Recently our 2008 AWD Edge with 85000 km on it has started making an unusual sound while driving. It's only heard while in motion and to describe it would be to say it sounds like the sound you would get on dry pavement if you had just put on new tires. I do have four newer Michelin Truck Tires on it but the sound is new. It's a steady sound and although not a grinding sound it's more of a constant hum. It slows as the vehicle does and increases as the vehicle does.
Any ideas?