[pshadoa]

I have been wondering if a "rubberized" undercoating in the plastic wheel wells would reduce tire noise. Thoughts ???
I live in the San Diego area which has a very mild climate. No snow, very little rain.

 

[pshadoa]

I used a liquid truck bed liner. Bed liner coating I removed my wheel liners (on my MDX) and painted 2 coats on their hidden side.
Here's youtube video...Trust this guy's videos

Thank you for the idea! Did you find the coating reduced tire noise? I switched to 18" Ridgeline wheels and what Tire Rack and Discount stores (several of each) told me were the quietest all-season tires available. But I have very sensitive hearing, and while others that ride in the PP say the tires are " whisper" quiet, I find the tire noise to be irritating. This after trying two different brands of the recommended "quietest " tires.

 

[pshadoa]

When I replaced my 20" wheels with 18"s I first tried the Continental Contact LX25s. I thought they were noisy even though having a 8.8 rating for noise. So I replaced them with the Pirelli Scorpion Verde Plus II tires that have a 9.3 noise rating. I too used a Db meter and both tires were about the same. Supposedly my old Touring wheels had a foam noise reducing strip around the inside of the wheel. I never saw them w/o tires mounted so I do not know for sure. If so, maybe that is why I feel these new tires are noisier. I previously replaced the door speakers with better ones and put sound deadening material in the doors. So just drive with the audio turned up !

 

[pshadoa]

I read Honda's research info on sound deadening road noise the 20" Passport rims have a sound deadening strip, but didn't know how well they worked until your comment.
Road noise goes down as the amount of rubber, between the rim and the road increases.
You mention the Db levels were the same, between your OEM 20s (with sound deadening strip) and that of new 18s (without the sound deadening feature). Effectively, the sound deadening strip equates to having more rubber between the rim and the road.
Now I need to find out if any Honda/Acura 18" rims have the sound deadening strip and can be used on my Passport. I haven't checked the rims sizes on newer Hondas/Acura, which might be designed to be more sound conscience.
More on Honda's R&D road noise

Thank you for posting the info re the sound deadening strips. It was very interesting!