The 245/45R20 is a common tire size for luxury and premium vehicles such as BMW 5 Series, Mercedes-Benz E-Class, and Audi A6.
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 265/50R20, this tire's overall diameter differs by -5.8% — a speedometer calibrated for 265/50R20 would read 106.1 km/h at an actual 100 km/h.
OE on the Audi e-tron GT, BMW X4 (G02) M40i and Acura RDX. Load index 103W or 107Y reinforced. Premium EV / luxury SUV-coupe size; high-load (XL/RF) options are commonly required.
Large-rim luxury-SUV sizes prioritize acoustic refinement and curb-weight load capacity over off-road versatility. Self-sealing and runflat constructions are common OE on these fitments; replacing a runflat with a conventional tire requires confirming the TPMS module and spare-tire provisioning since most platforms ship without a spare. Air-suspension calibration is also tied to rolling diameter — staying within ±1% of OE is recommended on Range Rover and BMW X5/X7 platforms.
| Tire Code | 245/45R20 |
| Section Width | 245 mm |
| Aspect Ratio | 45% |
| Rim Diameter | 20" |
| Sidewall Height | 110.3 mm |
| Overall Diameter | 728.5 mm / 28.68" |
| Circumference | 2288.7 mm / 90.10" |
| Revolutions per km | 436.9 |
| Revolutions per mile | 703.2 |
| Tire Code | OD (mm) | Δ mm | Δ % | Speedo at 100 km/h |
|---|---|---|---|---|
| 245/45R18 | 677.7 | -50.8 | -7.0% | 107.5 |
| 245/45R19 | 703.1 | -25.4 | -3.5% | 103.6 |
| 245/45R20 (current) | 728.5 | — | — | 100.0 |
| 255/45R20 | 737.5 | +9.0 | +1.2% | 98.8 |
| 265/45R20 | 746.5 | +18.0 | +2.5% | 97.6 |