235/60R16 vs 225/70R16
New overall diameter
28.40″
was 27.10″
True speed at an indicated 60
62.9 mph
your speedo reads low
Revolutions per mile
710
was 744, −34
| Measurement | 235/60R16 | 225/70R16 | Change |
|---|---|---|---|
| Overall diameter | 27.10″ | 28.40″ | +1.30″ (+4.8%) |
| Sidewall height | 5.55″ (141.0 mm) | 6.20″ (157.5 mm) | +16.5 mm |
| Tread width | 235 mm | 225 mm | −10 mm |
| Circumference | 85.14″ | 89.23″ | +4.08″ |
| Revs per mile | 744 | 710 | −34 |
| Speedometer error | baseline | +4.8% | reads low |
Diameter overlay
235/60R16 225/70R16
Speedometer check
With 225/70R16 fitted, when the speedometer shows the indicated speed, your actual speed is:
25 mph shown
26.2 mph actual
35 mph shown
36.7 mph actual
45 mph shown
47.2 mph actual
55 mph shown
57.6 mph actual
65 mph shown
68.1 mph actual
75 mph shown
78.6 mph actual
Common questions
- Will 225/70R16 fit instead of 235/60R16?
- At 4.8% this lands between the 3% and 5% marks. Plenty of people run swaps like this, but you will see real speedometer error, and you want to check the wheel well at full lock and full compression before you buy. Your speedometer will read low, so you are going faster than it says. Overall diameter goes from 27.10″ to 28.40″, a change of +4.8%. 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 225/70R16?
- At an indicated 60 mph you are really doing about 62.9 mph, a +4.8% error. The speedometer reads low, so you are going faster than it shows.
- What is the difference in revolutions per mile between 235/60R16 and 225/70R16?
- 235/60R16 turns about 744 times per mile and 225/70R16 turns about 710, a difference of −34. Your speedometer and odometer both count rotations, so this number is what throws them off.