2010 RX350 very rough ride - suggestions

[Spotyou58]

It is 13 yrs old and 129,000 miles and our vehicle rides really rough. We have 17” tires and reduced the air pressure to 32. We have not changed any suspension parts. Its bad enough riding up front and with family visiting recently found out the back seat is much worse. Any thoughts would be appreciated.

[Bd3max]

What I've done with my 2015 Rx350 was to go up a size in the "aspect ratio" of the tires. I went from a "60 series" to a "65" and gained 1" of total height= 1/2" more height of each sidewall- the more you have, the more "give" there is over bumps- also keep the PSI around 31. And I researched and finally picked new tires that excelled in ride comfort(according to TireRack testing) Also the bigger size has no clearance issues. I'm happy now.

[jolimojo]

I'm also on the hunt for getting better ride quality from my 2010 Lexus Rx 350 as it seems uncharacteristically firm... our 1999 RX 300 with large 16" tires was a smoother ride! I've done extensive research on the suspension differences of this gen (2010-2015) and all I can see that may affect it is there was a "sport" suspension offered, but is not easily identifiable. You may also have the towing package which mine has, I also have the 19" wheels. But call a dealer and give them your VIN, they can identify if you have the "sport" suspension or not as I couldn't find anywhere else how to identify it. I just called a dealer today and they confirmed that I do NOT have the sport suspension, but the towing package "may" affect the ride but they couldn't tell me what's different about it exactly. I may still take off one of the back wheels and see if I can identify the rear shock part number and see if it matches the "sport" or "regular" shock part number...

For reference, I've been using parts.lexus.com to identify part numbers and they have one strut/shock that is labeled as "sport package" and another part without that label, I guess just meaning "regular".

- FRONT SPRING & SHOCK ABSORBER. 2010 Lexus RX 350 VIN starts with 2 | Lexus Parts & Accessories Online

If I truly do have the "regular" suspension, the only methods I have left to "engineer" my way to a softer ride is to replace all wheels with the 18" wheels and get tires that are 1 step up in aspect ratio in addition to that, or to keep 19" wheels and replace tires with 1 step up in aspect ratio. Either way, I'm planning on getting new/fatter tires and keeping pressures on the low side (29-30 psi) to help keep the ride as compliant as possible. Those are the best options I think we have at this point.

When I first bought this car from a private seller, the ride was MUCH worse, nearly unbearable. I found out they pumped up the tires to 40 psi, lowering them back to 30 psi has made a SUBSTANTIAL difference and transformed the ride from what it was, however, still not perfect and is definitely on the firm side. However, the tires are getting older now and the compound is harder as they are long-life tires (Goodyear Assurance MaxLife).

I think the winning transformation for me will be to replace wheels with 18" and also put new tires on at that time with taller aspect ratio. But that requires spending $800-$1000 on wheels, plus new tires for that price again. Or secondarily, keeping the 19" wheels and just go for new/fatter tire... still haven't decided if I am willing to spend the money to replace the wheels when just new tires may be "fine". 

Unrelated note... anyone selling good condition 18" wheels or want to even trade for a 19" set? 😄