Q: I have a compact car, a Toyota Yaris, and although I love the thing it's kind of loud on the freeway. Is there any way I can quiet down the cabin noise? A: The noise heard in the cabin of any car comes from three general sources: the mechanical bits, the wind, and the tires. If everything with the engine, suspension, and exhaust is in proper working order, most of the noises in a regular commuter car like a Yaris come from either the wind or the tires. You can address both of these sources with fairly simple solutions. The easiest way to cut down on noises entering the cabin is with sound deadening. Your car already comes with some in strategic places, but since it's a low-cost compact there are undoubtedly areas that can be improved.
We recommend 3M Sound Deadening Pads, a new product that costs $14 a roll. The idea with this thin new stuff is to use it like a shock-absorbing sticker and soak up the noise-making vibrations that transfer into the cabin. Installation is done by cutting out patches and sticking them to key spots on the sheet metal. The easiest places are the firewall and floor because you can get to them from outside the car and without removing any parts. If you're adventurous, remove the inner door panels, carpet, and headliner, then stick deadener on the inside of the outer door skin, floor, and bottom of the roof panel.
Another, more expensive solution is to fit quieter tires next time your rubber wears out. Many retailers and online reviews rate tires by how much noise they generate.
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