I recently noticed that the ride didn't seem quite as good with my 04 LS430. I thought it may be time for new shocks, although none are leaking and the bounce test seemed fine. I checked the tire pressure, and I was low, around 29 and 30 psi in each tire. I added air and got them back to around 33 psi, and everything seems to be better.

Is this normal? Is the LS430's ride that sensitive to tire pressure? Normally reducing tire pressure makes the ride softer. Why did lower tire presure make my car seem to ride rougher?

 

My 06 LS 430 rides/handles the best at around 34PSI... May also depend on the tires and their condition.

 

Are you on 17 or 18" tires ? I run 32 in my 17" tires and I think they are the best at that. Up over 35 PSI tends to feel bumps in the road a little more.

I've had this car for like 8 years now, so trust me, I know...

 

'tis the season for low tire pressure

The same topic recently came up in the IS section.

Tire pressures should be checked once a month, at least.

 

Nitrogen really works to maintain your pressure. I checked my tire pressure the other day, as It was last pressurized 4000 miles ago during balance and rotation, and the pressure is exactly the same as 4000 miles ago. I'm running Michelin Primacy MXV4 17".

 

My 06 LS 430 door placard states 32PSI and I usually run 34PSI. My stock tires are 17" and it runs fantastic at 34. Any PSI over 34 and yes, it does get slightly rougher. Lexus was pretty close on what is best concerning the tire pressure for this car.

 

For the 3 years my car wandered, I was changing tires, wheels and pressures non stop. I know for sure tire pressure make quite a big difference in the ride of my LS, and different wheels/tires work better at different pressures. Its an easy thing to change, so just experiment and find the one you like.

 

I keep mine at 30psi in my 2002 per glove box specs. Running 16" Michelin Primacy MXV4 98V rated. I check it weekly. Rides smooth for me.

 

I just found it odd that lower pressure seemed to make the ride rougher. Usually the other way around.