I am hearing and feeling a vibration

In my vehicle listed above I am hearing and feeling a vibration. I feel it in the floorboards of both drivers and passengers side. I also feel it in the steering wheel. Along with feeling it, I also hear it. It’s hard to exactly describe the feeling or noise. It’s not like the brakes are rubbing or the tires are not balanced or anything like that. It kind of sounds like 4 wheel drive is always on - or kind of like some mechanical gears don’t have enough oil. It just doesn’t seem to roll down the road as smooth as I expect. Like I said, it’s hard to explain.

I guess my question would be about the SmartTrack 4 wheel drive system. Generally how does it work? Could there be a sensor out causing it to be engaged? I’m reaching for straws now.

I’m getting 17 MPG in town, which seems to be correct.

Thanks.