TireSizesFinder

215/65R15 vs 245/45R17

245/45R17 is 0.32 in (8.2 mm) shorter than 215/65R15, a −1.24% diameter difference. With the speedometer set for 215/65R15, an indicated 60 mph is 59.3 mph on 245/45R17.

Is this a safe swap?

Diameter difference −1.24%: within the ±3% guideline

By overall diameter alone, 245/45R17 falls inside the ±3% range commonly used as a guideline when replacing 215/65R15. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 215/65R15 (26.00 in) vs 245/45R17 (25.68 in)215/65R1526.00 in × 8.46 in245/45R1725.68 in × 9.65 in
Side profile and tread width, drawn to the same scale.
215/65R15 vs 245/45R17 differences
Measurement215/65R15245/45R17Difference% diff
Overall diameter26.00 in (660.5 mm)25.68 in (652.3 mm)−0.32 in (−8.2 mm)−1.24%
Sidewall height5.50 in (139.8 mm)4.34 in (110.3 mm)−1.16 in (−29.5 mm)−21.11%
Section width8.46 in (215.0 mm)9.65 in (245.0 mm)+1.18 in (+30.0 mm)+13.95%
Circumference81.69 in (2,075.0 mm)80.68 in (2,049.3 mm)−1.01 in (−25.8 mm)−1.24%
Revolutions per mile776785+10+1.26%
True speed with the speedometer calibrated for 215/65R15
IndicatedActual on 215/65R15Actual on 245/45R17Difference
30 mph30.0 mph29.6 mph−0.4 mph
60 mph60.0 mph59.3 mph−0.7 mph
75 mph75.0 mph74.1 mph−0.9 mph

Ride-height change: 245/45R17 lowers the vehicle by 0.16 in (4.1 mm) at the axle (half the −8.2 mm diameter difference).

245/45R17 is 0.32 in shorter than 215/65R15 and 30 mm wider, a 1.24% difference in overall diameter.

With the speedometer calibrated for 215/65R15, an indicated 60 mph is actually 59.3 mph on 245/45R17, and revolutions per mile change from 776 to 785.

245/45R17 mounts on a 17-inch wheel, a plus-2 fitment from the 15-inch wheel of 215/65R15.

Size pages

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Source: Calculated from standard tire geometry formulas. Verified . How these numbers are calculated.