When is a tire placed out of service?

Jul 22, 2016 0 Comments in Uncategorized by


Reminder of the week:

When is a tire placed out of service?

Answer: FMCSA regulations appendix G addresses tire out of service conditions on each commercial motor vehicle as follows:

Any tire on any steering axle of a power unit.

  1. With less than 4/32-inch (steer) 2/32-inch (drive) tread when measured at any point on a major tread groove.
  2. Has body ply or belt material exposed through the tread or sidewall.
  3. Has any tread or sidewall separation.
  4. Has a cut where the ply or belt material is exposed.
  5. Labeled “Not for Highway Use” or displaying other marking which would exclude use on steering axle.
  6. A tube-type radial tire without radial tube stems markings. These markings include a red band around the tube stem, the word “radial” embossed in metal stems, or the word “radial” molded in rubber stems.
  7. Mixing bias and radial tires on the same axle.
  8. Tire flap protrudes through valve slot in rim and touches stem.
  9. Re-grooved tire except motor vehicles used solely in urban or suburban service (see exception in §393.75(e)).
  10. Boot, blowout patch or other ply repair.
  11. Weight carried exceeds tire load limit. This includes overloaded tire resulting from low air pressure.
  12. Tire is flat or has noticeable (e.g., can be heard or felt) leak.
  13. Any bus equipped with recapped or retreaded tire(s).
  14. So mounted or inflated that it comes in contact with any part of the vehicle.

Tires are designed to run at a given load and inflation pressure. Running 18 tires 30% under inflated will cost you 5% in actual vehicle fuel economy. 10% under inflation will be a ONE 1% penalty in fuel and 20% under inflation will be over 2% loss in fuel economy. Commercial motor vehicles that are used daily should have tire pressures checked daily. During an inspection drivers should check air pressures with a calibrated Gauge.

The practice of striking a tire with an object is NOT recommended and is inaccurate in determining inflation pressure.


Klemens Kuqi

Compliance Manger