Can acoustic insulation cut down on tire noise?

One unpleasant aspect of driving is the noise that permeates the vehicle cabin. The tires can be a major source of this racket, producing a droning hum during regular travel as well as other commotion while traveling over potholes, expansion joints, and other obstacles.

A quiet ride can be a major selling point for a vehicle, so automakers and tire manufacturers are always striving to keep things quiet. Eric Adams, writing for Wired, says quieter tires tend to have poorer handling. However, there is an ongoing effort to improve this balance, especially as the quieter drivetrains of electric vehicles make tires a more prominent source of road noise.

One popular option for reducing noise from tires is acoustic insulation. Both Michelin and Continental use strips of polyurethane foam affixed to the inside of a tire to help dampen sounds. Michelin says the foam helps reduce the resonance of compressed air inside the tire. Continental says the foam is not detrimental to driving performance and is not affected by temperature changes, but is only available for summer tires.

The companies say the insulation can help cut cabin noise by 20 percent or by as much as nine decibels, depending on road conditions. However, drivers may not notice too much of a change. Car and Driver tested two sets of tires with polyurethane insulation in 2016 and found that their noise levels were not significantly different from tires without insulation.

Tire noise may also be a result of irregularities with the tire. Logan Woodworth, writing for Tire Rack, says tires with uneven wear will no longer have uniform tread depth and produce louder noises. Even if the tread is wearing evenly, the tire will likely get louder as the rubber gets closer to the steel belt.

Other factors related to the tires can also increase noise levels. Port Charlotte Honda, a Florida dealership, says the tires will create more noise if they are out of alignment. A bad wheel bearing can also produce noise, especially when you change lanes.

Underinflated tires will also be louder, so it's important to regularly check the pressure and inflate your tires as needed. Make sure you also follow the recommended maintenance schedule for tire rotation and alignment.