The tire will have the maximum allowable pressure printed on the sidewall of the tire. If your vehicle does not have the original equipment tires on it, you wouldn't be filling the tires to the proper pressure anyway. Look on the sidewall of the tire, it's mandatory for tire producers to label the tire with the proper inflation rate
It makes no difference if you have 16", 17", or 18" wheels. The correct tire pressure is the same for all of these sizes. The correct pressure is listed in your owners manual and on the drivers door post.
45 psi..
I think it is 35 pounds of pressure in the winter and 32 in the summer.
If your Jetta came with 16 inch wheels as original equipment the correct tire pressure is located on a plaque mounted on the driver's side door post. If the 16 inch tires are not original to your car, the tire pressure on my 2007 jetta with 16 inch wheels is 34 pounds front and rear.
33psi back + front
30 psi
Assuming you have stock tires, which is supplied by the company itself, the best and most suitable tyre pressure is 36psi for the front wheels, and 33psi for the rear wheels ! Good luck !
between the rear wheels
This is normal and is caused by the weight of the wheels, and the dampers pushing them down. All you need to do to correct this is take the jack out from underneath the vehicle and drive it off, the wheels will settle down once you start driving.
30 pounds for all four wheels for normal speed and weight.
Website I found says 76psi front and 44psi for rear wheels.
Check Tire Pressure. If correct, check that the factory pressure monitor installed on stock wheels is still good.