I have a 12/14 delivered P85D. I have always heard a slight whine with light acceleration which is louder with heave acceleration. I did notice that if I turn off range mode after reading the above, there is still a audible noise but a lot of the high pitch part of the whine is markedly diminished. I had always assumed the slight whine was normal. I have never driven anyone else's Tesla, there is no local service, so even when I have had the car serviced you get a rental car, as there are no loaners.