A 255/40R22 tire is 30.0″ tall and 10.0″ wide, and fits a 22″ wheel. In inches it is written 30.0×10.0R22.
Heights published by Michelin for all 2 tires in this size. Their published revolutions per mile work out to 29.1″ under load (below).
Real 255/40R22 tires measure 30.00–30.04″, against 30.03″ from the size code. They run both taller and shorter than the size code.
Published revs per mile (692) mean the tire rolls like a 29.1″ tire on the vehicle. Use this for speedometer calibration.
The lightest (Michelin Pilot Sport All-Season 4, XL) is 3.6 lb lighter per corner than the heaviest (Michelin X-Ice Snow+, XL).
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Yes. The size code works out to 30.03″, and the 2 tires here publish 30.00–30.04″, so people call it a 30.
All 30-inch tire sizes, on every wheel size.
Differences in overall diameter, calculated from each size code.
A percentage, not a measurement: the sidewall is 40% as tall as the tire is wide, which is 102.0 mm or 4.02 inches.
Radial construction.
Mounts on a 22-inch wheel. Approved wheel widths run 8.5″ to 10.0″.
Each tire carries up to 1,929 lb (875 kg) at its maximum pressure.
Rated for up to 149 mph sustained.
Printed after the size.
| Specification | Inches | Metric |
|---|---|---|
| Overall diameter | 30.03 | 763 mm |
| Section width | 10.04 | 255 mm |
| Sidewall height | 4.02 | 102.0 mm |
| Circumference | 94.3 | 2,396 mm |
| Revolutions per mile (calculated, unloaded) | 671.6 | 417 per km |
| Revolutions per mile (published by manufacturers) | 692 | 430 per km |
| Approved wheel width | 8.5–10.0 | 216–254 mm |
30.03 inches tall, 10.04 inches wide, on a 22-inch wheel. Written in inches, that is roughly 30.0×10.0R22.
Between 30.6 lb and 34.2 lb for the 2 tires listed here. The lightest is the Michelin Pilot Sport All-Season 4 (XL); the heaviest is the Michelin X-Ice Snow+ (XL).
Manufacturers approve 8.5–10.0″ wide wheels for this size.
Published figures run 692 revolutions per mile. The calculated figure is 671.6, but manufacturers measure the tire under load, where it rolls on a smaller radius.
0.18 inches taller on paper (30.03″ vs 29.85″), which raises the axle about 0.09″. Your speedometer will read about 0.6% slow.