I installed them on a 2008 Audi A8l, the old sensors showed zero months of battery life. They were easy to install. I tested the new sensors with a Bar-Tec TPMS scanner. All sensors showed a battery life of 72 months. I reinstalled the TPM system in the MMI. I pulled up a screen in the MMI that showed the individual tire pressures, after about 3 miles the screen showed the readings from all 5 sensors. I spent about $125 for 5 new sensors, I was able to buy one at the dealer for the same price. I have a 2010 Audi A8l. If this car needs TPM sensors, I'll buy another set of Mobiletron sensors.