The 245/45R18 is a common tire size for midsize sedans such as Toyota Camry, Honda Accord, and Hyundai Sonata.
With a 110.3 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 +1.3% — a speedometer calibrated for 235/45R18 would read 98.7 km/h at an actual 100 km/h.
OE on the Audi A6 (C7 18" packages) and BMW 7 Series (F01/F02 base). Load index 96W or 100Y reinforced. Full-size luxury-sedan size; ride-quality oriented compounds (Michelin Primacy, Pirelli P7) dominate the replacement market.
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 | 245/45R18 |
| Section Width | 245 mm |
| Aspect Ratio | 45% |
| Rim Diameter | 18" |
| Sidewall Height | 110.3 mm |
| Overall Diameter | 677.7 mm / 26.68" |
| Circumference | 2129.1 mm / 83.82" |
| Revolutions per km | 469.7 |
| Revolutions per mile | 755.9 |
| Tire Code | OD (mm) | Δ mm | Δ % | Speedo at 100 km/h |
|---|---|---|---|---|
| 245/45R17 | 652.3 | -25.4 | -3.7% | 103.9 |
| 245/40R18 | 653.2 | -24.5 | -3.6% | 103.8 |
| 235/45R18 | 668.7 | -9.0 | -1.3% | 101.3 |
| 245/45R18 (current) | 677.7 | — | — | 100.0 |
| 255/45R18 | 686.7 | +9.0 | +1.3% | 98.7 |
| 245/45R19 | 703.1 | +25.4 | +3.7% | 96.4 |