I'm looking to buy a 2004 that's in fantastic shape except for a road noise. I mean this is not just the normal tire noise that most sports type cars exhibit but one that get's very loud as speed increases. I'm really leaning toward defective tires but after reading numerous threads about this type of noise, it sounds like it could be caused by a number of other things.

The tires are 17" Protenza's that have way to much tread left to be the originals. The present owner bought the car 2 years ago with 30K on it and has added another 40K of mostly highway miles without changing the tires. He stated the noise has gradually gotten worse over the last 10K miles. The tread wear is even with no feathering but there are a lot of small cracks in the sidewalls.

I will most likely have it checked at a reputable tire shop or Nissan dealer before buying but thought I would get some opinions here first.

 

I would say they are coming from the tires. It is a big problem on the Z since the entire fender wells are inside the cabin. Get yourself some good summer tires. Hankook ventus V12 Evo is proven to do very well for lots of members. I fully sound-deadened my car when i did my audio and just recently srayed some rubberized undercoating in the wells. Made a huge difference. The ultimate solution is new tires. They are on my budget when car comes out out winter hibernation

 

Cracks on the sidewall is an issue. It can be several of these...

Running tire on low air ( but not low enough for them to blow)
Tire is really dry on the outside or inside or both.
Internal structural issues.
This was also very common in the shop with cars that were parked for a long time.

What year were these made? ( last 4 numbers on the DOT # on sidewall = week and year) You are probably better off getting 4 new ones honestly.

try discount tire direct, or tire rack and take em to a local tire place to get them mounted and balanced.

While they have your car up, tell em to check the suspension bushings just in case.

 

More than likely the previous owner replaced the tires with OEM Bridgestones.
Take it from me,these are very noisy tires.Even ever so slight cupping will make them sing.The tread pattern itslf is noisy.If there are cracks in the sidwall I'd sure replace e'm.
Depending on your budget,lokk at going to a 18" wheel&tire .Better yet,19' if you
don't track your car.Slap on some Hankook V-12's and you'll be driving a new car.

 

Summer/Performance tires are very noisy. Don’t base your decisions on the noise generated by these tires.

--Spike

 

Have a professional check your alignment and verify the conditon of the tires as well

Cracked sidewalls can come from overuse of tire dressing or the previous owner may have purchased used and old tires

 

Stock Bridgestone RE050s are very noisy, I didn't realize it until I swapped them for some Nitto Invos on the back and the car got so much quieter inside.

It's the tires, plan on replacing them and use something quieter if it suits you. I have RE-11's on mine now and they are still quieter then the RE050's while delivering stellar performance all around superior to the 050s. Or you could use an S0-4 as a much more well-rounded tire, smooth and silent, have a set on the wife's Sonic and they are great.

Even a cheaper RE760 like I have on my Tercel will be acceptable, and quieter than the 050 although you won't get as much performance at the limit in dry weather.

 

All the input is greatly appreciated. The consensus seems to be the noise is being caused, in most part, by defective tires. I'm still in the process of negotiating with the seller on price and will definitely use the cost of tire replacement as a bargaining chip.