Whistling sound with Snow Tires

[juddy987]

Experts,

I have 2006 X5 4.4. Just changed the factory wheels (255/55 R18) with all seasons to BMW 5 spoke style 57 wheels with Nokian snow tires (235/65 R17) - recommended size and wheels...
Now I drive it on the highway and I get a whistling sound as though you get from large trucks...the sound is definitely coming from the wheels/tires not from the engine compartment...there was no sound with factory wheels and tires...

Any suggestions what could it be...I have BMW recommended pressure settings on the snow 32 front and 33 rear...

Help!!

Judd