The 911 with 19" wheels seems to have a lot of tire roar on Highways

When speccing a 911 base does getting 18" wheels help on the highway from a road noise perspective?

Thanks

 

Tread pattern, wear life, and tire composition will impact noise. Wheel size shouldn't make a difference. Tirerack does a good job of rating tires for noise level.

 

I don't notice the road noise, I guess my exhaust is louder then the tires.

 

I thought larger wheels/tires contribute to more road noise in the same brand of tire eg: 18" wheels vs 19" wheels on OEM michelin PS2

I guess if ordering a 911 C4 and dont care for 19" wheels , does the std 18" wheels better for highway in terms of road noise with PASM option?

 

Any difference should be negligable as we're talking about low profile performance tires. If the profile was significantly larger on the 18's or running an all-season type tire that may change the equation, but you wouldn't do either for a Porsche.

I don't know specifically which wheels you're considering but the 19's may be a little wider and therefore have more contact patch which 'could' result in slightly more road noise as the tread wears. But again, I don't think it will make that much of a difference. I only have experience with the 19's so maybe someone that has run both can shed light. I do believe that the PS2's with full tread are generally the quietest. They also have a good wear life.

 

I have OEM PS2 with about 900 miles on them now and .... they are loud. I guess that's what you get for 305-wide tires. I will try a different brand when it's time.

 

I think the nature of the design of the 911 will make all tires loud. I have the OEM Pirelli 305's and they are loud. It's a matter of which is the quietest which may or may not be a moot point.

+1 the exaust sound is intoxicating and overrides the tire noise.

 

PS2s here on 18's - loud from day one on concrete - asphalt is much better. At any rate, I don't think 18s are going to help you much. Best to look at Tire ratings as suggested.

FWIW, I ran PS2 on all my M BMWs and never thought about noise. The P-car is just a noisy ruffian.

 

Actually I noticed that after putting spacers on the car (7/15), there seemed to be more pronounced tire noise (in both cases with the top down). I assume it's because more of the tire is 'unshielded' from the fender. Not kiddin'.
OTOH, it could all be in my head...
However, the tire noise has really diminished since I put in the x-pipe.

 

The Carrera is not a quiet plush soft car so road noise will not be like a Mercedes, Cadillac or Lexus.

 

+1 Carreras are not meant to be luxury cars. They are high performance sports cars.

 

I thought the 997 was a touch loud until I got a ride in the new Nissan 370Z!! OMG is it loud!! The vette is pretty bad too. Then I started thinking about how quiet the 997 actually was. There is very little sound insulation in the car and I think that it makes it sensitive to small changes like tire brands and alignment. Go to tire rack and find quiet tires! My PS2s are not bad yet with 4000 miles (they are not chunked or scrubbed, however). I heard that the bridgestones are a tad quieter than the PS2, but I have not verified that......

 

may be you need to check your alignment and make sure if your car does not have too much toe in.

 

This is true BTW.

 

I have always thought the noise in the 911 was little oppressive and fatiguing.

I don't really like loud exhausts, that is why I have the combo I do;AWE headers and cats with a Remus exhaust. I certainly hear the engine better inside the car and I think it sounds better outside the car.
It just is not really loud like I found the complete AWE system to be for me.

All this being said, tolerance to noise is an individual thing. I think I have a low tolerance.

One of the things about the noise in the 911 I have always not liked is a booming type of resonance that I found irritating.

That being said I find regardless of the brand (in my experience Pirelli or Michelin) as the tires wear out near the end of their life they get very noisey.

I recently changed my rear PS2's out and left the half worn fronts on.

I had some Dynamat "extreme" laying around (and I have never wanted to tear apart the insides to add some of this) so I knocked on the car in a few places like the inner fenders. There is no sound deadening there so I decided to add some. I put some Dynamat on each inner fender closes to the passenger compartment ,on the front lower plastic panel under the steering box, and on the plastic under the transmission. Note; I didn't try to cover every square inch at all.

The Dynamat Extreme has a foil layer that traps sound. Same idea that Ford and I think Lexus use in their Quiet steel built into their cars and or trucks.

Knocking on a panel with and with out the sound deadening there is noticeable difference.

I notice a nice difference inside the car too.

But is it the new rear tires or a combination of the two?

The booming resonance seems to be gone.

I won't really know until the tires are worn. But at this point I am happy with the difference.

Probably added about 5lbs of weight at the most and it is very easy to do with no negative effects. I will take the rear seats out to balance out the weight gain.