 fitted, the speedometer reads 100 km/h when you are doing 99.8 km/h.
Dimensions side by side
| 245/35R19 | 245/40R18 | |
|---|---|---|
| Overall diameter | 654 mm (25.7″) | 653 mm (25.7″) |
| Section width | 245 mm | 245 mm |
| Sidewall height | 86 mm | 98 mm |
| Rim | 19″ | 18″ |
| Revolutions per km | 487 | 487 |
| In stock | 23 tires from $229.00 | 62 tires from $119.00 |
What changes
- Overall diameter: 245/40R18 is 1.0 mm shorter (−0.2%).
- Speedometer: reads 100 km/h at an actual 99.8 km/h with 245/40R18.
- 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 245/35R19
Vehicles that use 245/40R18
See every alternate size for 245/35R19
Frequently asked questions
Can I use 245/40R18 instead of 245/35R19?
Usually, yes: 245/40R18 is within 3% of the overall diameter of 245/35R19 (−0.2%). 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 245/35R19 and 245/40R18?
With 245/40R18 instead of 245/35R19, the speedometer shows 100 km/h when you are actually doing 99.8 km/h.
Which vehicles came with both 245/35R19 and 245/40R18?
Both sizes were original equipment, on different trims or packages, on the 2016–2024 Audi A4, 2016–2023 Audi TT, 2016–2021 Mercedes-Benz C63, 2018–2019 Audi S4, 2015–2016 Mercedes-Benz E250, 2016 Mercedes-Benz E350.