TireSizesFinder

305/70R16 vs 305/65R17

305/65R17 is 0.20 in (5.1 mm) shorter than 305/70R16, a −0.61% diameter difference. With the speedometer set for 305/70R16, an indicated 60 mph is 59.6 mph on 305/65R17.

Is this a safe swap?

Diameter difference −0.61%: under 1%

By overall diameter alone, 305/65R17 is a near match for 305/70R16; the speedometer changes by less than 1%. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

To-scale drawing: 305/70R16 (32.81 in) vs 305/65R17 (32.61 in)305/70R1632.81 in × 12.01 in305/65R1732.61 in × 12.01 in
Side profile and tread width, drawn to the same scale.
305/70R16 vs 305/65R17 differences
Measurement305/70R16305/65R17Difference% diff
Overall diameter32.81 in (833.4 mm)32.61 in (828.3 mm)−0.20 in (−5.1 mm)−0.61%
Sidewall height8.41 in (213.5 mm)7.81 in (198.3 mm)−0.60 in (−15.2 mm)−7.14%
Section width12.01 in (305.0 mm)12.01 in (305.0 mm)0.00 in (0.0 mm)0.00%
Circumference103.08 in (2,618.2 mm)102.45 in (2,602.2 mm)−0.63 in (−16.0 mm)−0.61%
Revolutions per mile615618+4+0.62%
True speed with the speedometer calibrated for 305/70R16
IndicatedActual on 305/70R16Actual on 305/65R17Difference
30 mph30.0 mph29.8 mph−0.2 mph
60 mph60.0 mph59.6 mph−0.4 mph
75 mph75.0 mph74.5 mph−0.5 mph

Ride-height change: 305/65R17 lowers the vehicle by 0.10 in (2.6 mm) at the axle (half the −5.1 mm diameter difference).

305/65R17 is 0.20 in shorter than 305/70R16 and the same width, a 0.61% difference in overall diameter.

With the speedometer calibrated for 305/70R16, an indicated 60 mph is actually 59.6 mph on 305/65R17, and revolutions per mile change from 615 to 618.

305/65R17 mounts on a 17-inch wheel, a plus-1 fitment from the 16-inch wheel of 305/70R16.

Size pages

Other comparisons with 305/70R16

Other comparisons with 305/65R17

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