For proper maintenance, safety, and maximum fuel economy, you must always maintain recommended tire inflation pressures and stay within the load limits and weight distribution recommended for your vehicle.

All specifications (sizes and pressures) can be found on a label attached to the driver's side center pillar.
Tires and Wheels
Recommended Cold Tire Inflation PressuresHyundai Elantra AD (2016-2020) Owners Manual: Care of Seat Belts
Seat belt systems should never be disassembled or modified. In addition, care
should be taken to assure that seat belts and belt hardware are not damaged by seat
hinges, doors or other abuse.
Periodic inspection
All seat belts should be inspected periodically for wear or damage of any kind.
...
Hyundai Elantra AD (2016-2020) Service Manual: Input Speed Sensor Repair procedures
Inspection
1.
Using the GDS, check the input/output speed sensor waveforms.
A.
Turn OFF the ignition switch.
B.
Connect the GDS to the Data Link Connector(DLC) on the lower crash pad.
C.
Ignition "ON" & Engine "ON".
D.
Check the input/output speed sensor waveforms at high spe ...