The 215/45R18 is a common tire size for midsize sedans such as Toyota Camry, Honda Accord, and Hyundai Sonata.
With a 96.8 mm sidewall (45% aspect ratio), this tire offers a balanced blend of ride comfort and handling precision — versatile for both city driving and spirited cornering.
Compared to the baseline 235/45R18, this tire's overall diameter differs by -2.7% — a speedometer calibrated for 235/45R18 would read 102.8 km/h at an actual 100 km/h.
Fitted to the Mazda Mazda3 (BP, 2019+) and Audi A3 (8V) Sportback S-Line. Load index 89W or 93Y reinforced. Wheel width 7.0-8.0"; pairing with 7.5" rims is the typical OE setup.
Mainstream sedan sizes balance compound longevity against light all-season handling. When replacing, match the OE speed rating (H or V on most trims) — installing a lower rating voids many manufacturer load-test certifications and is illegal on autobahn-rated vehicles. Wheel-well clearance is rarely a concern at this rim diameter; speedometer drift across factory alternatives stays well inside the ±3% legal window.
| Tire Code | 215/45R18 |
| Section Width | 215 mm |
| Aspect Ratio | 45% |
| Rim Diameter | 18" |
| Sidewall Height | 96.8 mm |
| Overall Diameter | 650.7 mm / 25.62" |
| Circumference | 2044.2 mm / 80.48" |
| Revolutions per km | 489.2 |
| Revolutions per mile | 787.3 |
| Tire Code | OD (mm) | Δ mm | Δ % | Speedo at 100 km/h |
|---|---|---|---|---|
| 215/45R17 | 625.3 | -25.4 | -3.9% | 104.1 |
| 215/40R18 | 629.2 | -21.5 | -3.3% | 103.4 |
| 215/45R18 (current) | 650.7 | — | — | 100.0 |
| 225/45R18 | 659.7 | +9.0 | +1.4% | 98.6 |
| 235/45R18 | 668.7 | +18.0 | +2.8% | 97.3 |