i just got mine yesterday and noticed the same type sound and also noticed it has 4 different tires all together on it. the sidewalls read:
front right) 265 70r16 111t
front left ) 265 70r16 112s- this tire is noticeably larger than the other 3
rear right ) 255 70r16 111s
rear left ) 265 70r16 109s
wtf, really? bought from a dealer this way, i can only hope it hasent been driven like this for a long time, very disappointing.
im going to check with some used tire shops around and see if i can trade these in towards the purchase of a full set of proper 245 70 16, im unsure about which T or S are needed tho