A lot of noise comes from what you're driving on. As far as improving efficiency goes - I assume you mean miles/gallon or per kwh? The average driver doesn't

A lot of noise comes from what you're driving on. As far as improving efficiency goes - I assume you mean miles/gallon or per kwh? The average driver doesn't pay attention to tires until they become flat or don't pass inspection. Keeping them properly inflated, rotating, and periodic alignments will help efficiency more than a different tire. I have to imaging tire companies would be all over some new tech that would increase mpg. What type of giant impact are you envisioning?