Hello to everybody
I do have question and I will appreciate if somebody get any idea to help me.
I bought a new BMW X5 only has 3000 miles on it. It's came with original BMW tires 19' and I upgraded them to 315/35/20 rear and 275/40/20 front. Since I replaced with the new ones I started to hear noises and the lights for flat tires warning lights went on. What should I do swap it with the original 19' or I do have any other problem that I am not able to figure it out.

The best thing you can do is ask at your dealership. Another place to ask is the Tire Rack.

There might be a sensor problem with your new rims. Might want to take it to the place where you got them and ask them about it.

Did you have new TPMS sensors installed in your new wheels? If not, you have your answer. The TPMS system is effectively disabled if there are no sensors in the wheels for the system to read. That's illegal by the way.