205/60R16 vs 245/45R17
New overall diameter
25.68″
was 25.69″
True speed at an indicated 60
60.0 mph
no meaningful change
Revolutions per mile
785
was 785, +0
| Measurement | 205/60R16 | 245/45R17 | Change |
|---|---|---|---|
| Overall diameter | 25.69″ | 25.68″ | −0.00″ (−0.0%) |
| Sidewall height | 4.84″ (123.0 mm) | 4.34″ (110.3 mm) | −12.8 mm |
| Tread width | 205 mm | 245 mm | +40 mm |
| Circumference | 80.69″ | 80.68″ | −0.01″ |
| Revs per mile | 785 | 785 | +0 |
| Speedometer error | baseline | −0.0% | no change |
Diameter overlay
205/60R16 245/45R17
Speedometer check
With 245/45R17 fitted, when the speedometer shows the indicated speed, your actual speed is:
25 mph shown
25.0 mph actual
35 mph shown
35.0 mph actual
45 mph shown
45.0 mph actual
55 mph shown
55.0 mph actual
65 mph shown
65.0 mph actual
75 mph shown
75.0 mph actual
Common questions
- Will 245/45R17 fit instead of 205/60R16?
- Diameter moves 0.0%, comfortably inside the 3% rule. Your speedometer, ABS, traction control and gearing all stay in the range they were calibrated for. Your speedometer stays accurate. Overall diameter goes from 25.69″ to 25.68″, a change of −0.0%. The rule of thumb most shops use: under 3% is fine, 3 to 5% needs a clearance check, over 5% needs recalibration.
- How far off will my speedometer read on 245/45R17?
- At an indicated 60 mph you are really doing about 60.0 mph, a −0.0% error. That is effectively no change.
- What is the difference in revolutions per mile between 205/60R16 and 245/45R17?
- 205/60R16 turns about 785 times per mile and 245/45R17 turns about 785, a difference of +0. Your speedometer and odometer both count rotations, so this number is what throws them off.