I have a 05 Xfire Convertable, The manual seems to indicate the Tire Pressure Monitor System is standard.
Right? I have never seen the dash (low pressure)light on at anytime. The car had 9000 mi on it when purchased, but I now see there are typical Shrader valves on the stock rims. What's going on? Mileage is
low so, I assume the tires are original. I don't have the required sensors on any of the tire valves.
Questions:

• Is the pressure system standard or optional?
• If standard, why does the pressure lite never show up, even on start up?
• What may be the explanation for standard Shrader valves and no TMS valves? The car is in mint conditon. Everything looks stock and new.
• I don't want to spend a bunch of money on valve sensors to find the car doesn't have the system.
• I could leave well enough alone, but what concerns me is that the low profile tires don't go down much when low or flat and one could ruin a tire quick by driving on a low tire.