225/70R16 vs 215/65R17
New overall diameter
28.00″
was 28.40″
True speed at an indicated 60
59.2 mph
your speedo reads high
Revolutions per mile
720
was 710, +10
| Measurement | 225/70R16 | 215/65R17 | Change |
|---|---|---|---|
| Overall diameter | 28.40″ | 28.00″ | −0.40″ (−1.4%) |
| Sidewall height | 6.20″ (157.5 mm) | 5.50″ (139.8 mm) | −17.8 mm |
| Tread width | 225 mm | 215 mm | −10 mm |
| Circumference | 89.23″ | 87.98″ | −1.25″ |
| Revs per mile | 710 | 720 | +10 |
| Speedometer error | baseline | −1.4% | reads high |
Diameter overlay
225/70R16 215/65R17
Speedometer check
With 215/65R17 fitted, when the speedometer shows the indicated speed, your actual speed is:
25 mph shown
24.6 mph actual
35 mph shown
34.5 mph actual
45 mph shown
44.4 mph actual
55 mph shown
54.2 mph actual
65 mph shown
64.1 mph actual
75 mph shown
73.9 mph actual
Common questions
- Will 215/65R17 fit instead of 225/70R16?
- Overall diameter changes 1.4%; section width changes -10 mm. Diameter comparison alone cannot confirm fitment. Verify the vehicle maker's approved rim width, tire load and speed ratings, and clearance at full steering lock and suspension compression. Confirm any possible ABS, traction-control, speedometer, and drivetrain effects with the vehicle maker or a qualified tire professional. Overall diameter goes from 28.40″ to 28.00″, a change of −1.4%. 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 215/65R17?
- At an indicated 60 mph you are really doing about 59.2 mph, a −1.4% error. The speedometer reads high, so you are going slower than it shows.
- What is the difference in revolutions per mile between 225/70R16 and 215/65R17?
- 225/70R16 turns about 710 times per mile and 215/65R17 turns about 720, a difference of +10. Your speedometer and odometer both count rotations, so this number is what throws them off.