99LS Cabin factory spec sound level in db
07-27-13, 06:30 PM
#2
Lots of factors come into play. Road conditions and tires are the greatest culprit. Sometimes I find the quieter the car the more I am annoyed by a little rattle. Like my rear armrest cup holders have a slight rattle when left in the upright position. Drives me crazy.... lol. I'll pull over and lower the thing.
07-27-13, 08:04 PM
#4
Best suggestion would be to get one of the phone apps that reads db or a db meter from Radio Shack and test for yourself. I don't find the cabin of the LS 400's to be particularly quiet. The auto writes waxed about the tomb like silence. They must have significant hearing loss if they thought the LS400 was like how they described it. 
Found some:
http://www.motortrend.com/roadtests/...t/viewall.html
http://www.motortrend.com/roadtests/...0/viewall.html
Found some:
http://www.motortrend.com/roadtests/...t/viewall.html
At 60 mph, we recorded a 64 dB reading inside the Lexus, while the Infiniti produced 66-still among the quietest production cars at any price.
Careful attention to sound-deadening materials paid off in a whisper-quiet interior that's a hair under 40 dB at idle and a mere 61 dB at 60 mph, when a hint of wind noise can be detected
07-28-13, 09:32 AM
#6
Lead Lap
Interior noise level depends on many things including wind speed and direction, pavement type and condition, tire model and condition; door and sunroof gasket condition and proper adjustment; windshield seal condition (i.e. proper installation if a replacement has been installed).
There was a TSIB long ago to address wind noise produced by the outside mirrors - the solution was to stuff and glue foam behind the mirror glass. All the foam applied under this TSIB came out of my mirrors long ago.
I noticed yesterday that my interior seemed nearly silent at 65 mph on very smooth pavement in zero wind conditions. I could just barely hear some engine noise if I listened closely. My tires are fairly new (*<20K miles) Michelin MXV4 in the standard size - very quiet tires. On rough pavement and in cross winds, my interior can seem pretty noisy.
My perception is that the interior has gotten a little noisier as the car has aged - bought it in 2003 at 38,000 miles .... now at 168,000 miles. I assume the door seals are a bit compressed. I occasionally lube them with silicon spray applied with a paper towel but I don't know if that helps. I had the driver door hinges replaced a few years back. The original owner/lessee had apparently had the door "adjusted" by having the hinges bent.
There was a TSIB long ago to address wind noise produced by the outside mirrors - the solution was to stuff and glue foam behind the mirror glass. All the foam applied under this TSIB came out of my mirrors long ago.
I noticed yesterday that my interior seemed nearly silent at 65 mph on very smooth pavement in zero wind conditions. I could just barely hear some engine noise if I listened closely. My tires are fairly new (*<20K miles) Michelin MXV4 in the standard size - very quiet tires. On rough pavement and in cross winds, my interior can seem pretty noisy.
My perception is that the interior has gotten a little noisier as the car has aged - bought it in 2003 at 38,000 miles .... now at 168,000 miles. I assume the door seals are a bit compressed. I occasionally lube them with silicon spray applied with a paper towel but I don't know if that helps. I had the driver door hinges replaced a few years back. The original owner/lessee had apparently had the door "adjusted" by having the hinges bent.
07-28-13, 01:32 PM
#7
Even when ours was much younger, I didn't feel it was as quiet a car as it should be. When it had stock wheels with the MX4V's the interior was quieter. Wound up putting some neoprene like material over the rear wheel arches and it may be good for 1/3 -1/2db attenuation at best...basically unnoticeable. 
BMW and MB seem quieter but they may have better attenuation at certain frequencies over our LS.
BMW and MB seem quieter but they may have better attenuation at certain frequencies over our LS.
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07-29-13, 03:36 PM
#10
Lexus Champion
08-01-13, 08:52 PM
#12
Just for grins i did a unscientific test today with my phone app. Highway speed 70mph no head wind. No head wind and i got 78db. I think its a bit high since i have a small wind noise on the drivers side. When i turned on the radio to what i like it went to 82db.
08-02-13, 04:01 AM
#13
Lead Lap
I think you have a problem with whatever device you are using to measure the sound level. My painfully noisey Mercedes Diesel was 77db at 70 mph and my LS400 is far quieter that it.
08-02-13, 05:35 AM
#14
Yeah, like i said unscientific. Those phone apps probably not real accurate. lol
78db said road noise and something else on the app. It didnt sound all that bad inside but i am sure could be better. 20 years has taken a small toll on weather stripping. May have to try that silicone stuff.
78db said road noise and something else on the app. It didnt sound all that bad inside but i am sure could be better. 20 years has taken a small toll on weather stripping. May have to try that silicone stuff.
08-02-13, 07:15 AM
#15
Yeah, like i said unscientific. Those phone apps probably not real accurate. lol
78db said road noise and something else on the app. It didnt sound all that bad inside but i am sure could be better. 20 years has taken a small toll on weather stripping. May have to try that silicone stuff.
78db said road noise and something else on the app. It didnt sound all that bad inside but i am sure could be better. 20 years has taken a small toll on weather stripping. May have to try that silicone stuff.