Not sure if 18's would be any quieter than 20's just because normal manufactures buy cheap quality tires for their vehicles, sort of low to mid grade tires. On certain road surfaces my factory Michelin tires sound hollow, something I have not experience with higher quality tires in the past.

Not sure how cross bars would add to the interior noise, maybe unless someone didn't bolt them down right, I think there is a thread here on that.

Thanks,

 

The Bridgestones are noisy, and I switched them out with Michelin Defenders. Much quieter.

 

I had a set of Bridgestones that came from the Plant on my 2017 GMC Sierra 3500, and I thought the Noise and Rough ride I was getting was normal for a heavy 4X4 truck, and because it came with a Full Size spare I ended up getting three more when their short life came to and end, and when they wore out I decided to go with a set of Cooper Discoverer HT3 All Season, and as soon as I pulled onto the Highway after they were installed I knew I made a mistake buying the second set of Bridgestones, the Coopers are Quiet and are giving me a Car like ride.

 

took my crossbars off. no noticeable difference in ride quality, noise or gas mileage.

 

I left mine on. They actually look good up there.

 

You can always bring a tire gauge the next time you test drive.

 

So after 9 days at the dealer and a regional tech checking my vehicle they claim a decibel reading of 95-99 inside the car at 70 MPH is normal. sigh.....

 

Oh my!

 

Wow!

 

I find 95-99db as being typical difficult to believe.

 

I agree with you 100%. From my reading most cars are between 60-70 decibel going 70 MPH. My car was at 99 and they added some sound deadening material and it brought it down to 95. Needless to say it is still way too loud for an extended road trip. I have a call into the manager at the dealer now and I am waiting for Toyota Consumer Affairs to get back to me.

 

Yeah and dealer and Toyota is advising me I need to pick up the vehicle tomorrow it’s normal. My 2019 highlander loaner I’m in average 65 decibels going 70 mph.

 

I'd take it to another dealership and get their opinion. As a motorcycle rider, I always wore ear plugs when riding (the el-cheapo Harbor Freight ones, but still) because the noise created fatigue which creates unsafe conditions. 95 decibels seems about right for motorcycle riding...I can't imagine even trying to take a short trip of an hour with noise that loud. That may make me sound old, but I value my hearing and my safety.

 

According to my dealer since a regional tech signed off on it being normal it can't be looked at again under warranty. Thus the reason I am waiting to hear back from Toyota Corporate.

 

I agree tires can make a huge difference. Too bad that they don't do crap for wind noise from a mirror

 

I removed the cross bars; no major difference.

 

Whole topic is subjective. It ain't so much what you drive, as where you drive it

Vehicle noise.. on a scale of ten on the Sound-o-Meter
(multiply wet vs. dry surfaces by 1.5)

Stopped..................................0
Drive surface @ 25 mph:
New smooth asphalt....... .....1
Old asphalt...........................3
Crushed marble...................4
Flat concrete........................5
Grooved asphalt..................6
Quarter size gravel clatter...7
Grooved concrete...............8
Bridge steel grid deck... .....9

Cranked JBL 11 speaker system.....10+

Analysis: A good sound system will always Trump $hitty tires and $hitty road surfaces in any vehicle.

 

Didn't have to swap anything...retired and spend some spare time in the quad state area visiting different dealers to get free coffee and test riding every vehicle they are foolish enough to let me drive.

I test road Highlander's both w/18"s and 20"s on highways, teacup hills and hairpins before settling on the Platinum.

If ride is the only consideration the 18's with larger sidewalls definitely ride smoother than the 20's, but the 20"s (especially on Platinums which have torque vector steering) bring exceptional handling to the vehicle particularly in emergency maneuvers to a whole different level....and the number of times the salesman yelled expletives was the proof of it.

No idea how or if or wise to swap 18s for 20s on a Platinum....re: how it will affect the design or calibration of its torque vector steering system over Highlanders with native 18s w/o TVS.

 

I removed cross bars in mine, and felt it's quieter on highway. But it's subjective.

 

I can not recall the last time I actually opened my sunroof, but if you just open the shade the noise goes up a lot. So if you are driving with it always open and you find the car loud, close it and listen......

This is especially true of the OP's subject test Platinum as it has the bigger sunroof.