265/70R16 vs 225/75R16
New overall diameter
29.29″
was 30.61″
True speed at an indicated 60
57.4 mph
your speedo reads high
Revolutions per mile
689
was 659, +30
| Measurement | 265/70R16 | 225/75R16 | Change |
|---|---|---|---|
| Overall diameter | 30.61″ | 29.29″ | −1.32″ (−4.3%) |
| Sidewall height | 7.30″ (185.5 mm) | 6.64″ (168.8 mm) | −16.8 mm |
| Tread width | 265 mm | 225 mm | −40 mm |
| Circumference | 96.15″ | 92.01″ | −4.14″ |
| Revs per mile | 659 | 689 | +30 |
| Speedometer error | baseline | −4.3% | reads high |
Diameter overlay
265/70R16 225/75R16
Speedometer check
With 225/75R16 fitted, when the speedometer shows the indicated speed, your actual speed is:
25 mph shown
23.9 mph actual
35 mph shown
33.5 mph actual
45 mph shown
43.1 mph actual
55 mph shown
52.6 mph actual
65 mph shown
62.2 mph actual
75 mph shown
71.8 mph actual
Common questions
- Will 225/75R16 fit instead of 265/70R16?
- At 4.3% 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 high, so you are going slower than it says. Overall diameter goes from 30.61″ to 29.29″, a change of −4.3%. 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 225/75R16?
- At an indicated 60 mph you are really doing about 57.4 mph, a −4.3% error. The speedometer reads high, so you are going slower than it shows.
- What is the difference in revolutions per mile between 265/70R16 and 225/75R16?
- 265/70R16 turns about 659 times per mile and 225/75R16 turns about 689, a difference of +30. Your speedometer and odometer both count rotations, so this number is what throws them off.