Road Noise

I find new tires are usually always quiet, just when they wear down, they get noisier

 

My brand new Ecopias are super loud. Like 70 dB in the cabin as measured on an iPhone. Other tires are probably quieter but you'll lose MPG. The LRR tires are stiff, that's part of what makes them LRR... they have less sidewall flex.

 

FWIW on my 2022 XLE Nightshade I find the Ecopias fairly smooth and quiet (17 inch rims) running at recommended pressures.

 

The Prius is an innately loud car. I’m guessing that some sound deadening will give you better bang for the buck than new tires.

there was a post somewhere on this forum where a guy showed that you don’t have to sound deaden the bejesus out of everything for near optimal results. That is, a few strategically positioned “mat” give you a huge increase in quiet, and after that you’re looking at diminishing returns.

 

There is definitely variance from tire to tire. I bought mine used about a year ago - and I test drove a few, on all kinds of tires. I definitely noted that one particular car, which was on Michelins felt a good bit quieter than what the car I actually bought (on some brand I never heard of before and can't tell you now without going to look at them). Or it could have just been the roads near that dealer, but I doubt it.

 

I've worn out four sets of Goodyear ComforTred tires during my Prius adventure and all of them were exceptionally quiet. Goodyear put a layer some sound absorbing material in the build-up. They were quiet all the way down to 4/32". I see they aren't making them anymore, which is a shame. I'm coming up on the time for new tires on my '21 now, currently at 61K. I know I won't go OEM with the Toyo Nanoenergy which are a good mpg tire but rather noisy. So begins my search.

 

My 22' XLE didn't sound quite as loud as my 19', but I'm not sure if the tires had much to do with it. None the less, I did add a good amount of sound deadener in all 4 doors and the whole trunk area.
It did help a TON... Which makes my aftermarket stereo system sound that much better / cleaner
It's true that you don't have to fill every panel with a ton of sound deadener though. Diminishing returns for sure. Honestly I think if a person could "finagle" a couple square feet into each door, roof, trunk area, etc it would be a big plus ! .... because you don't just "put" sound deadener in > you "struggle" it in ! Biggest PITA job in the history of jobs ! But SO worth it

 

I covered my entire trunk floor with sound deadener - because that was the easy part to get to. It didn't do much.

I agree that most of the noise comes from the front wheel wells and the doors.

 

I do need to do my front wheel wells. How tough are they to uncover in our Gen 4's ?
Maybe I'll get some more deadener to have on hand for the next time I visit my mechanic / friend. I always have extra jobs for him, even if I'm just there for an oil change He usually doesn't even charge me, but I always tip him accordingly