Tire Pressure After Lowering Car

RacerGT said:
I always run max psi because more pressure = less rolling resistance in the front. I typically have 28-32psi for daily driving in the rear.

This is a good concept at the track, but not for daily driving. You would actually have less contact area and a harsher ride if you put the tire on max pressure, plus IMO that's kinda unsafe. No you dont have to run different tire pressure when you lower the car. I typically run 33-34lbs on the street for DD.
 
From another thread I posted in:

Forget the 44 psi max. Those numbers indicate that it's a higher quality tire, and you'd only run close to that when road-racing. The goal with tire pressures is to have the same loaded radius on the front and back wheels. That means from the hub to the ground. Since the front of the car weighs more than the rear, that's why you want more pressure in the front than the rear.

I run from 35-36 in the front and 32 in the rear. Yes, I sacrifice a bit of turn-in sharpness by not running higher, but the ride suffers too much if I go any more. I run 32 in the rear to match the radius in the front.

Basically, just start at LEAST with what Ford recommends and add more and more pressure (but not beyond max) until the ride suffers too much. Higher pressure is generally better for the tire anyway since it runs cooler - heat cycling wears out a tire and also makes it harder - less traction.