265/35R21 vs 305/30R21
305/30R21 is 3.0 mm shorter than 265/35R21 in overall diameter (−0.4%), within the usual 3% limit, so it can replace it where the wheels and clearance allow. With 305/30R21 fitted, the speedometer reads 100 km/h when you are doing 99.6 km/h.
Dimensions side by side
| 265/35R21 | 305/30R21 | |
|---|---|---|
| Overall diameter | 719 mm (28.3″) | 716 mm (28.2″) |
| Section width | 265 mm | 305 mm |
| Sidewall height | 93 mm | 92 mm |
| Rim | 21″ | 21″ |
| Revolutions per km | 443 | 445 |
| In stock | 12 tires from $372.00 | 5 tires from $382.00 |
What changes
- Overall diameter: 305/30R21 is 3.0 mm shorter (−0.4%).
- Speedometer: reads 100 km/h at an actual 99.6 km/h with 305/30R21.
- 305/30R21 is 40 mm wider, so check clearance and the recommended rim width.
- Choose a load index at least as high as the one on your door placard.
Vehicles that came with both sizes
Vehicles that use 265/35R21
Vehicles that use 305/30R21
See every alternate size for 265/35R21
Frequently asked questions
Can I use 305/30R21 instead of 265/35R21?
Usually, yes: 305/30R21 is within 3% of the overall diameter of 265/35R21 (−0.4%). 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 265/35R21 and 305/30R21?
With 305/30R21 instead of 265/35R21, the speedometer shows 100 km/h when you are actually doing 99.6 km/h.
Which vehicles came with both 265/35R21 and 305/30R21?
Both sizes were original equipment, on different trims or packages, on the 2020–2024 Porsche Taycan, 2022–2024 Audi e-tron, 2019–2023 Aston Martin DBS.