Re. RX 2024 RX350 with 21 inch tires. The stated tire pressure is 33 psi. Has anyone tried different psi to see if better ride as long as the changes are safe.

 

I'm running 35/36 and love the ride.

 

Thanks. That is what I have them at now.

 

I'm running 38 psi in each tire. Find the ride incredibly quiet comfortable and getting 38 miles per gallon. I've always had it 3-4 extra pounds per tire.

 

I run 38F, 35R. That tightens up the steering response a bit without diminishing ride comfort.

I admit that I prefer a firmer ride. When test-driving, I thought the RX's handling was too soft & sloppy, but it is acceptable now that I've changed our suspension and steering settings.

 

Since your 500H has a tunable suspension, I suspect it wouldn't be an apples-to-apples comparison with 350/H/450H+ - as the latter don't have the additional degrees of freedom that your tunable suspension provides. I'm personally so far sticking to the 36-38 psi that dealer set it up with at delivery, so far - for the benefits to mpg. However, while it gives a nice ride so long as the pavement is in good shape, the slightest of imperfections in usually poor California roads lead to an uncomfortable ride that would have been mitigated by 19/20 inch wheels with thicker sidewalls, or a lower tire pressure.

 

Watch out for (dumb) folks at the jiffy type oil places, which we religiously avoid....my wife's company assessed such places (they are horror shows) and one fascinating interaction I had with a manager there (ack) started when I saw him adjusting the air in my tires, which I knew to be just the way I wanted it. When they were done, I pulled out my gauge and noted all the tires were at 44 psi...ouch! So I protested rather vehemently, pointing to the air pressure notification just inside the door which called for 34 psi or whatever it was. But the manager was adamant, pointing to the MAX pressure 44 psi written on the tire....no amount of talking could persuade this person that MAX pressure isn't suggested pressure, but what can you do?

 

I run 33psi per the door placard. However, the dealer keeps bumping to 35psi (delivery and 5k service). We're moving next week so our selling dealer will not see our vehicle again, but I'm interested to see what the new dealer does at the 10k service (after that, I'll be the service station).

 

I've always run at least 10% above the tag. Seems to be fine.

 

A few extra PSI assures that the pressure won't get too low if the weather turns cool.

Who else remembers the 'Ford Exploder" situation?
https://en.wikipedia.org/wiki/Firest...re_controversy

 

I'm one of those guys who reads the sidewall that states, "Do not inflate above XX PSI" and think, "Why does EVERY Joe Blow who works on my car assume that's the recommended tire pressure?! It's clearly the MAXIMUM!" And call me crazy, but I don't exceed the maximum - at least with tire pressure. The speed limit is a different story.

Seriously, doesn't anyone understand the difference between the maximum psi vs the recommended tire pressure for your vehicle?!? Here's an excellent article detailing the difference in case anyone is interested:
https://tiregrades.com/tire-maintena...your-tires-be/

For my 2024 RX350h, the recommended psi is 33 pounds. Because it's summer, I inflate them when they're cold to 34 pounds. They might get up to 35 or 36 while driving. But EVERY TIME I come back from the tire shop or any service, they're inflated to 37 psi or more! ALL of my vehicles have been OVER INFLATED after getting tires or an oil change. Argh!!!

 

I don't trust dealers/tire shops to properly torque lug bolts, either. Just sayin'.

 

It also assures that you'll not be running the psi recommended by the vehicle's manufacturer. They did the testing and selected the recommended pressure based on handling, performance, and mileage characteristics. Higher pressures will only firm up your ride and possibly cause poor tire wear too.

 

Over inflating will definitely cause un even tire wear. I always use the number on the door tag religiously in spite of the dealers always over inflating them and usually go 60,000 miles on each set. I think the overinflators want to sell tires.

 

I've often thought that as well! That the over inflators just want to sell tires!