I set my tires at the recommended 35psi on my NX base with 17" tires. The TPMS in the car reads 34psi. Close enough, but I think the gauge is more accurate since it is a rather expensive one.

 

Why do the 17" tires require 35psi and the 18" only 32? How low could you set your psi on the 17" and not be under inflated? I have had them down to 32psi and loved the ride but the combined mileage dropped down to 23-24 mpg. Car came with Yokohama tires.

 

I have a base NX with 17" tires. I put them down to 32 from the recommended 35psi and the ride was much smoother, but my mileage dropped about 2 mpg. I'm not sure if that would be considered seriously under inflated or just less efficient economically.

 

32 psi is kind of low, thats why I started this thread. I think Lexus recommend 32 psi for the 18” because the ride is stiff for a Lexus. Riding on 32 psi in the 17” tires will not harm your car, maybe just your wallet with the slightly lower mpg. Check your tire thread to make sure the outside is not wearing faster the middle.

 

With this pressure setting you will have bad MPG and the tires will wear on outer edges fast.

 

I have 2017 NX200T the same 17" tires. I used to kept them at 35 PSI. The ride was hash and bumpy. Last month i had my car serviced at dealer. i got a loaner is NX300 AWD. They are 17" and their tires were inflated at 30 PSI. The ride is very smooth and handling is perfect.
Since then, I inflated my at 30 PSI. I haven't seen any difference of tires weared or decrease of fuel mileage yet.

 

If you have a decent gauge, believe it!!! Sensor systems suck!

 

That has been my experience in the past, but with my 2017 F-Sport all four sensors have always reflected the same pressures my digital tire gauge indicates.

I used to check with the gauge at least twice per month, but I no longer do that knowing the sensors are accurate.

 

Does everyone know how to solve the disappear number of tire pressure TPMS? I tried to reset it but it still blanks on screen ---. Thank you in advance for all your advice.

 

For future reference, we had new tires put on our 2019 NX and it showed the dashes on the TPMS display for about a day or so. Dashes usually mean that the system sees the sensors and it is configuring it. If the dashes stays on after days, that usually mean, for some reason, the system cannot configure the sensors.