Upgrade OEM tires

Firstly, I doubt that Toyota evens warrants the OEM tires; that is Goodyear's problem. Check the little booklets in your owners' manual package. Also, check with your state bureau of auto repair or whatever the state warranty bureau is called there. I am under the impression that simply changing tires to an equivalent tire of the same or better rating will not void your car's warranty. It is not like you put giant 44" rims on it and distorted the suspension to make it fit. Whether the dealer wants to mess with it may be a different story, but in few times I have done it the dealer complied and no warranty issues arose. If the dealer persists in the myth of voiding warranty, call or email Toyota and then you may wish to do business elsewhere.
While ome tire stores will swap out OEM new tires and apply the trade for new tires, I doubt that you could get a very good deal.

As to the quality of the OEM tires, that is different story; I assume that they meet or exceed minimum requirements; any thing else is personal preference.

 

You might want to check out the other threads on upgrading tires for additional information on noise, comfort, and treadlife...

Personally, I was not comfortable with the Integrity tires after test-driving a Prius in the rain with them. I told my dealer before I picked up the car that I wanted to upgrade to the tires to the Goodyear ComforTreds (which I have and love), and was first told that they probably couldn't handle it through the dealership. I asked to speak to the Service Manager, explained that I wasn't comfortable with the OEM tires, and he said that he would work something out so that I only had to pay the difference to upgrade the tires, which worked out to be $24/tire plus mounting and balancing.

I got the call that my car was in (at a dealership in Bethesda, MD) on a Thursday, so I bought a plane ticket and flew out the next morning. The saleswoman had already dropped my car off at a tire place (Just Tires) to have the swap take place, and after picking my up at the airport, drove me directly to my car. I had to pay for the difference in the tires at the tire shop, but in the end I was much happier with the better tires.

Long story short - don't walk away with something that you're not completely satisfied with. While the dealership might not do the swap in house, they should be able to at least set up an appointment for you to have it done. The Toyota tire warranty most likely would not apply unless the dealership actually does the swap, but it sounds like your salesman is just being lazy in suggesting that you not change the tires. If he says that using other tires might invalidate anything but the tire warranty, you can tell him that Toyota itself doesn't endorse one brand/line of tire over another, that the distributor is the one with the contract, or simply that he's a liar.

Plenty of tire places with credit you the difference towards a better set of tires when you have new ones, particularly ones that carry Goodyear products. Shop around and see where you can get the best deal, and good luck!

 

Don't know if this is still true, but years ago I was told by an "expert" that OEM tires were of a better quality than the same make and model of tire sold in a tire store. OEM tires came of the same tire assembly line but were the product of a selection process where they were more perfect than run-of-the-mill production.

 

I purchased my Prius on 4th of July weekend - with 300 or so miles on the tires I went to my local Goodyear dealer. They took them off my hands and with an additional $300.00 I upgraded to the Triple treads and I also got the road hazzard coverage.