jason g

There has much discussion on this forum about the noise generated by runflats and which tire is better than another. I and others have pointed out that it is invalid to compare noise generated from a new tire to that from a worn tire and, as a result, it is very difficult to make valid comparisons.

I chose to go with Firestone's Firehawk SZ50EP RFT tires several months ago, primarily because they were touted as a better tire in the rain, so much cheaper than Goodyear's, and because so many had expressed that they were quieter tires (since no one stated that they were noisier tires, I assumed that they were no worse than the Goodyear's). Like so many others have reported, these tires WERE much quieter than the Goodyear's that the car came with AT THE TIME THEY NEEDED TO BE REPLACED.

However, over the last several weeks I have noticed a great deal of "tire noise" (sounds like the tire noise from a passing semi), which seems to be coming exclusively from the back. I only hear it at speeds greater than 40 mph. My Firestone's have approximately 9,000 miles on them and seem to be wearing normally. Without a doubt, the noise I am now hearing from these tires (if that is all this noise can be) is much greater than what the Goodyear's ever produced, even during their darkest hour. This noise appeared a couple of weeks after I had a leaking differential repaired, but I have been back to the dealership and assured that the noise is unrelated to that repair. An inspection of likely causes was performed and all was ok - the differential fluid level is correct. The weather was pretty constant during the period that the noise became apparent, so I don't think it is temperature-related either (something the dealer stated was true of all these tires - noisier as the temperatures drop).

I've read here that some have heard similar noise, but that they have isolated the problem to their hub bearings rather than the tire. I've yet to try fast turning maneuvers to determine whether that is my case as well, but find it hard to believe that what I am hearing could be anything other than noise from the tires. It really has a distinct sound.

Others on this forum have pointed out that all runflats are going to make more noise after they have worn in, and someone has pointed out that the GM alignment specs. will cause the tires to wear-in in such a way that they are likely to generate tire noise (a condition that may not be necessary for cars that are not being raced, though we all like to race at some level, I'm sure). This may all be true.

A year ago, not many people had Firestone's on their C5's long enough to be able to comment on the noise they generate (other than when they were pretty much new). I would appreciate everyone having a careful listen (pretend that you are being passed by a semi - do you hear it??) and letting us all know whether anything has changed. If any tire noise is heard, what does it sound like, and does it seem to be the same, worse or better than the noise from the original Goodyear's (when they were about as equally worn or more worn)?

As I searched for answers to this problem, I was reminded what a great forum this is. There are so many extremely helpful members with a great wealth of knowledge and experience to share. Two quick examples and then I will shut up. I had my first crippling column-lock experience last month (hadn't had the recall performed since I never experienced it) and was amazed (but not surprised) to find that someone had recently posted a workaround for the problem, sparing me the experience of a first tow. Two weeks ago, my battery died (is 4 years normal?) and I was equally amazed to find that someone had posted the procedure for obtaining the security code for the stereo, which is needed after a power loss. Thanks don't go far enough! (It just occured to me, I'm having a hell of a time recently; but still love this car.)

Thanks in advance for your input on the tires.

pewter99

Had mine for over a year and still love them...haven't noticed that they are noisy

4THTOY

I am on my 2nd set of rears, the first went 29K miles, I heard a small increase in noise, but still much lower than the GY's. I like the 'stones" so much I bought another set, after these wear down, I don't know what I will pick. I want a runflat due to the number of miles a day I drive, and the strange hours.

SteveL2

I had my Firestones put on when my GY's were brand new -- yep, the 1st day I owned by car. IMO, the 'stones are quieter. They now have 21k on them, and the rears really need replacing :crazy:, and I would agree that they are noisier than they were new. However, I still would not say that they sound at all like you're describing, so I'm thinking you have an issue other than the tires. Good luck. :seeya

C5 StockSwap

SteveL2: When did you get those fuel rail covers? Very :cool:

Busted Knuckle

I'll Bet Those Fuel Rail Covers Came From Noel @ Autobuffs. Just a guess :lol: :lol: :lol: :D :cheers: :flag

Bill Dearborn

When I first installed Firestone RFTs last year I noticed an increased growling noise. I originally thought the noise was coming from the tires. Then I put my treadless Kumho's on and drove around the area for a few minutes and the noise was still there. Now I am about to have my second wheel bearing replaced. Replacing the first one reduced the noise, however, after my last track event it is very apparent the noise in the rear is worse and the shop agrees it is a rear wheel bearing. They are just not sure which one.
Bill

Sixguns

The tires can be checked to see if they may be the cause of your noise. Have you ever looked at your tires to see some tread blocks are dark and others not? perhaps after driving over a dirty or wet surface some tread blocks will show that they are not touching the pavement, that the tire has cuped tread.

wet your driveway, carefully drive your car over the wet surface makeing only one rotation of the tires and take a look.. if you see wet and dry tread blocks its safe to assume your tires are the cause.


[Modified by Sixguns, 7:28 PM 10/18/2002]

00FRCBlue

Just FYI, I swapped out my GY runflats when they were at 90% (9/32") fronts and 80% (8/32") rears - almost new condition. There was and still is a marked reduction in road noise. There were just under 6K miles when I changed them. The Firestones are now at about the same mileage the GYs were and still new-ish. However, I have no data on well worn tires in either case.

SteveL2

And a mighty fine guess at that. :yesnod: Yep, Noel is the man. :smash: Newer pics with more under-the-hood goodies to follow. :seeya