OEM tires on most new cars are garbage. They're generally spec tires and not the same tires you'd be able to go buy off the shelf. While my factory tires had plenty of tread left they were loud were starting to hydroplane on wet roads by 20k. Been basically the same experience in the past, 20-30k and it's time to drop them. With my newish (now have like 5k on them) Goodyears it's quieter, doesn't hydroplane, and getting better mileage as I could rarely break 30mpg, now it's bouncing between 32 and 33 on my commute and longer trips it's been up as far as 35.