Can anyone with experience with this car on chip-sealed or other high noise freeways comment on the interior sound level at cruising speeds of 65 to 75 MPH?

I currently own a Porsche 911 C4 GTS that is great fun, but has limited practicality. If that were the only issue, I would be less concerned. However, I recently moved to the Pacific Northwest where almost all the freeways are chip-sealed. For those that don't know, chip-sealed roads create huge amounts of tire noise. I believe that at 70 MPH on the really bad roads in my area, the interior sound level is above 80 decibels. For drives longer than 20 minutes, I have been forced to wear ear plugs to avoid hearing loss.

If the GT 63 S is significantly quieter, I may consider trading in the Porsche. The GT 63 S appears to be almost as fast on several race tracks (according to results on fastestlaps.com) and is far more practical as it can hold 4 normal size humans and lots of luggage. Now the only issue is whether I can drive it in my part of the world without needing ear plugs.

By comparison, my wife's Tesla Model 3 Performance is sufficiently quiet on these same roads that I can hear the radio quite clearly at a very reasonable volume. Thus, it is clear that at least some cars are capable of filtering out the tire noise from these terrible roads.

TIA

 

Overall I find the GT 63 S pretty quite but I wouldn't say it's S class or Cadillac quiet. It does a good job filtering out noise of all sorts and find it comfortable on most road surfaces. Part of the issue is a high performance tire, running sport cup 2's for example won't be as quiet as a touring tire but that takes away the performance. The Tesla runs an all season Michelin primacy for stock rubber. This alone would be far quieter to ride on vs say the GT's sport cups. I would think the GT is definitely more insulated then a the 911 as it was designed as a grand touring car but all that performance comes with some cost in noise or suspension stiffness.

I would say go take one on a test drive is going to be the best way to find out if it's liveable. With room for 4 (if you need that), luggage space, a bit quieter cockpit and softer more compliant ride and certainly a better stereo would be a better touring car vs the Porsche. Don't get me wrong though the Porsche is an amazing performer and beautiful car but not exactly friendly for day to day commuting or even traveling. It's a performance first design as most Porsche in the 911 category are bred to be. The GT is more of a touring car that has amazing performance thereby making a bit more livable, but it's not perfect either. For me the small tradeoff's in noise or a little stiffness more than make up for the rest that it does spectacularly.

 

Thanks for the feedback. Just a few points to clarify.

1. The Tesla Model 3 Performance comes with 20" wheels with Michelin PS4S tires which are not sport cup 2s but are serious performance tires that are not noted for quiet or soft rides. Given that the Tesla has enough sound insulation to make the terrible roads tolerable shows it is possible.

2. The Porsche was just fine when I lived in North Carolina with real asphalt roads. The problem is these terrible roads in the Pacific Northwest.

I will likely go for a test drive, but I don't want to waste my dealer's time if I get feedback that the GT is very loud on rough freeways.

 

For what it’s worth, the CNET (and I think Road and Track) review had a major knock on it being too loud

 

I can't speak specifically for the GT and I don't drive on chip-sealed pavement very much. There's a short stretch near my house, but for the most part our roads have been repaved over the last decade or so with what's called rubberized asphalt. For those that don't know it, it's a mixture of asphalt and the rubber/compound from shredded scrap tires. Not only does it make the asphalt last a lot longer, but it dramatically reduces tire noise and improves ride comfort.

I can help you understand the situation a bit better, though. Performance tires make noise over chip-sealed pavement. The wider the tire, the nosier they are and the shorter the sidewall the more of the noise is transferred to the interior. While your wife's Model 3 has performance tires, they are skinnier, but most importantly inside of the tire is an acoustic foam that dramatically reduces road noise. That's a fairly new technology that tire manufactures such as Michelin, Pirelli etc. offer in some of their tires.

https://www.teslarati.com/tesla-tire...ise-reduction/

The German car manufactures have started to do this in their higher trim performance cars as well. I believe the first one was Audi with the RS7. I don't know what AMG puts on the GT 4-door, but this is basically where you need to start. Getting a set of tires with acoustic foam is your best bet to reduce tire noise. Not sure if Michelin etc. offer anything in the sizes needed for the GT 4 -door, though.

