245/40R20 vs 245/45R19
245/45R19 is 1.0 mm shorter than 245/40R20 in overall diameter (−0.1%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 245/45R19 fitted, the speedometer reads 100 km/h when you are doing 99.9 km/h.
Dimensions side by side
| 245/40R20 | 245/45R19 | |
|---|---|---|
| Overall diameter | 704 mm (27.7″) | 703 mm (27.7″) |
| Section width | 245 mm | 245 mm |
| Sidewall height | 98 mm | 110 mm |
| Rim | 20″ | 19″ |
| Revolutions per km | 452 | 453 |
| In stock | 34 tires from $238.00 | 64 tires from $152.00 |
What changes
- Overall diameter: 245/45R19 is 1.0 mm shorter (−0.1%).
- Speedometer: reads 100 km/h at an actual 99.9 km/h with 245/45R19.
- Wheel size changes from 20″ 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 245/40R20
Vehicles that use 245/45R19
See every alternate size for 245/40R20
Frequently asked questions
Can I use 245/45R19 instead of 245/40R20?
Usually, yes: 245/45R19 is within 3% of the overall diameter of 245/40R20 (−0.1%). 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 245/40R20 and 245/45R19?
With 245/45R19 instead of 245/40R20, the speedometer shows 100 km/h when you are actually doing 99.9 km/h.
Which vehicles came with both 245/40R20 and 245/45R19?
Both sizes were original equipment, on different trims or packages, on the 2022–2024 Lucid Air, 2023–2024 BMW X1, 2024 BMW 530i, 2024 BMW i5, 2021–2024 Mercedes-Benz E450, 2021–2024 Polestar Polestar 2.