Nitrogen does help keep constant pressure. The lack of moisture in the tire is a big factor.

For street cars it is not a big issue as it is on race cars that use tire pressure to control handling.

What pressure you run has more to do with the loads you carry. the more load you carry the more pressure you run in the tire.

My pressures cold to warm run about 2-3 pounds this time of year.

I set my pressures at around 30 PSI and watch and adjust depending on tire wear. too much the center of the tire will wear at a faster rate and too little the outer edges will wear.

No one pressure is right for everyone. Weight and driving styles will require different pressures.

The main thing is to keep the tires up on pressure as low pressure will make a tire heat up and it will do more damage to the tire than anything. Heat kills tires.

In the past it was a weekly thing to check tires and today they are so good people put them on and forget them even though they still need some care.