305/30 R21 Tires
Everything we know about the 305/30 R21 tire size: 7 owner reviews covering 31,800 miles of driving, and EU label data for the tires you can actually buy in it.
- 7owner reviews
- 31,800 milescovered on them
- 50tires made in this size
305/30 R21 EU tire label data
EU label values are declared for each individual size, so the figures here are exact for 305/30 R21 rather than a range across a model. 40 tires carry label data in this size. The most common load index is 104 (up to 900 kg per tire). Speed ratings on offer: (Y) (301 km/h), Y (300 km/h), W (270 km/h), V (240 km/h), H (210 km/h), T (190 km/h). 11 tires in this size carry the 3PMSF severe snow marking.
A Best wet grip
23 tires in this size hold the top EU wet grip rating, class A. The highest scoring on Tire Reviews:
- Pirelli P Zero Winter 2 Winter 9.8
- Continental SportContact 7 Summer 9.7
- Hankook Ventus Evo Summer 9.4
- Kumho Ecsta Sport S PS72 Summer 9.3
- Bridgestone Potenza Sport Summer 9.3
- Hankook iON Evo Summer 9.3
A Lowest rolling resistance
The most fuel efficient choice: 4 tires in this size reach rolling resistance class A. The highest scoring on Tire Reviews:
- Hankook iON Evo Summer 9.3
- Bridgestone Potenza Sport Summer 9.3
- Pirelli P Zero Summer 8.8
- Hankook Ventus iON S Summer
69dB Quietest tires
The quietest 305/30 R21 tires are labelled at 69 dB external noise:
- Hankook iON Evo Summer 9.3
- Pirelli P Zero Summer 8.8
- Hankook Ventus iON S Summer
Label values come from the EU EPREL database and apply to the EU market versions of each tire. Wet grip and rolling resistance run from class A (best) to E; noise is the measured drive-by figure. A good label is a floor, not a verdict - the tests and owner ratings above tell you far more.
What does 305/30 R21 mean?
A 305/30 R21 tire is 305 mm wide, its sidewall is 30% of that width (92 mm) tall, and it fits a 21 inch wheel. That gives an overall diameter of roughly 716 mm.
| Section width | 305 mm |
|---|---|
| Sidewall height | 92 mm |
| Rim diameter | 21" (533 mm) |
| Overall diameter | ≈ 716 mm |
| Circumference | ≈ 2,251 mm |
| Revolutions per km | ≈ 444 |
| Revolutions per mile | ≈ 715 |
Also written as
305/30R21 305/30 ZR21 305-30-21 305 30 21
Figures are calculated from the nominal size. A loaded, rolling tire runs a few percent smaller, and true widths vary slightly between makes.
What cars use 305/30 R21 tires?
The cars most often running this size in our owner reviews. Each links to the best rated tires for that exact car.
Every tire reviewed in 305/30 R21
The complete record, including discontinued tires and tires with too few reviews to rank, ordered by the amount of evidence. A further 5 tires have a single review each; they count toward the totals but are not listed.
| Tire | Season | Owner rating | Reviews | Distance reviewed |
|---|---|---|---|---|
| Continental SportContact 7 | Summer | 94% | 2 | 5,200 miles |
Reviews only cover part of the market: 50 tires are made in 305/30 R21. Browse every 305/30 R21 tire →
What drivers say about their 305/30 R21 tires
The most recent owner reviews fitted in this size, in their own words.
Drive on 305/30 R21 tires?
Review your tires and help the next driver choose. It takes about five minutes, and every review on this page came from a driver who took them.
Where this data comes from
Owner ratings are submitted through the review form on this site, naming the tire, the size and the distance covered, and are checked by hand before publication. Test results come from independent published tire tests indexed by size, and label values from the EU EPREL database.
About the TR Score
The Tire Reviews Score rates each tire out of 10 using independent test results and the full body of owner reviews, so you can check a car-specific ranking against the wider evidence.
Who does the testing
Every test published as a Tire Reviews test is run by Jonathan Benson, who has been testing tires independently since 2007.

