I know you have posted issues with the ride...that's why you have issues with the ride lol

 

^^^ Very True!
I have all my vehicles tires filled with nitrogen and keep them inflated to the manufacturers recommended PSI located on the door post.

 

Ok to all you guys said, but...

What to trust? both my gauges, when showing 33, turn out to display 36 on the dashboard... so do I trust the dashboard or the gauges?

 

Trust your gauge

 

Probably a stupid question, but no one is specifying their wheel size here when responding. Would you change your PSI based on tire/wheel size? I have the 19's on my 460L. Frankly I have never paid attention to what the dash reading tells me - I would only be alarmed if the low tire warning came on. But since I"m hearing folks say going down on the PSI is leading to a better ride, I will start paying attention and modifying to get in the right range.

Also, I think WaWa gas stations are regional (??) but do you guys who use them find their air pressure stations to give accurate readings? I like going to them because you can set the system to a certain PSI and it will automatically stop pumping air when it reaches that point. Plus, it's free!

 

+1, I would trust the gauge assuming it's working properly

 

The TPMS pressure sensors in your car are as accurate or more accurate than any handheld tire pressure gauge. You can trust the pressures displayed in your dash panel.

 

But if you have a gap of 3PSI and two gauges agree and the car disagrees I'd trust the two gauges.

 

I use a digital pressure gauge and the TPMS pressure sensors are spot on with the handheld gauge. I run either 33 or 34 psi in my 245/45/VR19 tires. I always run 35 PSI in the spare so I can identify it on the TPMS screen.

Dennis

 

Smart thinking on the spare. I can never tell which tire is which on the display of my '10 460 or the '10 LX570. I'm going to set the spare to a higher number as well.

 

Luckily in 13 they changed the pressure readout:

 

Tire pressure always depends on the wheeel and tire size. I used to run my old LS430 with 17" wheels at 32 PSI. I found if I went up to 36 PSI, it would get a little hard riding. 30 psi and it felt slugish like under inflated tires.

Funny things you learn when owning a car for like 12 years....

 

I benchmark my spare at 33 PSI and then I inflate it to 40 PSI. It's sort of a hassle to add air to the spare. So, if you inflate it to 40 PSI it will take about 2 years or longer for the permeation loss to get the pressure back to 33 PSI.

 

No. No it isn't.

I had 32 PSI in there for the first couple of weeks. Was the same.

The problem is, my RR strut/damper throws a code which means I get permanent 'sport' setting on my suspension.

I knew that button didn't really do anything!

:-)

 

Not saying you're lying, but having had this car for 2 years and having had several other Lexus vehicles, 40 PSI absolutely has a significant impact on the ride. The car absolutely rides harder on 40PSI than it does on 33 or 32, as Junglequac also found and numerous other members have found. Not saying that is your only issue, but running 40 PSI in the tires is absolutely contributing significantly to your hard ride.