tiggerfink

One of our friends just purchased a new Infinety M45sport. He was bragging about how quiet it was and other things. On the way home, my wife mention that our SL is whole lot quieter than his new car. I said, I thought his car was loud.

So I got home and looked in my Motor Trend, Car&Driver, and Road&Track for interior cabin noise. I was excited to find out that the SL65 was at 66 dBA and the M45 was at 67 dBA at a cruising speed of 70 MPHs. Below are some of the interior noise levels at 70mphs.

Acura RL 69 dBA
BMW 530i 64 dBA
Jaguar S-type 65 dBA
Lexus GS430 63 dBA
Mercedes E350 64 dBA

lorinserbenz

Having owned an Infiniti (G35C) I can vouch for the loud cabin noise.
I test drove the new M45 and thought it was loud for a lux sedan..

LovinMercedes

I have found that the SL, even given the fact that it is a hardtop convertible, is still amazingly quiet.

tiggerfink

I wonder how loud is the jag convertiable? I found some more numbers.

Mercedes SLK55 72 dBA
Ford Mustang GT Convertiable 74 dBA

Trimmer2

Those numbers must be on fresh rubber! I think the noise goes up conciderably as the performance tires age...

tiggerfink

I have over 18,500 miles on my tires. The car is still quiet.

CASL55

I've got an SL55, so I may have different results just based on that. I have about 7000 on the original set of 18-inch P-Zero Rossos. At about 3000 miles, it got noisy, but it hasn't gotten any worse since. When I'm driving, the noise appears to come from the left rear tire.

In another couple of thousand miles, I'll be ready for new tires. If you don't mind telling me, what kind do you have that are so quiet?

Jim

tiggerfink

I have the original 18" Michelin Pilot Sports that came on the car. I do find it odd that I have to get my tires balanced every 6 months.

The tires are a little over 18,500 miles and looks like they can go another 18,000 miles. I put in 2 to 3 PSIs over recommended and check the balance every 6 months. Tires of that size usually do not stay in balance long.

I have the same luck on tires on my SLK 320. Those Michelin Pilot Sports lasted a little over 35,000 miles. The Michelin Pilot Primacy tires that I have now on my SLK 320 are noisy. I cannot get the Michelin Pilot Sports any more on my SLK320, because Michelin lower the rated load index to 87.