I have a 2007 and a 2009 Hyundai Sonata and, living in New England, feel it is prudent to use dedicated winter tires. I purchased wheels along with the snow tires for the 2007 so as not to bother with seasonal changes; note that the 2007 does not have TPMs (Tire Pressure Monitors). Now I am ready to purchase wheels and tires for the 2009 and see that I can also purchase TPMs for an additional cost of about $200. I’d like to save the money and I regularly check my air pressure - Other than the light on the dash, is there any other system that will be affected by not having TPMs installed?
I believe that one or two regular posters said they don’t have TPMS on their winter wheel set. They said it’s so they know they have their winter tires on their vehicle, and the mechanics they talked to said no real harm was done, except maybe burning out the alert light prematurely. 
Thanks for the info. I was worried that the TPM light would disable the Stability or Traction control. Guess I can save a few hundred $s when I order those tires and wheels.
If your car uses the “indirect” TPM system, then it’s part of the ABS / stability control system. Changing tires and wheels will not have any effect on it. It will still work.
If it’s a “direct” system with pressure sensors inside the tires, there still should not be any problem as “no signal” means everything is OK…