They‘re tires, just huge. All cars have tires yet I only hear that whirrrrring sound on those trucks with huge tires.
Big Trucks With Big Tires
Big tires usually have big treads. If you look at your tires on your car, you will notice that the tread is either small blocks, or waves that go around the tire. On off road tires the tread is made up of big blocks so it will grip in dirt and mud. Each time one of those blocks hit the asphalt it makes a sound. Like hitting a drum. You don't notice the noise when the truck is going slow, but once it speeds up the treads are hitting the ground hard enough and fast enough that they make that whirring sound.
When the build up gets bad you use a straight edge razor blade to scrape it off. Don't use to much of the white cleaner either it is not good for the stove.
My mom says that if you mix baking soda and water into a paste and clean the top of the stove with it, the spots should come off and it will be really shiny. The only thing is that you have to rinse it a bit to get the baking soda off.
It's all in the tread pattern, offroad designed tires as put on truck enthusiast have knobby tread which grabs onto dirt and mud and whatever else is unfortunate to get under them. On the road these hit the ground and make a pronounced noise especially at interstate speeds (and of course higher). Car tires can make noise too, mostly run flat tires and from what I've seen a lot of Bridgestone Potenzas. You probably wouldn't notice it unless you were driving a well sound insulated car as wind noise can easily cover this up. My grandmothers car (a Nissan Maxima) the rear tires drive me nuts.
