I just got a new (CPO) GTS today! Went for a long drive and was so enjoying the naturally aspirated symphony #8 that I never even turned on the stereo. However, after awhile while at speed on smooth roads I noticed this faint but definitely there steady sound whose pitch was correlated with my speed. I would describe it exactly like the sound a turbofan jet engine makes, especially during takeoff. (Just much much quieter than on a plane

For reference, I've appended a link to a video of a DC-10 taking off. At 2:43 when the engines are throttled up, you here a chopping noise kick in which remains all during the takeoff. Not the high-pitched whine of the jet, but a lower more grumbly, choppy kind of sound.

At first I thought it might be the tires, but now I'm not sure. It could just be a natural engine noise that just happens to make its way into the a-pillars as part of the exhaust note. I was just curious of others had heard the same thing. Like I say, it's quite subtle. Probably turning on the stereo at nearly any volume would drown it out.

 

After driving around some more, I'm more convinced it is the tires. The car came with the 20" Michelin Pilot Sport A/S all-seasons. Anyone else have these?

I'll be putting some summer tires on it soon, so we'll see what happens then.

 

Sounds about right. No whirring noise from my PGTS and it is surprisingly quiet in the highway with SottoZeros. I imagine that my MPS summer tires will make a bit of noise, however.