Many Audi owners looking for a Winter / Snow Tire & Wheel Package this season question whether or not their vehicle is equipped with TPMS sensors. While TPMS has been required on all new vehicles sold in the United States since 2007, not all models use a directly mounted transmitter type pressure sensor to relay this data.
On many new Audi models, especially those made after 2010, tire pressure is monitored based off of rotational speed. When a tire loses air pressure, the rotational speed of that tire is changed, and while 1-2 psi will not make a large enough difference to trip the system, a loss of perhaps 5-10 psi will. Once the difference in rotational speed is noted by the vehicle's wheel speed sensor, a message is then passed along to the driver.
This new type of ABS monitoring isn't quite as accurate, however it enables customers to purchase a new wheel and tire set without also purchasing direct TPMS sensors.
To find out if your car requires direct TPMS sensors, simply search by vehicle.