Anyone else want the look of a firmer tire sidewall? Help?

[g3ride69]

2007 saturn aura xe 3.5
225/50-17

Currently have pirelli p4 tires on it and at 30psi they all look like they are 25psi too low. The pirelli's are an 80k mile tire and are in great shape. (Although 1 has a plug).

Im not saying i need a LT tire... But is there a {P}assenger tire that doesn't look flat in the 225/50-17 on an 07 Aura??

Ride feels a little bit squishy.
I normally drive for mpg.

Is there a go to swap? A rim/tire from a Malibu or g6?

I wouldn't mind going down to a 16" or possibly a 15" rim/tire combo. I like having 2 sets of rims for my vehicles. Never know in Michigan winters when a swap will be needed.

I have a couple tire size converter sites i use to make sure i wouldnt change the overall dimensions by too much (+/-3%).

I saw an aura that had 225/60-17 tires on it. Extra width looked ok but still appeared low on air. (My converter said not to put that size on mine. Aura's with other stock sizes may be appropriate for the 225/60-17.... Im not sure.)

All comments are appreciated.

Thanks!