The tires that come on cars from the factory are built to different specifications than the same name and model tire you purchase at the tire store with the mileage guarantees. This has been going on for years. I've not yet had this happen on our honda as I only have about 4k miles on it at this point, but on every new BMW I've had and even Jeep, 15-20k mile tires are what the factories put on them. If you replace them with the exact same brand / model tires from say discount tire or another tire shop..you will get the milage out of them. Honda is doing exactly what every car company out there is doing.