• A Tire Pressure Sensor Buyer’s Guide

    A tire pressure sensor is a device that is installed on a vehicle’s wheel to report any changes to tire inflation, for the purpose of avoiding potential accidents. There are many benefits to driving with properly inflated tires, and while a tire pressure monitoring system is factory-installed on most newer model vehicles, aftermarket parts can be purchased for older models. There are several things to keep in mind when shopping for a tire pressure sensor.

    Direct Application of Tire Pressure Sensor

    A direct TPMS (tire pressure monitoring system) consists of a tire pressure sensor for each wheel that detects the actual tire pressure. These measurements and calculations are then transmitted via low power radio frequencies to a device which decodes the information and presents it in a way that is readable to the driver. If low pressure or other problems with a tire are detected, the signal is received in the form of an alert, usually to a device installed inside of the vehicle or attached to a keychain. Most direct tire pressure monitoring systems are sold aftermarket. Some believe that direct tire pressure sensors have several advantages:

    • Notifications for problems with a specific tire
    • Reprogrammable
    • Easily replaced
    • Battery operated
    • Fewer false positives, such as with rough terrain, mismatched tires or improper tire balance

    Indirect Tire Pressure Sensor

    An indirect tire pressure sensor is a form of monitoring that usually comes as original equipment installed by a vehicle manufacturer. These types of sensors use measurements of wheel rotation speeds to guess the amount of air that is presumed to be in the tire, based on the diameter of the tire and other factors. They usually depend upon the vehicle’s anti-lock braking system to determine the rotational speed of the wheel. This system can be rather unreliable for the following reasons:

    • Will not report if all four tires are underinflated
    • Will not report if two tires on the same axle are underinflated
    • Not reprogrammable
    • Not tire specific, guesswork involved
    • Less accurate
    • Valve stem sensors are difficult to replace

    Types of Aftermarket TPMS

    There are several types of aftermarket tire pressure sensor mechanisms that can be fitted to your vehicle. Each has advantages and disadvantages that may help you to determine which system is right for you. Some systems are much cheaper than others, but it may be beneficial for you to weigh the long-term savings involved by purchasing a high-quality tire pressure sensor. Knowing when you need to repair or replace a tire can help with gas mileage, help save on repairs and even help save your life. Following is an outline of advantages and disadvantages of some types of TPMS:

    • Flag Indicating – Cheap and easy to DIY fit to your wheels, but they are easy to steal, impossible to check unless driving and cannot be reprogrammed.
    • Wireless – Reads the actual tire pressure with many options, but these tend to be more expensive and cannot be fitted without a professional.
    • Internally Installed – May be more accurate, but more difficult to troubleshoot and replace.
    • Externally Installed – Easy to replace and battery operated, but can be unsightly and be easily damaged.