195/65R15 vs 265/70R15
New overall diameter
29.61″
was 24.98″
True speed at an indicated 60
71.1 mph
your speedo reads low
Revolutions per mile
681
was 807, −126
| Measurement | 195/65R15 | 265/70R15 | Change |
|---|---|---|---|
| Overall diameter | 24.98″ | 29.61″ | +4.63″ (+18.5%) |
| Sidewall height | 4.99″ (126.8 mm) | 7.30″ (185.5 mm) | +58.8 mm |
| Tread width | 195 mm | 265 mm | +70 mm |
| Circumference | 78.48″ | 93.01″ | +14.53″ |
| Revs per mile | 807 | 681 | −126 |
| Speedometer error | baseline | +18.5% | reads low |
Diameter overlay
195/65R15 265/70R15
Speedometer check
With 265/70R15 fitted, when the speedometer shows the indicated speed, your actual speed is:
25 mph shown
29.6 mph actual
35 mph shown
41.5 mph actual
45 mph shown
53.3 mph actual
55 mph shown
65.2 mph actual
65 mph shown
77.0 mph actual
75 mph shown
88.9 mph actual
Common questions
- Will 265/70R15 fit instead of 195/65R15?
- Overall diameter changes 18.5%; section width changes 70 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 24.98″ to 29.61″, a change of +18.5%. 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 265/70R15?
- At an indicated 60 mph you are really doing about 71.1 mph, a +18.5% error. The speedometer reads low, so you are going faster than it shows.
- What is the difference in revolutions per mile between 195/65R15 and 265/70R15?
- 195/65R15 turns about 807 times per mile and 265/70R15 turns about 681, a difference of −126. Your speedometer and odometer both count rotations, so this number is what throws them off.