189Best 285/40 R18 tires
4 rated tires available in this size, scored on dry, wet, snow, comfort and wear. Top overall right now is the Continental ExtremeContact Sport at 89/100.
27″
overall diameter
11.2″
section width
18″
rim diameter
747.6
revs per mile
Best 285/40 R18 summer tires
4189
284
379
468Conversion
285/40 R18 in inches
| Overall diameter | 27″ |
| Section width | 11.2″ |
| Rim diameter | 18″ |
| Sidewall height | 114 mm |
| Circumference | 84.7″ |
| Revolutions per mile | 747.6 |
The closest flotation size is 28x12.00R18 — 3.8% taller and 6.9% wider. Compare them in the calculator.
Wheels
What rims fit 285/40 R18 tires?
A tire fits a range of rim widths. Too narrow or too wide and the sidewall changes shape.
Minimum
8″
Ideal
9″
Maximum
10″
Rim diameter is fixed at 18″ — only the width varies. Estimated from the 11.2″ section width (70–90% rule).
Fitted from the factory on rims: 18x9.5, 18x10.5.
Sidewall
285/40 R18 — what does it mean?
| Parameter | Meaning |
|---|---|
| 285 | The first number is the section width — 285 mm, or about 11.2 inches across the widest part of the tire. |
| 40 | The second number is the aspect ratio: sidewall height as a percentage of width. At 40%, the sidewall is about 114 mm tall. |
| R18 | R means radial construction, which nearly all modern tires use. The number is the rim diameter in inches — this tire fits a 18-inch wheel. |