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What You Should Know About the TREAD Act
Congress passed the Transportation Recall Enhancement, Accountability and Documentations Act, also called the TREAD Act, in 2000 in response to a major recall of defective tires that created unsafe driving conditions.

The TREAD Act (Federal Motor Vehicle Safety Standard 138) mandates that every new vehicle, less than 10,000 pounds gross vehicle weight (GVW), sold in the U.S. be equipped with a tire pressure monitoring system, or TPMS, beginning with the 2006 model year. TPMS alerts drivers when the pressure in a tire falls more than 25% below the manufacturer's recommended tire pressure. The TREAD Act affects passenger cars, light trucks and buses. Vehicles under 10,000 lbs GVW with dual-rear axles are excluded.

There are significant differences between direct and indirect TPMS technology:

Direct TPMS systems include small sensors that are installed inside each of the tires. These sensors accurately monitor tire pressure and continuously relay this information, via radio signals, to the vehicle's electronic control unit (ECU). If tire pressure falls below required limits, a warning light on the instrument panel alerts the driver about the problem.

Indirect TPMS systems use the vehicle's ABS system to calculate the difference in tire diameters and approximate tire pressure. An additional downside of indirect technology is that it can register a fault if all four tires are low (which often happens in cold weather) and will likely always indicate low tire pressure when driving on a spare tire (which may be of different diameter than other slightly worn tires).

Make It Easy to Teach Your Staff About the TREAD Act
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Scroll down for more information about the TREAD Act and what it requires.

The TREAD Act required vehicle manufacturers to equip 20% of their 2006 model year vehicles with TPMS. The number increased to 70% of 2007 model vehicles and to 100% of all 2008 models and beyond.

System Performance Requirements
The TREAD Act outlines a number of specific TPMS performance requirements:

  • New vehicles must be equipped with sensors that monitor tire pressure in all four tires. Monitoring the spare is not required.
  • The TPMS system must operate when the vehicle ignition is on and warn when tires are underinflated by 25% or more.
  • The TPMS system must alert the driver when there is a system malfunction.
  • The TPMS warning light must stay on until the tire is inflated to the proper pressure or the system malfunction is corrected.
  • A "bulb check" of the warning light on the instrument panel must occur whenever the ignition is turned on.
  • Vehicle owner's manuals must contain warnings about potential incompatible replacement tires for the vehicle.

TPMS Saves Lives
Most people ignore their tires, yet tires are undoubtedly a critical safety component on a vehicle. Where the rubber meets the road affects traction, handling, steering, stability and braking. Because of this, a sudden tire failure can have serious consequences, especially if it occurs when operating at highway speeds.

  • According to NHTSA, nearly 250,000 accidents occur in the United States per year due to low tire pressure.
  • About 75% of roadside flats are preceded by a slow leak or underinflation (
  • According to a recent survey, America could reduce its fuel consumption by 10% and save a collective $2 billion a year by keeping tires properly inflated.
  • A tire can lose up to half of its air pressure without appearing to be underinflated (NHTSA).
  • NHTSA estimates that 660 fatalities and 33,000 injuries each year are attributable to crashes caused by underinflated tires.