26.6" tall, 12.0" wide, 4.8" sidewall
A 305/40R17 tire is 26.6 inches (676 mm) tall and 12.0 inches wide. The sidewall is 40% of the width, 4.8 inches, on a 17-inch wheel, and the tire turns about 758 times per mile.
In flotation terms that is about 26.6x12.0R17. People often call it a 27-inch tire.
The size most often compared with it is 295/40R17, which is 0.3" shorter (−1.2%). At an indicated 60 mph you would be doing 59.3 mph on it.
| 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 305/40R17 | |
|---|---|---|---|---|---|
| 295/40R17 | 26.3" | 11.6" | 4.6" | −1.2% | |
| 285/45R17 | 27.1" | 11.2" | 5.0" | +1.8% | |
| 285/40R17 | 26.0" | 11.2" | 4.5" | −2.4% | |
| 315/35R17 | 25.7" | 12.4" | 4.3" | −3.5% | |
| 325/45R17 | 28.5" | 12.8" | 5.8" | +7.2% | |
| 315/50R17 | 29.4" | 12.4" | 6.2" | +10.5% |
Sizes within 2% of 26.6" on 15" or 18" or 19" wheels.
| Size | Diameter | Width | Sidewall | vs 305/40R17 | |
|---|---|---|---|---|---|
| 295/50R15 | 26.6" | 11.6" | 5.8" | +0.0% | |
| 245/60R15 | 26.6" | 9.6" | 5.8" | −0.1% | |
| 275/40R18 | 26.7" | 10.8" | 4.3" | +0.2% | |
| 305/35R18 | 26.4" | 12.0" | 4.2" | −0.8% | |
| 215/70R15 | 26.9" | 8.5" | 5.9" | +0.9% | |
| 285/35R19 | 26.9" | 11.2" | 3.9" | +0.9% |
Actual speed when the speedometer is calibrated for 305/40R17.
| Speedometer shows | on 295/40R17 | on 285/45R17 | on 285/40R17 |
|---|---|---|---|
| 30 mph | 29.6 mph | 30.6 mph | 29.3 mph |
| 45 mph | 44.5 mph | 45.8 mph | 43.9 mph |
| 60 mph | 59.3 mph | 61.1 mph | 58.6 mph |
| 70 mph | 69.2 mph | 71.3 mph | 68.3 mph |
26.6 inches (676 mm). The sidewall is 4.8 inches.
12.0 inches (305 mm) section width, measured sidewall to sidewall.
About 26.6x12.0R17.
295/40R17 is −1.2% in diameter, within the common 3% guideline. It is 0.4" narrower.