32.1" tall, 10.0" wide, 7.5" sidewall
A 255/75R17 tire is 32.1 inches (814 mm) tall and 10.0 inches wide. The sidewall is 75% of the width, 7.5 inches, on a 17-inch wheel, and the tire turns about 629 times per mile.
In flotation terms that is about 32.1x10.0R17. People often call it a 32-inch tire.
The size most often compared with it is 255/70R17, which is 1.0" shorter (−3.1%). At an indicated 60 mph you would be doing 58.1 mph on it, more than the 3% change many shops use as a limit.
| Current | New | Difference |
|---|
| Shows | Actual speed |
|---|
Same 17" wheel, within 20 mm of width and 10 points of aspect ratio.
| Size | Diameter | Width | Sidewall | vs 255/75R17 | |
|---|---|---|---|---|---|
| 275/70R17 | 32.2" | 10.8" | 7.6" | +0.3% | compare |
| 235/80R17 | 31.8" | 9.3" | 7.4" | −0.8% | |
| 245/80R17 | 32.4" | 9.6" | 7.7" | +1.2% | |
| 265/70R17 | 31.6" | 10.4" | 7.3" | −1.4% | compare |
| 245/75R17 | 31.5" | 9.6" | 7.2" | −1.8% | |
| 265/75R17 | 32.6" | 10.4" | 7.8" | +1.8% | |
| 235/85R17 | 32.7" | 9.3" | 7.9" | +2.1% | |
| 275/65R17 | 31.1" | 10.8" | 7.0" | −3.1% | |
| 255/70R17 | 31.1" | 10.0" | 7.0" | −3.1% | compare |
| 255/80R17 | 33.1" | 10.0" | 8.0" | +3.1% |
Sizes within 2% of 32.1" on 18" or 16" or 15" wheels.
| Size | Diameter | Width | Sidewall | vs 255/75R17 | |
|---|---|---|---|---|---|
| 255/70R18 | 32.1" | 10.0" | 7.0" | −0.0% | |
| 255/80R16 | 32.1" | 10.0" | 8.0" | +0.0% | |
| 255/85R15 | 32.1" | 10.0" | 8.5" | +0.0% | |
| 275/65R18 | 32.1" | 10.8" | 7.0" | +0.0% | |
| 32x11.50R15 | 32.0" | 11.5" | 8.5" | −0.2% | |
| 295/60R18 | 31.9" | 11.6" | 7.0" | −0.4% |
Actual speed when the speedometer is calibrated for 255/75R17.
| Speedometer shows | on 255/70R17 | on 265/70R17 | on 285/70R17 |
|---|---|---|---|
| 30 mph | 29.1 mph | 29.6 mph | 30.6 mph |
| 45 mph | 43.6 mph | 44.4 mph | 45.9 mph |
| 60 mph | 58.1 mph | 59.2 mph | 61.2 mph |
| 70 mph | 67.8 mph | 69.0 mph | 71.4 mph |
32.1 inches (814 mm). The sidewall is 7.5 inches.
10.0 inches (255 mm) section width, measured sidewall to sidewall.
About 32.1x10.0R17.
255/70R17 is −3.1% in diameter, more than the common 3% guideline, so expect a speedometer error and check clearance. It is 0.0" wider.