After my 15K service, I noticed a bumpier ride than before the tires were rotated. I returned the car to the dealership, and the diagnostician said that it looked like I will soon be needing tires. (I have faithfully brought in the car for the 5, 10, and 15K services). He claims that Lexus RX350 uses high performance tires, and 15 to 20K is all you can expect. Does this sound right? He also said he would recommend putting better tires, like Michelins, on the car. I replied, "you mean the Goodyears that Lexus put on, aren't so good?"