As part of the effort to increase awareness of the need to maintain
proper tire pressure,
the U.S. government has taken steps to make it easier for
drivers to be aware of potentially unsafe low pressure in their tires. As of the
2008 model year, the National Highway Traffic Safety Administration (NHTSA) now
requires that all passenger cars and light trucks feature the Tire Pressure
Monitoring System (TPMS). In conjunction with the new requirements, the Alliance
of Automobile Manufacturers (AAM) has initiated a consumer safety campaign
focusing on the importance of maintaining proper tire pressure.
TPMS is an automated system that monitors the air pressure in a vehicle's tires.
When air pressure in one or more tires drops 25 percent or more below the
correct pressure, a warning indicator alerts the driver. TPMS typically delivers
these alerts to the driver through one of two types of warning lights on
the dashboard.
1. The first uses the official TPMS symbol, which is a cross-section of a tire with
an exclamation mark in the center.
2. The second is a top-view graphic image of a car that indicates which tires are low.
Tire pressure is monitored through one of two methods: direct or indirect. Direct
TPMS monitors the actual air pressure inside each tire via a sensor mounted
within the tire. Indirect TPMS measures tire pressure by monitoring the speed
and rotation of each individual wheel. When a significant variation in speed and
rotation is detected in one or more wheels when compared with the others, it is
often an indication of underinflation. This information is then transmitted to
the vehicle's on-board computer, and the driver is alerted.
However, while TPMS systems offer increased safety to drivers through low
pressure warnings, they are not meant to be a substitute for proper tire
pressure maintenance. Both the NHTSA and the AAM urge drivers to check their
tire pressure at least once a month and always prior to a long trip.
Be sure to read our article on the importance
of correct air pressure as well for even more in-depth information.
Even though TPMS has only recently become standard for all vehicles, a number of
older models already have them installed. Approximately 20 percent of 2006
vehicle models came pre-equipped with TPMS, and that number increased to 70
percent in the 2007 model year. If you are unaware if your vehicle has TPMS
installed, check your vehicle owner's manual. Discount Tire Direct offers TPMS sensor
kits for virtually all vehicles on the road, TPMS rebuild kits, and retrofit
kits for vehicles not factory equipped with a TPMS system.
