Tire hum or???

I have an 08 Tacoma double cab 4 w d auto. I bought it last may with 86k miles.
Runs FINE!
Previous vehicle was a 95 Tacoma with 285 K miles and running great but I needed the full back seat room.

About Three month ago I bought a set of Michelin Xts tires as the originals were getting a bit thin. The new tires ride and feel great, but I can hear and feel (in the steering wheel) a slight hum/vibration , mostly at 45-50 mph on any smooth road surface, wet or dry. As I said it is "slight" but I am keenly sensantive to vibs.

My local Auto Tech has road tested it and thinks that it may be tire noise but he is not sure. Tire dealer says he has had no issues with these tires and has sold many sets over the past years. I had installed them on my 95 Taco and did not notice any "hum" and i know that the 2008 truck is quieter overall.
Any thoughts?

Thanks, Alpine bob

 

Rotate the tires and see if the hum/vibe changes. Or even, change the tire pressure temporarily to see if anything changes. By doing this, could narrow it down to the tires.

The new tires could actually hum......as part of the tire design. The vibration could be a balance issue - since you just got them installed..??

 

My cheap ass 245 Dunlop's just started doing this about month ago. I know these tires couldn't hum if they wanted to. But it honestly sounds like I have a set of 285 MT's on now. Usually does it anywhere from 30mph +

Never thought about the wheel bearing Jamie, I guess that gives me somewhere to start.

 

And btw mine DOES NOT sound like this video of a wheel bearing going bad http://www.youtube.com/watch?v=gL1dl_M0Nxs It's just a slight hum which you can only really hear when the radio is off

 

Thanks all for the replies.
I have had tires rotated and balanced at Discount, they run very smoothly so I know the balance is good. I raised the tire pressure from 35 to 40 Psi, no difference in the sound.
Today, I tried coasting in neutral , engine off, engine on, no difference at the "hum speed" of 45-50 Mph. had a buddy ride shotgun and he heard the hum too.
I don't suspect a wheel bearing because the hum is very smooth not grating as a bearing will sound.
In four thousand miles 90K I will have both front and rear differentials drained and refilled with synthetic lube, so I will not do it until then.
As to the comment on the radio, I cant hear the hum with the radio on, or with a window open. It is really a low volume hum which seems to be totally speed related leading me toward tire vibration resonating somewhere in the body/chassis???
alpinebob