After you drive it, go to each wheel and feel for significant heat differences among them, sounds like a brake may be dragging, regarding the fuel miliage.
The hum may be a wheel bearing going bad, does it change if you steer to the left or to the right?
If those spark plugs are original, I get those changed. But not untl the first two problems are resolved.
Tuesday, February 6th, 2007 AT 9:01 PM