TireSize

335/30R20 Tire Size

335/30R20 diameter, sidewall, revolutions per mile, and plus-sizing options.

The 335/30R20 tire size breaks down as: 335 mm section width, 30% aspect ratio, and a 20-inch rim. Below are its real, calculated dimensions.

335/30R20 Calculated Dimensions

MetricValue
Overall diameter27.9 in (709 mm)
Sidewall height4.0 in (101 mm)
Circumference87.7 in (2227 mm)
Revolutions per mile723

Typical Fitment

335/30R20 is most often found on exotic performance cars. Always confirm against the door-jamb placard or owner manual before fitting.

Plus-Sizing Alternatives

These sizes keep the overall diameter close to 335/30R20, so speedometer and gearing stay near stock:

SizeDiameterDiameter change
345/30R2028.15 in+0.8%
345/25R2127.79 in-0.4%
355/20R2227.59 in-1.2%

Speedometer Note

If you fit a 345/30R20 instead of 335/30R20, the diameter changes by +0.8%. A taller tire makes your speedometer read low — at a true 60 mph it would show roughly 59 mph. A shorter tire has the opposite effect, so the gauge reads high.

Use the tire calculator to compare 335/30R20 against any other size and see the exact diameter and speedometer difference.

By Daniel Reyes, automotive editor

Frequently Asked Questions

What does 335/30R20 mean?

335/30R20 means a 335 mm wide tire with a 30% sidewall aspect ratio mounted on a 20-inch rim. The aspect ratio is the sidewall height as a percentage of the width.

Can I plus-size from 335/30R20?

Yes, as long as the replacement keeps the overall diameter close to stock so the speedometer stays accurate. Common plus-size moves from 335/30R20 are 345/30R20, 345/25R21, 355/20R22.

Will 335/30R20 affect my speedometer?

Only if it differs in diameter from your original size. A taller tire reads low; a shorter tire reads high. Compare the two sizes with the calculator to find the percentage.

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