31.8" tall, 9.3" wide, 7.4" sidewall
A 235/80R17 tire is 31.8 inches (808 mm) tall and 9.3 inches wide. The sidewall is 80% of the width, 7.4 inches, on a 17-inch wheel, and the tire turns about 634 times per mile.
In flotation terms that is about 31.8x9.3R17. People often call it a 32-inch tire.
The size most often compared with it is 255/80R17, which is 1.3" taller (+4.0%). At an indicated 60 mph you would be doing 62.4 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 235/80R17 | |
|---|---|---|---|---|---|
| 255/75R17 | 32.1" | 10.0" | 7.5" | +0.8% | |
| 245/75R17 | 31.5" | 9.6" | 7.2" | −1.1% | compare |
| 225/80R17 | 31.2" | 8.9" | 7.1" | −2.0% | |
| 245/80R17 | 32.4" | 9.6" | 7.7" | +2.0% | |
| 255/70R17 | 31.1" | 10.0" | 7.0" | −2.4% | |
| 235/85R17 | 32.7" | 9.3" | 7.9" | +2.9% | |
| 255/80R17 | 33.1" | 10.0" | 8.0" | +4.0% | compare |
| 245/70R17 | 30.5" | 9.6" | 6.8" | −4.1% | compare |
| 225/75R17 | 30.3" | 8.9" | 6.6" | −4.8% | |
| 245/85R17 | 33.4" | 9.6" | 8.2" | +5.0% |
Sizes within 2% of 31.8" on 15" or 16" or 18" wheels.
| Size | Diameter | Width | Sidewall | vs 235/80R17 | |
|---|---|---|---|---|---|
| 305/70R15 | 31.8" | 12.0" | 8.4" | +0.0% | |
| 285/75R15 | 31.8" | 11.2" | 8.4" | +0.1% | |
| 235/85R16 | 31.7" | 9.3" | 7.9" | −0.2% | |
| 235/75R18 | 31.9" | 9.3" | 6.9" | +0.2% | |
| 285/70R16 | 31.7" | 11.2" | 7.9" | −0.3% | |
| 295/60R18 | 31.9" | 11.6" | 7.0" | +0.4% |
Actual speed when the speedometer is calibrated for 235/80R17.
| Speedometer shows | on 255/80R17 | on 245/75R17 | on 265/70R17 |
|---|---|---|---|
| 30 mph | 31.2 mph | 29.7 mph | 29.8 mph |
| 45 mph | 46.8 mph | 44.5 mph | 44.7 mph |
| 60 mph | 62.4 mph | 59.4 mph | 59.6 mph |
| 70 mph | 72.8 mph | 69.3 mph | 69.6 mph |
31.8 inches (808 mm). The sidewall is 7.4 inches.
9.3 inches (235 mm) section width, measured sidewall to sidewall.
About 31.8x9.3R17.
255/80R17 is +4.0% in diameter, more than the common 3% guideline, so expect a speedometer error and check clearance. It is 0.8" wider.