235/70R16 vs 245/60R17
Diameter -1.30% · Speedo at 60 mph reads 59.2 mph actual · Ground clearance -4.8 mm
Generally safe — within the 3% tolerance
The diameter difference is ≤3%, which is the widely-accepted fitment tolerance for speedometer accuracy and ABS/traction-control calibration. Verify clearance and load rating with a tire professional before installing.
Speedometer effect
When the vehicle's speedometer (calibrated to 235/70R16) reads 60 mph, the actual speed with 245/60R17 mounted is:
Speedometer error: -1.30% · Odometer reads low by 1.30%
Full comparison
| Measurement | 235/70R16 | 245/60R17 | Delta |
|---|---|---|---|
| Overall diameter | 28.95" | 28.57" | -1.30% |
| Section width | 235 mm | 245 mm | +10 mm |
| Sidewall height | 164.5 mm | 147 mm | -17.50 mm |
| Rim diameter | 16" | 17" | +1" |
| Circumference | 2310 mm | 2280 mm | -30 mm |
| Revs / mile | 697 | 706 | 9 |
| Ground clearance change | -4.8 mm | ||
Questions about this swap
What is the diameter difference between 235/70R16 and 245/60R17?
245/60R17 is 1.30% smaller in overall diameter than 235/70R16 — a difference of 9.6 mm (0.38 inches).
How does 245/60R17 affect the speedometer if the car was calibrated for 235/70R16?
When the speedometer reads 60 mph (calibrated for 235/70R16), the actual speed with 245/60R17 is 59.2 mph — an error of -1.30%.
Is it safe to replace 235/70R16 with 245/60R17?
Generally safe — within the 3% tolerance. The diameter difference is ≤3%, which is the widely-accepted fitment tolerance for speedometer accuracy and ABS/traction-control calibration. Verify clearance and load rating with a tire professional before installing.
All calculations use standard ETRTO formulas. Confirm fitment with a qualified tire professional and your vehicle's door-placard before purchasing.