I need you guys to lay it to me straight.
I got a Fit GE6 in February. I love the car.
However I'm living in rural Japan surrounded by rough roads.
I have hyperacusis. I travel at speeds of 40-100kmh. The road noise on rough surfaces is so jarring it causes me pain and tinnitus at times. I tried changing the tires from Radars to Bluearth-GT. The noise got even worse to where I had to change back to the old tires and now I'm stuck with new tires I can't use. I test rode(can't test drive here) a 2010 Prius touring. It was noticeably quieter at 100kmh and on the rough surface wasn't as jarring despite wearing 17inch wheels. I would look into a bigger sedan, but the streets here are so small I'm already going to loose access to some if I change to a Prius(a sedan even more).

My question is can I save my Fit via extensive sound deadening or is it better to consider it a lost cause and buy a Prius 30 instead (Prius 50 is still on the $$$ side)

Thanks

 

Hi.
About two years ago I did extensive sound deadening work on a 2010 GE8 (US) Fit Sport. I also have sensitive hearing so was willing to put in significant work to improve the car. I can go into as much detail as you want, but briefly:

1) I dismantled and removed the interior, except for the dash, A pillar trim, and headliner.

2) I used two products, both from Siless: an 80 mil foil-backed butyl sound deadening followed by a 157 mil sound deadening foam, with the idea being that the butyl deadener would absorb vibration and the foam would block sound intrusion. These products were applied on all accessible interior surfaces, including under and behind the dashboard as far as I could reach. The butyl deadener was not applied as a complete layer and was focused on areas of potential vibration (based on research I did). The foam was applied as a complete layer and in a few areas like the inner doors and the rear hatch I applied two layers of foam.

The material cost was not that great (about $225), especially in comparison to my time investment as I worked on-and-off for at least 10 days and probably 40-50 hours. Maybe I'm slow, but you should be aware that this is time-consuming DIY work.

Was it worth it? The car is definitely quieter now, but it is still not as quiet as a more expensive "luxury" vehicle from the same era, let alone most new cars. I will say that my sister drives a 2014-ish Prius V (the US wagon version) and to my ears it is not any quieter inside than my Fit.

So, for my purposes it was a good time investment, but I don't know how that would translate to your ears and your roads. If the Prius your rode in was notably quieter *to you* then I think you already have your answer.

 

I appreciate your response friend!
I have to ask when you say her Prius V isn't any quieter then inside your Fit, is this before or after deadening? Because if it's after I imagine deadening a Prius will yield me better results then deadening a Fit...

Thank you friend!

 

To my ears, my sister's Prius V is not any quieter than my sound-deadened Fit. I never compared them directly before working on my Fit, but I think the Prius V would have been quieter in that comparison.

I agree that if your starting point is quieter, and then you add more sound deadening, you will end up with a better (quieter) result. It's also possible that a car with decent factory sound deadening and with a design more focused on a quiet ride will need less overall work for the same relative improvement. In other words, I added materials to most of the interior of the Fit (minus the roof, which I may eventually attempt), whereas another car might need improvement in only a few areas (e.g., the doors, the rear hatch, etc).

I forgot to mention before but there are many posts on FitFreak offering advice for making the Fit more quiet, with techniques ranging from installing sound deadening materials like I did, to making sure you have the rear parcel shelf in place (I don't have this), putting in better/thick floor mats (I have Weathertech front and rear), or even putting a heavy blanket under the rear seat (I haven't tried this either). Another topic I found on FitFreak related to four underbody plugs that are often missing on Fits. In the case of US cars, they cover the shipping tie-down points and were supposed to be installed after the cars arrived at the dealer and before they were sold, but this often didn't happen. Supposedly having the plugs in place reduces road noise. My Fit was missing these plugs, which I was able to purchase from the local dealership for <$25. I did this after my sound deadening work and didn't notice any real change, but maybe without the sound deadening I would have.

I'm not saying that any of these fixes will solve your problem, but it's easy enough to try some of them (e.g., blanket under the rear seat) while you're figuring out how to proceed.

One final piece of advice if you do attempt to add sound deadening materials to any car. As you're removing the interior trim pay attention to how much room you have under the trim. In the Fit, there were a few trim pieces that were extremely difficult to re-install after my sound deadening additions. For example, the trim pieces around the rear hatch opening were a major struggle. If you get overzealous with sound deadening additions you might not be able to reinstall the factory trim pieces.