Reducing Road Noise

Prime is already pretty quiet but the OEM tires, depending on which ones you got, can be pretty noisy. I'll deal with that once mine wear out.

 

i would start with tires. michelin energy savers are virtually silent.
gen 4 is supposed to be quieter, but i don't know what they've done exactly. look inside the door panels to see if they've added sound deadening material.

 

Energy savers are expensive for 15" tires!

 

no question, mine were $500. installed. but they are sweet, and will last as long as i keep the car.
budget minded might want to look at the ecopia line.

 

I just bought michellin Xi3, and I'm going to mount them on my stocks. Then maybe try to sell the stock Toyo tires and get aftermarket 16's or 17's for next spring.

Trying to find an affordable 17x7 that is lightweight is hard.

 

i put 17" michelin premiers on my wife's hycam. they were $700. installed.

 

TJX,

Congrats on the Prime its a great car but road noise is a definite problem. Evey (my Prime) is considerably worse than Ema (my 2006 Prius). I never owned a Starfleet version (Gen3) so can't compare it but did purchase a Gen4 for business and drove it several thousand miles before handing it off to an employee as a company car. Ema is the quietest by far, Evey and the Gen4 are pretty close with Evey being a little more quiet but not much.

They both need a good Dynamat, Hushmat, Second Skin base followed by some MLV and even some HMF probably if you want it to be really quiet. That would all be interior work. Not sure if a good GMuff spray on the wheel wells would stay. It wore off on Ema after 25,000 - 40,000 miles or so and I never did it again. I only ever put Dynamat in Ema but was happy but MLV would have been nice to add as well.

Surprised how little thought went into making such a high end vehicle with all the tech and accessories at least a little bit quiet. Of course they missed some other things as well like drivers seat memory and folding mirrors. I am also surprised someone hasn't gotten killed yet with all the Nav issues with Bluetooth. Why someone would actually design a program to create distracted driving is beyond me.

Your best bet if you aren't going to do the sound deadening yourself is a local car audio or custom shop. They probably have the most experience in applying the stuff and can make recommendations. Here is a link I used for research: Sound Deadener Showdown | Your Vehicle Quiet

Good luck and happy driving,
Chris

 

New owner here with 3 weeks use only.
I have driven mostly on highways and do notice road noise (my other car is Acura MDX which is fairly quiet).
I did check the link provided above but materials alone would be $700, I can't imagine labor less than $500-1000 range.
If anyone has done simple sound proofing I would love to know. I am handy with car repairs as long as step by step instructions are there

 

you must be loving the gas savings.

 

I think the first thing you should do is post here exactly what brand and model of tires you have on it.
And maybe what pressure you are running with.
Then maybe other owners who have experience with those tires can give you an idea of what
improvement you might see/hear by getting different tires.

 

Basically, the Prime has been designed to minimize weight in order to maximize fuel efficiency and range. The weight of thicker body panels and sound-deadening materials would negatively affected the EV (and HV) range of the Prime.

As mentioned elsewhere, you can do some things like installing quieter tires than the OEM tires provided. You also can add various coatings to body panels to dampen noise and to seal out exterior sounds. And you may get some benefit from adding sound-absorbent materials inside the cabin.

There are many threads on this topic in PriusChat. Here are a few:

Sound Deadening Toyota Prius...Very Helpful! | PriusChat
Prius sound proofing | PriusChat
Soundproofing Prius Prime | PriusChat
Prius Prime detailed sound proofing procedure. | PriusChat
[VIDEO] Prius Prime sound proofing and road test compare | PriusChat

Regardless of what you do, it's unlikely that you will be able to achieve the sound isolation of a large and heavy luxury car. Such are the laws of physics.