The LS 460 L is a super quiet car, no doubt about that.
But there is always room for improvement.

Here's what I've tried so far. Please share your own DIY tips.

Road noise:
Acoustic cotton in spare tire well. I used "Echo Eliminator" from Bonded Logic, but it is very similar to the "shoddy pad" used in cars, especially by BMW. Stuffed approx 15 panels into cracks and crevices, topped with rubber mat.
Result: as with my BMW X3, minor but noticeable reduction in road noise from the rear. At the moment road noise appears to come from the front of the vehicle.

Replaced OEM Bridgestone Turanza EL42 with Pirelli P7 AS Plus 3.
Result: marked improvement in road noise. Road noise is almost imperceptible on good roads.

Wind noise:
Applied two coats of Gummi Pflege treatment to all seals
Result: no auditory change despite visual improvement of some worn seals.

Next:
Front wheel well noise reduction (link below)
Add more acoustic material to voids within the car.

I will consider recordings with spectral analysis going forward. Also looking for some hyper directional mechanic microphones for determining the source of noise. Otherwise, it makes sense to take hints from Lexus's findings (article below), and NVH techniques used in the latest ultra luxury vehicles.

Research:
How the Lexus LS 600h Became the World's Quietest Passenger Car
DIY Mobile Audio - 3 step wheel well noise reduction procedure

 

Get rid of that weather tech mat and get deep poke carpeted mats inside as well, that cuts down on noise a lot

 

The only noise that bothers me is the damn high pressure fuel pumps tapping away and a whine from the transmission. The transmission mount was replaced originally and this helped but it's coming back again. Dealer has been no help with either!

 

An absorption/mass loaded vinyl sandwich was another thought.

For me road noise can become an issue due to sensitive hearing, coarse roads, and high speeds. I do wish the engine was muted like the 400/430, but for me that mostly disappears into the background.
Perhaps the firewall could be reinforced? An audio installer might have experience there.

 

The mice are going to love that nest you made them under the spare.

 

I’m going to post pics of the stuff I bought for my 460 to put under the wheel well liner.

I already have some butyl-rubber pads that I added to the plastic liners to help reduce the noise, but I purchased a 3-1 Hybrid mats that also contains mass loaded vinyl and closed-cell foam all in one pad so I’m going to try that out and see if the tire noise is reduced even more. My car is already really quiet by me simply replacing the tires recently.

You can’t add anything to the rear wheel well since it’s already done in felt so you can’t stick these pads onto them without it falling off. You could try using some 3M adhesive spray on the felt liner, and then try sticking the pads on, but I personally don’t want to do that.

 

Depending on how in depth you want to get this RX likely is as quiet or quieter than our LS's. Stripping the interior including headliner out to install the sound deadening material takes some dedication.
https://www.clublexus.com/forums/rx-...h-project.html

 

Alright guys, so I finally installed the additional sound insulation pads on the wheel well liners.

And man! What a vast improvement it made at reducing road noise on the freeway. Even my girlfriend told me while we were talking on the phone yesterday that she could barely hear any tire noise in the car while I was doing 80-85 mph on the freeway.

Prior to even installing new tires on my car, it did have some road noise especially on the crappy neglected concrete freeways in San Diego. I mean my LS460 is already pretty quiet, but now the road noise is much more “hushed” than before, I actually hear more wind noise than road noise now lol.

On asphalt, the car is completely silent! It’s crazy.

So I would definitely recommend installing these pads if you want an even more quieter car.

The first thing I installed was the Siless 3-1 Hybrid pads which adds mass and then I covered it over with their Closed Cell foam pads for additional sound absorption.

It was very easy to do, and the pads stick very well to the liner. Just be sure to really clean off the dirt and grime from the liner for better adhesion.

I only added 1 layer of each material because I already had old rubber pads I used on the liner a year ago, plus my new tires are slightly taller 55 series, so I have less clearance. You could add maybe 2 to even 3 layers depending on the tire clearance because you don’t want the tires rubbing on the pads if there’s too many layers

1. jack up the car.

2. Clean off any dirt from the wheel well plastic liner for better adhesion. I simply used Invisible glass cleaner which worked great.

3.Cut pieces to fit, it doesn’t have to be perfect. I messed up and covered over the screws to remove the liner in case you need to replace the headlights. So keep that mind.

4. Get yourself a metal roller that it used to roll on dynamat or any sound deadening material pads. This is a must if you want to make sure the pads stick for good and don’t ever fall off.

Thats about it, if you don’t like the grey look of the foam pads, you could always use some black undercoating spray to cover it up and make it look like there’s nothing there which I plan on doing.

Hope that helps.

 

The roads bother me too. I had a nice ES350 but went to the LS because of road noise. Those that can ignore the noise are fortunate. Nice post.

 

Question - is it possible to apply all these extra layers on the inside of the fender liner?

 

The LS will always be a quieter car than the ES
hands down.

 

I am not entirely sure, but it could be possible. I figured adding the pads on the liners themselves was the easiest, most effective and cleanest option.

 

I wouldn’t be able to handle that all stuck to the outside of the liners, I would have to put them on the inside.

 

Yeah, I am curious if this can be added to the inside area with perhaps a fastening hardware change.

 

Those pads are going to peel and fall off in no time. Did you consider removing your wheel well liners to stick the sound deadening on the inside.