Tyre size
Best 305/30 R21 tyres
Picked for the 3 fitments that run 305/30 R21 from the factory, ranked by independent test results and set for the most demanding of them, so every pick suits every car here.
- width
- 305 mm
- sidewall
- 92 mm
- diameter
- 716 mm
- rim
- 21 in
- factory ratings
- 100Y, 104Y
Best tyres in 305/30 R21
Best overall
Bridgestone
Potenza Sport
Highest fit score for everyday driving on the cars that use this size.
Max performance summer · Premium · fit 74
Best in the wet
Continental
SportContact 7
Strongest wet braking and handling in independent tests.
Max performance summer · Premium · fit 72
Best performance
Michelin
Pilot Sport 4S
Most dry grip and steering response for spirited roads.
Max performance summer · Premium · fit 77
Best value
Kumho
Ecsta PS91
The highest-scoring lower-priced tyre in the same category.
Max performance summer · Value · fit 49
Best road + track
Continental
ExtremeContact Force
A 200-treadwear tyre for track days that still drives home.
Extreme performance (200TW) · Mid-range · fit 70
Not every tyre is made in every size. “See today’s price” opens the tyre in 305/30 R21 when the retailer stocks it, or the tyre’s page when it doesn’t. Match or beat the load index and speed rating on your placard.
Cars on 305/30 R21 from the factory
| Car | Fitment | Category it needs |
|---|---|---|
| Porsche 911 Carrera (992.2) | 305/30 ZR21 100Y rear · Standard 20/21-inch | Ultra-high performance summer |
| Porsche 911 Carrera S (992) | 305/30 ZR21 104Y XL rear · Standard 20/21-inch | Max performance summer |
| Porsche Taycan Turbo S (2024, overboost) | 305/30 R21 rear · 21-inch option | Max performance summer |
The picks above are max performance summer tyres or better. A car that needs a gentler category can go lower: its own page shows how far.
305/30 R21 questions
What are the best 305/30 R21 tyres?
For the cars that use 305/30 R21 from the factory, ratio's top pick is the Bridgestone Potenza Sport, a max performance summer tyre. Best in the wet: Continental SportContact 7. Best performance: Michelin Pilot Sport 4S. Best value: Kumho Ecsta PS91. Best road + track: Continental ExtremeContact Force.
Which cars use 305/30 R21 tyres?
Porsche 911 Carrera (992.2) (rear), Porsche 911 Carrera S (992) (rear), Porsche Taycan Turbo S (2024, overboost) (rear). Always check the placard on your own car: wheels and tyres get changed.
How big is a 305/30 R21 tyre?
About 716 mm (28.2 in) tall overall, 305 mm wide, with a 92 mm sidewall, on an 21-inch rim.