my RX350 has a loud engine noise and also high level of wind noise (to compare with ES330, the only other Lexus I had driven). It is a disappointment on my part. I thought Lexus vehicles suppose to be quite and smooth.

Is it normal on the RX line, or is there something wrong with my car?

 

I think something is wrong with yours. Ours is just as loud as a SUV should be & a lot less noisey then most others we have been in.
Take it in & go for a test drive with their mechanic.

 

Compared to other Lexus cars the RX line is more noisy. That is normal. Personally, I'm one that likes to hear a little engine and exhausts so it doesn't bother me. The wind noise is a little more than I'd like though. One of the largest complaints on the RX on this forum back when the RX came out in 2003 was wind noise and engine noise compared to other Lexus cars. They are not that bad, but since most of us have had other Lexus cars in comparison it is noisy.

 

ive never noticed that problem b4...but then again sometimes i wish that i heard more from the car since its so quiet. but yea compared to other lexus models it is more noisy, but i would hardly consider that a problem

 

might be your tires...if you have on the goodyear eagles, they are rated close to one of the most noisiest tires. im going to try the michelin energy ones...they are suppose to be better.

 

I test drove an RX400h a few days ago. I also had a Camry loaner while my BMW was in the shop. The RX was quite quiet until we hit the freeway at 70MPH. However, noise was not bad. It was quieter than a Camry, about the same as my 97 ES300.

Overall I think it is fine. Sunroofs are the cause for a lot of wind noise going down the road.

Thicker glass, more insulation, etc. all contribute to vehicle weight. I am not sure how far Lexus can go for wind noise and keep the pricing reasonable.

 

How loud is compared to what I here inside of my RX300 in this video?

http://www.youtube.com/watch?v=VSYwjEO19bg

 

Judging by your video, I would say the RX400h is twice as quiet with the car floored. So some improvements have been made.

 

Recently, I replaced the spark plugs (a new set of Torquemasters) and also the oil (M1 0W40 to German Castrol 0W30) and my RX300 is a lot quieter. Someone who was riding home with me commented at a light they could barely tell the engine was on, however, when I hit WOT of course it sounds just like in the video (but due to exhaust/intake modifications).