192Best 255/40 R18 tires
93 rated tires available in this size, scored on dry, wet, snow, comfort and wear. Top overall right now is the Michelin Pilot Super Sport at 92/100.
26″
overall diameter
10″
section width
18″
rim diameter
774.8
revs per mile
Best 255/40 R18 summer tires
50192
289
389
486
584
683
782
883
982
1089
1181
128138 more rated tires in this size are listed on their brand pages.
More top-rated 255/40 R18 tires
17
188
290
388
488
584
684
783
884
983
1083
1193
12865 more rated tires in this size are listed on their brand pages.
Best 255/40 R18 all-season tires
16
189
288
386
486
584
684
782
884
980
12754 more rated tires in this size are listed on their brand pages.
Best 255/40 R18 winter tires
10
180
280
379
478
576
675
1075Conversion
255/40 R18 in inches
| Overall diameter | 26″ |
| Section width | 10″ |
| Rim diameter | 18″ |
| Sidewall height | 102 mm |
| Circumference | 81.8″ |
| Revolutions per mile | 774.8 |
The closest flotation size is 28x12.00R18 — 7.6% taller and 19.5% wider. Compare them in the calculator.
Wheels
What rims fit 255/40 R18 tires?
A tire fits a range of rim widths. Too narrow or too wide and the sidewall changes shape.
Minimum
7″
Ideal
8″
Maximum
9″
Rim diameter is fixed at 18″ — only the width varies. Estimated from the 10″ section width (70–90% rule).
Fitted from the factory on rims: 18x7.5, 18x8, 18x8.5, 18x9, 18x9.5, 18x10, 18x10.5.
Popular comparisons
Sizes often compared with 255/40 R18
Close alternatives — each opens in the tire size calculator.
Sidewall
255/40 R18 — what does it mean?
| Parameter | Meaning |
|---|---|
| 255 | The first number is the section width — 255 mm, or about 10 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 102 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. |