we have been through this
the higher the pressure the rougher the ride, but the better the handling (though a bit more dangerous in slippery conditions)
you were complaining about a rough ride, so it was suggested that you go with the Lexus recommendation of 30psi all around
that will give you the ride designed for that car, smooth and quiet
if the ride is still rough after putting the proper 30psi all around, the problem is not the tire pressure
don't know where you read to increase pressure for smooth ride, but it is wrong!
Wise and accurate advice. I always run 32 psi in my car and every time it's been in for service it comes back with at least 36 psi in the tires. I always forget to ask the Svc Dept why they do it and tell 'em not to do it. Maybe one of these times I'll remember.
LexyLuv is it possible the dealer upped the air pressure when your car was in the shop?