225/65R16 vs 235/70R16
New overall diameter
28.95″
was 27.52″
True speed at an indicated 60
63.1 mph
your speedo reads low
Revolutions per mile
697
was 733, −36
| Measurement | 225/65R16 | 235/70R16 | Change |
|---|---|---|---|
| Overall diameter | 27.52″ | 28.95″ | +1.44″ (+5.2%) |
| Sidewall height | 5.76″ (146.3 mm) | 6.48″ (164.5 mm) | +18.3 mm |
| Tread width | 225 mm | 235 mm | +10 mm |
| Circumference | 86.44″ | 90.96″ | +4.51″ |
| Revs per mile | 733 | 697 | −36 |
| Speedometer error | baseline | +5.2% | reads low |
Diameter overlay
225/65R16 235/70R16
Speedometer check
With 235/70R16 fitted, when the speedometer shows the indicated speed, your actual speed is:
25 mph shown
26.3 mph actual
35 mph shown
36.8 mph actual
45 mph shown
47.4 mph actual
55 mph shown
57.9 mph actual
65 mph shown
68.4 mph actual
75 mph shown
78.9 mph actual
Common questions
- Will 235/70R16 fit instead of 225/65R16?
- 5.2% is past the 5% mark, which is where this stops being a tire choice and starts being a project. Expect rubbing, meaningful speedometer error, and extra load on ABS, stability control and the drivetrain. Recalibration is the usual fix. Your speedometer will read low, so you are going faster than it says. Overall diameter goes from 27.52″ to 28.95″, a change of +5.2%. 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 235/70R16?
- At an indicated 60 mph you are really doing about 63.1 mph, a +5.2% error. The speedometer reads low, so you are going faster than it shows.
- What is the difference in revolutions per mile between 225/65R16 and 235/70R16?
- 225/65R16 turns about 733 times per mile and 235/70R16 turns about 697, a difference of −36. Your speedometer and odometer both count rotations, so this number is what throws them off.