[Hamidak]

Hello Bimmer fans , I purchased a used 2017 BMW 540i M Sport from a Land Rover dealership about 6 months ago, At the time vehicle had 55K miles, tires were about 70% left ( really cheap tires ) and brake had 9 MM left ( according to the dealer inspection ). I now have 59K miles, I’ve noticed 2 days ago my steering shaking really bad as I apply brake and according to a friend of mine that test drove my car he stated Rotors are bad and you have to change your pads, rotors & sensors. Also yesterday I had my TMPS light on for a rear driver tire being low on pressure , took it to a local discount tire and they mentioned my car doesn’t have original tire size. On top of that my rear tire is cracked ( Picture below ).
I need your expertise to figure out should I go back to stock size Tires or keep the same ones?
Also do you think tire crack could’ve caused for the same reason and I have bad rear rotors as well ?

Looking forward to learn from you guys
Thanks in advance

[tjbuggy2b]

That looks to me like it was driven on low pressure. You can see discoloration before and after where that crack is. 285/30 is one of the stock tire sizes. So, it's really up to you. If you're in a pothole heavy area, I'd go with a taller sidewall. If potholes aren't a concern where you are, then you should be fine with the same size as what you have.

For brakes, look up the rotor spec on how much lip there can be on the edge of the rotor. If have too much lip, or the wear pattern on the rotor is strange, then I'd replace the rotors. If you need rotors, you need pads. You can replace pads without replacing rotors, but I wouldn't replace rotors and not pads. You won't be able to get the pads to bed properly.

Wear sensor is always "required." However, IMO, if you don't see any wear markings on the sensor, why replace it?