Hey guys,

Given the poor road quality, in my country, I am on a quest to make my 2003 UL the smoothest rider as possible.
The original suspension kit has never been replaced in 20 years. The car is currently running on a 225/55 17 inch Michelin Primacy 3 which has more 2k miles left approximately.
I am also identifying and trying to get rid of internal squeaky noises from leather seats, internal plastics and dashboard. Nothing major, but annoying when I imagine how silent this car was when originally launched.

So having my goal in mind for smoothness and noise free ride, which suspension kit and tyre set do you guys recommend given the poor road conditions I face? Also, any tips on getting rid of squeaky noises coming from the dashboard and leather trim is welcome!

 

Honestly a smaller wheel diameter would be helpful in absorbing road imperfections. I don't think you are going to get mush smoother than the factory air suspension (which I assume you have if yours is a UL)

One of the several springs listed in the OEM parts catalogs are for a "rough road package" but nobody here is the states seems to know what the difference is.
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Can you define more specifically the poor road quality? For example, big potholes?

The above post is good advice. Go to 16" wheels. If your original air suspension is working properly, you probably don't need to do anything else.

 

Thanks for your suggestion. Didn't think about going to 16-inch wheels. Definitely, I will consider this if I can source OEM rims at that size. I would like to keep my LS430 closest to the stock look as possible!
All the LS430 UL that came to my country did not include air suspension or cruise control, unfortunately. So, the car has been running on regular struts since ever.

 

Sure. Here are some pictures to illustrate better.
I am wondering if a 17" 60 tyre instead of the recommended 55 would be worth it.
My UL does not have the air suspension, unfortunately.

 

Wouldn't a 17 inch tire with 60-series sidewall make the car sit too tall? I think you would want 225 60/R16.

 

Your struts could be worn also, new OEM standard (not sport) struts would be a good idea.

 

Yeah, replace the entire suspension. Things wear out over time, even if the car doesn't have a ton of mileage. Definitely do OEM parts.

Get the 225 60/R16 tires. Not sure what you have in your country for brands but Continental TrueContact is a great tire. Goodyear Assurance is another great one. Any top rated ultra touring tire is your best bet. Also don't go the full 30 PSI rating that Lexus recommends. Do 28 or 28.5 in each tire. Makes a big difference in ride quality.

Do all these things and your car will float over any bump. Literally brings a smile to my face just writing that.

As for noises in the cabin, I'm not really sure what you can do about that. Others probably have good information if you search the forum. This is an issue not unique to our cars (every vehicle will do this as they age, just how it is), so check out what others in general have done with their vehicles to solve the problem of rattles and squeaks.

 

Thank you for your suggestions.
I will try sourcing OEM 16 inch rims abroad and see if they can be delivered here. I am so used to de 17" look that I think 16" might look tiny. But maybe worth it if comfort is my ultimate goal here.
Meanwhile, I will check if I can get an OEM suspension kit and will change my current Michelin Primacy 3 to 30 PSI or even lower to test it's impact in ride quality.
I was considering getting a Primacy 4 or 4+ but I will take a look at your suggestions.

Reading your comment about smiling while imagining the car floating made me smile too. That's my goal with this car!

 

That is true. I thought about trying to lower the suspension a little to compensate for it, but that may cause some tyre rubbing no?

 

Why would you lower? That is opposite to your goal. The 225x60x16 tire is equivalent in size to 225x55x17. Anyways, no it would not cause tire rubbing assuming OEM wheels.

Here is an old thread about getting a smooth ride which includes a picture of an LS430 with 16" wheels.

https://www.clublexus.com/forums/ls-...rove-ride.html

 

Thank you very much. Very helpful.