 

A few more general thoughts/tips. Basically, this situation largely comes down to the choice of tires. Aside from the acoustic foam technology in Tesla's etc. some tires are inherently noisier than others. What make/model tires are currently on your Porsche? If it's the Pirelli P Zero, then be aware that those or some of the noisiest performance tires you can get. Especially once they have reached about half of their thread life. I had them on my RS5 and while I liked them from a performance standpoint, they were the noisiest street tires I've ever used. I switched to Michelin PSS and now PS4S and my C63S came with PSS which I will soon replace with a set of PS4S. Pretty much night and day between the P Zero and both Michelins. I've had the PSS on several of my cars. Great tire, but the PS4S is on a different level. So it might be time to put something different on your Porsche. And just in general, the older and more worn the tire, the noisier they get, so just putting on a new set could make a big difference.

The other thing is tire pressure. If it's too high, your tire will be stiffer and produce/transfer more road noise. Many people are not aware that the recommended pressure on the door sticker in the USA only lists what's called the max load recommended tire pressure. This one is meant for when the car is fully loaded with passengers and cargo. Might not make that much of a difference in a 911 given the limited passenger and cargo space, but usually there's something called the normal load recommended tire pressure that is meant for regular driving with just the driver, maybe one passenger and little cargo. It's lower than what's on the door sticker and not only improves ride comfort, but also tire wear and noise. Not sure where Porsche puts the additional recommended tire pressures, but if it's like Audi and other VW Group entities, then it's in the owner's manual. Mercedes puts a more detailed sticker inside of the fuel door and using the right tire pressure can make a world of a difference. Below as an example is the sticker from my C63S. As you can see there's a wide range of tire pressures depending on number of passengers, amount of cargo and desired top speed. Using the wrong tire pressure for the situation makes the car drive like crap, so very important to use the correct pressure for overall comfort, noise and desired performance.

 

I would honestly say for something like this your best bet is to go drive one. As all of us will have different opinion and our personal level of what we find acceptable is in now way able to be compared to what you find acceptable therefore your best course is to go and drive one on said pavement and see if it's annoying. I'm sure you certainly don't want to spend $180k on a car and then go spend another $3k putting new tires on it to make it quieter.

As mentioned above the Model 3 tires aren't just your run of the mill off the shelves and they are thinner. In addition the model 3 happens to have an enormous battery back that doubles as a floor so instead of 1/8' of aluminum and some insulation under your feet you have an 8" stack of batteries, insulation and carpet blocking out road noise and that is something no other combustion car has, I mean the entire floor is one huge insulator from the road and it's where most of the weight of the car resides. If you find that amenable I would say go with the Tesla Model S. You get 10 second 1/4 mile, almost 300 miles of range, all the creature comforts and it's about $40k less than the GT63S similarly equipped. Since you like the quietness and ride of the Model 3 your more than likely love the Model S.

The GT63 is a bit noisy and based on your feedback probably wouldn't be to your liking. But the only way to be sure is... Drive it... Besides isn't that the fun part of being a car enthusiast! Go drive them all!

 

My comment here would be my GT63s has no more interior sound to my previous E63s. Previous cars I've had in a similar vein was the Audi RS6, which it would hard to distinguish from the Mercs in interior noise frankly, maybe a tiny bit louder at that. The GT wouldn't be of course as quiet as the Bentayga but its not night and day either. My wife has driven both and road noise between the two didn't even rate a mention given she drives the Bentayga daily.

Hope that's of help

 

How does the gt63s compare to the e63s?

 

The E63S is quieter because it's a Sedan with lots of insulation between the cabin and the trunk. The GT63 is basically a hatchback so you get a bit more noise than the E63. I had an E63S before my GT63 so I'm pretty familiar.