245/50R18 vs 275/35R20
275/35R20 is 1.0 mm shorter than 245/50R18 in overall diameter (−0.1%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 275/35R20 fitted, the speedometer reads 100 km/h when you are doing 99.9 km/h.
Dimensions side by side
| 245/50R18 | 275/35R20 | |
|---|---|---|
| Overall diameter | 702 mm (27.6″) | 701 mm (27.6″) |
| Section width | 245 mm | 275 mm |
| Sidewall height | 123 mm | 96 mm |
| Rim | 18″ | 20″ |
| Revolutions per km | 453 | 454 |
| In stock | 14 tires from $129.00 | 19 tires from $191.00 |
What changes
- Overall diameter: 275/35R20 is 1.0 mm shorter (−0.1%).
- Speedometer: reads 100 km/h at an actual 99.9 km/h with 275/35R20.
- 275/35R20 is 30 mm wider, so check clearance and the recommended rim width.
- Wheel size changes from 18″ to 20″: 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 245/50R18
Vehicles that use 275/35R20
See every alternate size for 245/50R18
Frequently asked questions
Can I use 275/35R20 instead of 245/50R18?
Usually, yes: 275/35R20 is within 3% of the overall diameter of 245/50R18 (−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 245/50R18 and 275/35R20?
With 275/35R20 instead of 245/50R18, the speedometer shows 100 km/h when you are actually doing 99.9 km/h.
Which vehicles came with both 245/50R18 and 275/35R20?
Both sizes were original equipment, on different trims or packages, on the 2018–2020 Mercedes-Benz S450, 2018–2020 Mercedes-Benz S560, 2015–2017 Mercedes-Benz S550, 2016–2017 Mercedes-Benz S550e, 2011–2016 BMW 740i, 2006–2015 BMW 750i.